Spring Boot Reference


Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Phillip Webb , Dave Syer , Josh Long , Stéphane Nicoll , Rob Winch , Andy Wilkinson , Marcel Overdijk , Christian Dupuis , Sébastien Deleuze Copyright © 2013-2016 Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot ii Table of Contents I. Spring Boot Documentation ...................................................................................................... 1 1. About the documentation ................................................................................................ 2 2. Getting help .................................................................................................................... 3 3. First steps ...................................................................................................................... 4 4. Working with Spring Boot ................................................................................................ 5 5. Learning about Spring Boot features ................................................................................ 6 6. Moving to production ....................................................................................................... 7 7. Advanced topics ............................................................................................................. 8 II. Getting started ........................................................................................................................ 9 8. Introducing Spring Boot ................................................................................................. 10 9. System Requirements ................................................................................................... 11 9.1. Servlet containers ............................................................................................... 11 10. Installing Spring Boot .................................................................................................. 12 10.1. Installation instructions for the Java developer ................................................... 12 Maven installation ............................................................................................. 12 Gradle installation ............................................................................................. 13 10.2. Installing the Spring Boot CLI ........................................................................... 14 Manual installation ............................................................................................ 14 Installation with SDKMAN! ................................................................................. 15 OSX Homebrew installation ............................................................................... 15 MacPorts installation ......................................................................................... 15 Command-line completion ................................................................................. 16 Quick start Spring CLI example ......................................................................... 16 10.3. Upgrading from an earlier version of Spring Boot ............................................... 16 11. Developing your first Spring Boot application ................................................................ 17 11.1. Creating the POM ............................................................................................ 17 11.2. Adding classpath dependencies ........................................................................ 18 11.3. Writing the code ............................................................................................... 19 The @RestController and @RequestMapping annotations .................................. 19 The @EnableAutoConfiguration annotation ........................................................ 19 The “main” method ........................................................................................... 20 11.4. Running the example ........................................................................................ 20 11.5. Creating an executable jar ................................................................................ 20 12. What to read next ....................................................................................................... 22 III. Using Spring Boot ................................................................................................................ 23 13. Build systems ............................................................................................................. 24 13.1. Dependency management ................................................................................ 24 13.2. Maven .............................................................................................................. 24 Inheriting the starter parent ............................................................................... 24 Using Spring Boot without the parent POM ........................................................ 25 Changing the Java version ................................................................................ 26 Using the Spring Boot Maven plugin .................................................................. 26 13.3. Gradle .............................................................................................................. 26 13.4. Ant ................................................................................................................... 27 13.5. Starters ............................................................................................................ 28 14. Structuring your code .................................................................................................. 34 14.1. Using the “default” package .............................................................................. 34 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot iii 14.2. Locating the main application class ................................................................... 34 15. Configuration classes .................................................................................................. 36 15.1. Importing additional configuration classes .......................................................... 36 15.2. Importing XML configuration .............................................................................. 36 16. Auto-configuration ....................................................................................................... 37 16.1. Gradually replacing auto-configuration ............................................................... 37 16.2. Disabling specific auto-configuration .................................................................. 37 17. Spring Beans and dependency injection ....................................................................... 38 18. Using the @SpringBootApplication annotation .............................................................. 39 19. Running your application ............................................................................................. 40 19.1. Running from an IDE ........................................................................................ 40 19.2. Running as a packaged application ................................................................... 40 19.3. Using the Maven plugin .................................................................................... 40 19.4. Using the Gradle plugin .................................................................................... 41 19.5. Hot swapping ................................................................................................... 41 20. Developer tools ........................................................................................................... 42 20.1. Property defaults .............................................................................................. 42 20.2. Automatic restart .............................................................................................. 43 Excluding resources .......................................................................................... 44 Watching additional paths .................................................................................. 44 Disabling restart ................................................................................................ 44 Using a trigger file ............................................................................................ 45 Customizing the restart classloader .................................................................... 45 Known limitations .............................................................................................. 46 20.3. LiveReload ....................................................................................................... 46 20.4. Global settings ................................................................................................. 46 20.5. Remote applications ......................................................................................... 46 Running the remote client application ................................................................. 47 Remote update ................................................................................................. 48 Remote debug tunnel ........................................................................................ 48 21. Packaging your application for production ..................................................................... 49 22. What to read next ....................................................................................................... 50 IV. Spring Boot features ............................................................................................................ 51 23. SpringApplication ......................................................................................................... 52 23.1. Customizing the Banner .................................................................................... 52 23.2. Customizing SpringApplication .......................................................................... 53 23.3. Fluent builder API ............................................................................................. 54 23.4. Application events and listeners ........................................................................ 54 23.5. Web environment ............................................................................................. 55 23.6. Accessing application arguments ....................................................................... 55 23.7. Using the ApplicationRunner or CommandLineRunner ........................................ 56 23.8. Application exit ................................................................................................. 56 23.9. Admin features ................................................................................................. 56 24. Externalized Configuration ........................................................................................... 58 24.1. Configuring random values ............................................................................... 59 24.2. Accessing command line properties .................................................................. 59 24.3. Application property files ................................................................................... 59 24.4. Profile-specific properties .................................................................................. 61 24.5. Placeholders in properties ................................................................................. 61 24.6. Using YAML instead of Properties ..................................................................... 61 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot iv Loading YAML .................................................................................................. 62 Exposing YAML as properties in the Spring Environment .................................... 62 Multi-profile YAML documents ........................................................................... 62 YAML shortcomings .......................................................................................... 63 24.7. Type-safe Configuration Properties .................................................................... 63 Third-party configuration .................................................................................... 65 Relaxed binding ................................................................................................ 65 Properties conversion ........................................................................................ 66 @ConfigurationProperties Validation .................................................................. 66 25. Profiles ....................................................................................................................... 68 25.1. Adding active profiles ....................................................................................... 68 25.2. Programmatically setting profiles ....................................................................... 68 25.3. Profile-specific configuration files ....................................................................... 69 26. Logging ....................................................................................................................... 70 26.1. Log format ....................................................................................................... 70 26.2. Console output ................................................................................................. 70 Color-coded output ............................................................................................ 71 26.3. File output ........................................................................................................ 72 26.4. Log Levels ....................................................................................................... 72 26.5. Custom log configuration .................................................................................. 73 26.6. Logback extensions .......................................................................................... 74 Profile-specific configuration .............................................................................. 75 Environment properties ...................................................................................... 75 27. Developing web applications ........................................................................................ 76 27.1. The ‘Spring Web MVC framework’ .................................................................... 76 Spring MVC auto-configuration .......................................................................... 76 HttpMessageConverters .................................................................................... 77 Custom JSON Serializers and Deserializers ....................................................... 77 MessageCodesResolver .................................................................................... 78 Static Content ................................................................................................... 78 ConfigurableWebBindingInitializer ...................................................................... 79 Template engines .............................................................................................. 79 Error Handling .................................................................................................. 80 Custom error pages .................................................................................. 81 Mapping error pages outside of Spring MVC .............................................. 81 Error Handling on WebSphere Application Server ....................................... 82 Spring HATEOAS .............................................................................................. 82 CORS support .................................................................................................. 82 27.2. JAX-RS and Jersey .......................................................................................... 83 27.3. Embedded servlet container support .................................................................. 84 Servlets, Filters, and listeners ............................................................................ 84 Registering Servlets, Filters, and listeners as Spring beans ......................... 84 Servlet Context Initialization ............................................................................... 84 Scanning for Servlets, Filters, and listeners ................................................ 85 The EmbeddedWebApplicationContext ............................................................... 85 Customizing embedded servlet containers .......................................................... 85 Programmatic customization ...................................................................... 86 Customizing ConfigurableEmbeddedServletContainer directly ...................... 86 JSP limitations .................................................................................................. 86 28. Security ...................................................................................................................... 87 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot v 28.1. OAuth2 ............................................................................................................ 88 Authorization Server .......................................................................................... 88 Resource Server ............................................................................................... 88 28.2. Token Type in User Info ................................................................................... 89 28.3. Customizing the User Info RestTemplate ........................................................... 89 Client ................................................................................................................ 89 Single Sign On ................................................................................................. 90 28.4. Actuator Security .............................................................................................. 91 29. Working with SQL databases ....................................................................................... 92 29.1. Configure a DataSource ................................................................................... 92 Embedded Database Support ............................................................................ 92 Connection to a production database ................................................................. 93 Connection to a JNDI DataSource ..................................................................... 94 29.2. Using JdbcTemplate ......................................................................................... 94 29.3. JPA and ‘Spring Data’ ...................................................................................... 94 Entity Classes ................................................................................................... 95 Spring Data JPA Repositories ........................................................................... 96 Creating and dropping JPA databases ............................................................... 96 29.4. Using H2’s web console ................................................................................... 97 Changing the H2 console’s path ........................................................................ 97 Securing the H2 console ................................................................................... 97 30. Using jOOQ ................................................................................................................ 98 30.1. Code Generation .............................................................................................. 98 30.2. Using DSLContext ............................................................................................ 98 30.3. Customizing jOOQ ............................................................................................ 99 31. Working with NoSQL technologies ............................................................................. 100 31.1. Redis ............................................................................................................. 100 Connecting to Redis ........................................................................................ 100 31.2. MongoDB ....................................................................................................... 100 Connecting to a MongoDB database ................................................................ 100 MongoTemplate .............................................................................................. 101 Spring Data MongoDB repositories .................................................................. 102 Embedded Mongo ........................................................................................... 102 31.3. Neo4j ............................................................................................................. 102 Connecting to a Neo4j database ...................................................................... 103 Using the embedded mode .............................................................................. 103 Neo4jSession .................................................................................................. 103 Spring Data Neo4j repositories ........................................................................ 103 Repository example ......................................................................................... 104 31.4. Gemfire .......................................................................................................... 104 31.5. Solr ................................................................................................................ 104 Connecting to Solr .......................................................................................... 104 Spring Data Solr repositories ........................................................................... 105 31.6. Elasticsearch .................................................................................................. 105 Connecting to Elasticsearch ............................................................................. 105 Spring Data Elasticsearch repositories ............................................................. 106 31.7. Cassandra ...................................................................................................... 106 Connecting to Cassandra ................................................................................ 106 Spring Data Cassandra repositories ................................................................. 106 31.8. Couchbase ..................................................................................................... 107 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot vi Connecting to Couchbase ................................................................................ 107 Spring Data Couchbase repositories ................................................................ 107 32. Caching .................................................................................................................... 109 32.1. Supported cache providers ............................................................................. 109 Generic ........................................................................................................... 110 JCache ........................................................................................................... 110 EhCache 2.x ................................................................................................... 111 Hazelcast ........................................................................................................ 111 Infinispan ........................................................................................................ 111 Couchbase ...................................................................................................... 112 Redis .............................................................................................................. 112 Caffeine .......................................................................................................... 112 Guava ............................................................................................................. 113 Simple ............................................................................................................ 113 None ............................................................................................................... 113 33. Messaging ................................................................................................................ 114 33.1. JMS ............................................................................................................... 114 ActiveMQ support ............................................................................................ 114 Artemis support ............................................................................................... 114 HornetQ support .............................................................................................. 115 Using a JNDI ConnectionFactory ..................................................................... 115 Sending a message ........................................................................................ 116 Receiving a message ...................................................................................... 116 33.2. AMQP ............................................................................................................ 117 RabbitMQ support ........................................................................................... 117 Sending a message ........................................................................................ 118 Receiving a message ...................................................................................... 118 34. Calling REST services ............................................................................................... 120 35. Sending email ........................................................................................................... 121 36. Distributed Transactions with JTA .............................................................................. 122 36.1. Using an Atomikos transaction manager .......................................................... 122 36.2. Using a Bitronix transaction manager .............................................................. 122 36.3. Using a Narayana transaction manager ........................................................... 123 36.4. Using a Java EE managed transaction manager .............................................. 123 36.5. Mixing XA and non-XA JMS connections ......................................................... 123 36.6. Supporting an alternative embedded transaction manager ................................ 124 37. Hazelcast .................................................................................................................. 125 38. Spring Integration ...................................................................................................... 126 39. Spring Session .......................................................................................................... 127 40. Monitoring and management over JMX ...................................................................... 128 41. Testing ...................................................................................................................... 129 41.1. Test scope dependencies ............................................................................... 129 41.2. Testing Spring applications ............................................................................. 129 41.3. Testing Spring Boot applications ..................................................................... 129 Detecting test configuration .............................................................................. 130 Excluding test configuration ............................................................................. 131 Working with random ports .............................................................................. 131 Mocking and spying beans .............................................................................. 132 Auto-configured tests ....................................................................................... 132 Auto-configured JSON tests ............................................................................. 133 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot vii Auto-configured Spring MVC tests ................................................................... 134 Auto-configured Data JPA tests ....................................................................... 135 Auto-configured REST clients .......................................................................... 136 Auto-configured Spring REST Docs tests ......................................................... 136 Using Spock to test Spring Boot applications .................................................... 137 41.4. Test utilities .................................................................................................... 138 ConfigFileApplicationContextInitializer ............................................................... 138 EnvironmentTestUtils ....................................................................................... 138 OutputCapture ................................................................................................. 138 TestRestTemplate ........................................................................................... 138 42. WebSockets .............................................................................................................. 140 43. Web Services ............................................................................................................ 141 44. Creating your own auto-configuration ......................................................................... 142 44.1. Understanding auto-configured beans .............................................................. 142 44.2. Locating auto-configuration candidates ............................................................ 142 44.3. Condition annotations ..................................................................................... 142 Class conditions .............................................................................................. 143 Bean conditions .............................................................................................. 143 Property conditions .......................................................................................... 143 Resource conditions ........................................................................................ 143 Web application conditions .............................................................................. 143 SpEL expression conditions ............................................................................. 144 44.4. Creating your own starter ................................................................................ 144 Naming ........................................................................................................... 144 Autoconfigure module ...................................................................................... 144 Starter module ................................................................................................ 145 45. What to read next ..................................................................................................... 146 V. Spring Boot Actuator: Production-ready features .................................................................. 147 46. Enabling production-ready features ............................................................................ 148 47. Endpoints .................................................................................................................. 149 47.1. Customizing endpoints .................................................................................... 150 47.2. Hypermedia for actuator MVC endpoints .......................................................... 150 47.3. CORS support ................................................................................................ 151 47.4. Adding custom endpoints ................................................................................ 151 47.5. Health information .......................................................................................... 151 47.6. Security with HealthIndicators ......................................................................... 152 Auto-configured HealthIndicators ...................................................................... 152 Writing custom HealthIndicators ....................................................................... 152 47.7. Application information .................................................................................... 153 Auto-configured InfoContributors ...................................................................... 153 Custom application info information .................................................................. 154 Git commit information ..................................................................................... 154 Build information ............................................................................................. 154 Writing custom InfoContributors ....................................................................... 154 48. Monitoring and management over HTTP .................................................................... 156 48.1. Securing sensitive endpoints ........................................................................... 156 48.2. Customizing the management endpoint paths .................................................. 156 48.3. Customizing the management server port ........................................................ 157 48.4. Customizing the management server address .................................................. 157 48.5. Disabling HTTP endpoints ............................................................................... 157 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot viii 48.6. HTTP health endpoint access restrictions ........................................................ 157 49. Monitoring and management over JMX ...................................................................... 159 49.1. Customizing MBean names ............................................................................. 159 49.2. Disabling JMX endpoints ................................................................................. 159 49.3. Using Jolokia for JMX over HTTP ................................................................... 159 Customizing Jolokia ......................................................................................... 159 Disabling Jolokia ............................................................................................. 159 50. Monitoring and management using a remote shell ....................................................... 161 50.1. Connecting to the remote shell ........................................................................ 161 Remote shell credentials ................................................................................. 161 50.2. Extending the remote shell .............................................................................. 162 Remote shell commands ................................................................................. 162 Remote shell plugins ....................................................................................... 162 51. Metrics ...................................................................................................................... 163 51.1. System metrics ............................................................................................... 163 51.2. DataSource metrics ........................................................................................ 164 51.3. Cache metrics ................................................................................................ 164 51.4. Tomcat session metrics .................................................................................. 165 51.5. Recording your own metrics ............................................................................ 165 51.6. Adding your own public metrics ....................................................................... 165 51.7. Special features with Java 8 ........................................................................... 166 51.8. Metric writers, exporters and aggregation ......................................................... 166 Example: Export to Redis ................................................................................ 166 Example: Export to Open TSDB ...................................................................... 167 Example: Export to Statsd ............................................................................... 168 Example: Export to JMX .................................................................................. 168 51.9. Aggregating metrics from multiple sources ....................................................... 168 51.10. Dropwizard Metrics ....................................................................................... 169 51.11. Message channel integration ......................................................................... 169 52. Auditing ..................................................................................................................... 170 53. Tracing ..................................................................................................................... 171 53.1. Custom tracing ............................................................................................... 171 54. Process monitoring .................................................................................................... 172 54.1. Extend configuration ....................................................................................... 172 54.2. Programmatically ............................................................................................ 172 55. What to read next ..................................................................................................... 173 VI. Deploying Spring Boot applications ..................................................................................... 174 56. Deploying to the cloud ............................................................................................... 175 56.1. Cloud Foundry ................................................................................................ 175 Binding to services .......................................................................................... 176 56.2. Heroku ........................................................................................................... 176 56.3. OpenShift ....................................................................................................... 178 56.4. Boxfuse and Amazon Web Services ................................................................ 178 56.5. Google App Engine ........................................................................................ 179 57. Installing Spring Boot applications .............................................................................. 180 57.1. Unix/Linux services ......................................................................................... 180 Installation as an init.d service (System V) ....................................................... 180 Securing an init.d service ........................................................................ 181 Installation as a systemd service ..................................................................... 182 Customizing the startup script .......................................................................... 182 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot ix Customizing the startup script with a conf file ................................................... 183 58. Microsoft Windows services ....................................................................................... 185 59. What to read next ..................................................................................................... 186 VII. Spring Boot CLI ................................................................................................................ 187 60. Installing the CLI ....................................................................................................... 188 61. Using the CLI ............................................................................................................ 189 61.1. Running applications using the CLI ................................................................. 189 Deduced “grab” dependencies ......................................................................... 190 Deduced “grab” coordinates ............................................................................. 191 Default import statements ................................................................................ 191 Automatic main method ................................................................................... 191 Custom dependency management ................................................................... 191 61.2. Testing your code ........................................................................................... 192 61.3. Applications with multiple source files .............................................................. 192 61.4. Packaging your application ............................................................................. 192 61.5. Initialize a new project .................................................................................... 193 61.6. Using the embedded shell .............................................................................. 193 61.7. Adding extensions to the CLI .......................................................................... 194 62. Developing application with the Groovy beans DSL ..................................................... 195 63. Configuring the CLI with settings.xml .......................................................................... 196 64. What to read next ..................................................................................................... 197 VIII. Build tool plugins ............................................................................................................. 198 65. Spring Boot Maven plugin .......................................................................................... 199 65.1. Including the plugin ........................................................................................ 199 65.2. Packaging executable jar and war files ............................................................ 200 66. Spring Boot Gradle plugin .......................................................................................... 201 66.1. Including the plugin ........................................................................................ 201 66.2. Gradle dependency management .................................................................... 201 66.3. Packaging executable jar and war files ............................................................ 202 66.4. Running a project in-place .............................................................................. 202 66.5. Spring Boot plugin configuration ...................................................................... 203 66.6. Repackage configuration ................................................................................. 203 66.7. Repackage with custom Gradle configuration ................................................... 204 Configuration options ....................................................................................... 205 66.8. Understanding how the Gradle plugin works .................................................... 205 66.9. Publishing artifacts to a Maven repository using Gradle .................................... 206 Configuring Gradle to produce a pom that inherits dependency management ...... 206 Configuring Gradle to produce a pom that imports dependency management ...... 206 67. Spring Boot AntLib module ........................................................................................ 208 67.1. Spring Boot Ant tasks ..................................................................................... 208 spring-boot:exejar ............................................................................................ 208 Examples ........................................................................................................ 208 67.2. spring-boot:findmainclass ................................................................................ 209 Examples ........................................................................................................ 209 68. Supporting other build systems .................................................................................. 210 68.1. Repackaging archives ..................................................................................... 210 68.2. Nested libraries .............................................................................................. 210 68.3. Finding a main class ....................................................................................... 210 68.4. Example repackage implementation ................................................................ 210 69. What to read next ..................................................................................................... 211 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot x IX. ‘How-to’ guides .................................................................................................................. 212 70. Spring Boot application .............................................................................................. 213 70.1. Troubleshoot auto-configuration ....................................................................... 213 70.2. Customize the Environment or ApplicationContext before it starts ...................... 213 70.3. Build an ApplicationContext hierarchy (adding a parent or root context) .............. 214 70.4. Create a non-web application .......................................................................... 214 71. Properties & configuration .......................................................................................... 215 71.1. Automatically expand properties at build time ................................................... 215 Automatic property expansion using Maven ...................................................... 215 Automatic property expansion using Gradle ...................................................... 215 71.2. Externalize the configuration of SpringApplication ............................................. 216 71.3. Change the location of external properties of an application .............................. 217 71.4. Use ‘short’ command line arguments ............................................................... 217 71.5. Use YAML for external properties .................................................................... 218 71.6. Set the active Spring profiles .......................................................................... 218 71.7. Change configuration depending on the environment ........................................ 218 71.8. Discover built-in options for external properties ................................................ 219 72. Embedded servlet containers ..................................................................................... 220 72.1. Add a Servlet, Filter or Listener to an application .............................................. 220 Add a Servlet, Filter or Listener using a Spring bean ......................................... 220 Disable registration of a Servlet or Filter ................................................... 220 Add Servlets, Filters, and Listeners using classpath scanning ............................ 220 72.2. Change the HTTP port ................................................................................... 221 72.3. Use a random unassigned HTTP port .............................................................. 221 72.4. Discover the HTTP port at runtime .................................................................. 221 72.5. Configure SSL ................................................................................................ 221 72.6. Configure Access Logging .............................................................................. 222 72.7. Use behind a front-end proxy server ................................................................ 222 Customize Tomcat’s proxy configuration ........................................................... 223 72.8. Configure Tomcat ........................................................................................... 223 72.9. Enable Multiple Connectors with Tomcat ......................................................... 223 72.10. Use Jetty instead of Tomcat .......................................................................... 224 72.11. Configure Jetty ............................................................................................. 224 72.12. Use Undertow instead of Tomcat ................................................................... 225 72.13. Configure Undertow ...................................................................................... 225 72.14. Enable Multiple Listeners with Undertow ........................................................ 225 72.15. Use Tomcat 7 ............................................................................................... 226 Use Tomcat 7 with Maven ............................................................................... 226 Use Tomcat 7 with Gradle ............................................................................... 226 72.16. Use Jetty 8 ................................................................................................... 226 Use Jetty 8 with Maven ................................................................................... 226 Use Jetty 8 with Gradle ................................................................................... 227 72.17. Create WebSocket endpoints using @ServerEndpoint .................................... 227 72.18. Enable HTTP response compression ............................................................. 227 73. Spring MVC .............................................................................................................. 228 73.1. Write a JSON REST service ........................................................................... 228 73.2. Write an XML REST service ........................................................................... 228 73.3. Customize the Jackson ObjectMapper ............................................................. 228 73.4. Customize the @ResponseBody rendering ...................................................... 230 73.5. Handling Multipart File Uploads ....................................................................... 230 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot xi 73.6. Switch off the Spring MVC DispatcherServlet ................................................... 230 73.7. Switch off the Default MVC configuration ......................................................... 230 73.8. Customize ViewResolvers ............................................................................... 231 73.9. Velocity .......................................................................................................... 232 74. Logging ..................................................................................................................... 233 74.1. Configure Logback for logging ......................................................................... 233 Configure logback for file only output ............................................................... 234 74.2. Configure Log4j for logging ............................................................................. 234 Use YAML or JSON to configure Log4j 2 ......................................................... 235 75. Data Access ............................................................................................................. 236 75.1. Configure a DataSource .................................................................................. 236 75.2. Configure Two DataSources ........................................................................... 236 75.3. Use Spring Data repositories .......................................................................... 236 75.4. Separate @Entity definitions from Spring configuration ..................................... 237 75.5. Configure JPA properties ................................................................................ 237 75.6. Use a custom EntityManagerFactory ............................................................... 238 75.7. Use Two EntityManagers ................................................................................ 238 75.8. Use a traditional persistence.xml ..................................................................... 239 75.9. Use Spring Data JPA and Mongo repositories .................................................. 239 75.10. Expose Spring Data repositories as REST endpoint ........................................ 239 76. Database initialization ................................................................................................ 240 76.1. Initialize a database using JPA ....................................................................... 240 76.2. Initialize a database using Hibernate ............................................................... 240 76.3. Initialize a database using Spring JDBC .......................................................... 240 76.4. Initialize a Spring Batch database ................................................................... 241 76.5. Use a higher-level database migration tool ....................................................... 241 Execute Flyway database migrations on startup ................................................ 241 Execute Liquibase database migrations on startup ............................................ 241 77. Batch applications ..................................................................................................... 243 77.1. Execute Spring Batch jobs on startup .............................................................. 243 78. Actuator .................................................................................................................... 244 78.1. Change the HTTP port or address of the actuator endpoints ............................. 244 78.2. Customize the ‘whitelabel’ error page .............................................................. 244 78.3. Actuator and Jersey ........................................................................................ 244 79. Security ..................................................................................................................... 245 79.1. Switch off the Spring Boot security configuration .............................................. 245 79.2. Change the AuthenticationManager and add user accounts .............................. 245 79.3. Enable HTTPS when running behind a proxy server ......................................... 245 80. Hot swapping ............................................................................................................ 247 80.1. Reload static content ...................................................................................... 247 80.2. Reload templates without restarting the container ............................................. 247 Thymeleaf templates ....................................................................................... 247 FreeMarker templates ...................................................................................... 247 Groovy templates ............................................................................................ 247 Velocity templates ........................................................................................... 247 80.3. Fast application restarts .................................................................................. 247 80.4. Reload Java classes without restarting the container ........................................ 247 Configuring Spring Loaded for use with Maven ................................................. 248 Configuring Spring Loaded for use with Gradle and IntelliJ IDEA ........................ 248 81. Build ......................................................................................................................... 249 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot xii 81.1. Generate build information .............................................................................. 249 81.2. Generate git information .................................................................................. 249 81.3. Customize dependency versions ..................................................................... 250 81.4. Create an executable JAR with Maven ............................................................ 250 81.5. Create an additional executable JAR ............................................................... 251 81.6. Extract specific libraries when an executable jar runs ....................................... 251 81.7. Create a non-executable JAR with exclusions .................................................. 252 81.8. Remote debug a Spring Boot application started with Maven ............................. 253 81.9. Remote debug a Spring Boot application started with Gradle ............................. 253 81.10. Build an executable archive from Ant without using spring-boot-antlib ............... 253 81.11. How to use Java 6 ....................................................................................... 254 Embedded servlet container compatibility ......................................................... 254 JTA API compatibility ...................................................................................... 255 82. Traditional deployment ............................................................................................... 256 82.1. Create a deployable war file ........................................................................... 256 82.2. Create a deployable war file for older servlet containers .................................... 257 82.3. Convert an existing application to Spring Boot .................................................. 257 82.4. Deploying a WAR to WebLogic ....................................................................... 258 82.5. Deploying a WAR in an Old (Servlet 2.5) Container .......................................... 259 X. Appendices ......................................................................................................................... 261 A. Common application properties ................................................................................... 262 B. Configuration meta-data .............................................................................................. 282 B.1. Meta-data format .............................................................................................. 282 Group Attributes .............................................................................................. 283 Property Attributes ........................................................................................... 284 Hint Attributes ................................................................................................. 285 Repeated meta-data items ............................................................................... 286 B.2. Providing manual hints ..................................................................................... 286 Value hint ....................................................................................................... 287 Value provider ................................................................................................. 287 Any ......................................................................................................... 288 Class reference ....................................................................................... 288 Handle As ............................................................................................... 289 Logger name .......................................................................................... 290 Spring bean reference ............................................................................. 291 Spring profile name ................................................................................. 291 B.3. Generating your own meta-data using the annotation processor .......................... 292 Nested properties ............................................................................................ 293 Adding additional meta-data ............................................................................ 293 C. Auto-configuration classes ........................................................................................... 294 C.1. From the “spring-boot-autoconfigure” module .................................................... 294 C.2. From the “spring-boot-actuator” module ............................................................ 297 D. The executable jar format ........................................................................................... 298 D.1. Nested JARs ................................................................................................... 298 The executable jar file structure ....................................................................... 298 The executable war file structure ..................................................................... 298 D.2. Spring Boot’s “JarFile” class ............................................................................. 299 Compatibility with the standard Java “JarFile” ................................................... 299 D.3. Launching executable jars ................................................................................ 299 Launcher manifest ........................................................................................... 300 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot xiii Exploded archives ........................................................................................... 300 D.4. PropertiesLauncher Features ............................................................................ 300 D.5. Executable jar restrictions ................................................................................ 301 Zip entry compression ..................................................................................... 301 System ClassLoader ....................................................................................... 301 D.6. Alternative single jar solutions .......................................................................... 302 E. Dependency versions .................................................................................................. 303 Part I. Spring Boot Documentation This section provides a brief overview of Spring Boot reference documentation. Think of it as map for the rest of the document. You can read this reference guide in a linear fashion, or you can skip sections if something doesn’t interest you. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 2 1. About the documentation The Spring Boot reference guide is available as html, pdf and epub documents. The latest copy is available at docs.spring.io/spring-boot/docs/current/reference. Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 3 2. Getting help Having trouble with Spring Boot, We’d like to help! • Try the How-to’s — they provide solutions to the most common questions. • Learn the Spring basics — Spring Boot builds on many other Spring projects, check the spring.io web- site for a wealth of reference documentation. If you are just starting out with Spring, try one of the guides. • Ask a question - we monitor stackoverflow.com for questions tagged with spring-boot. • Report bugs with Spring Boot at github.com/spring-projects/spring-boot/issues. Note All of Spring Boot is open source, including the documentation! If you find problems with the docs; or if you just want to improve them, please get involved. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 4 3. First steps If you’re just getting started with Spring Boot, or 'Spring' in general, this is the place to start! • From scratch: Overview | Requirements | Installation • Tutorial: Part 1 | Part 2 • Running your example: Part 1 | Part 2 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 5 4. Working with Spring Boot Ready to actually start using Spring Boot? We’ve got you covered. • Build systems: Maven | Gradle | Ant | Starters • Best practices: Code Structure | @Configuration | @EnableAutoConfiguration | Beans and Dependency Injection • Running your code IDE | Packaged | Maven | Gradle • Packaging your app: Production jars • Spring Boot CLI: Using the CLI Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 6 5. Learning about Spring Boot features Need more details about Spring Boot’s core features? This is for you! • Core Features: SpringApplication | External Configuration | Profiles | Logging • Web Applications: MVC | Embedded Containers • Working with data: SQL | NO-SQL • Messaging: Overview | JMS • Testing: Overview | Boot Applications | Utils • Extending: Auto-configuration | @Conditions Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 7 6. Moving to production When you’re ready to push your Spring Boot application to production, we’ve got some tricks that you might like! • Management endpoints: Overview | Customization • Connection options: HTTP | JMX | SSH • Monitoring: Metrics | Auditing | Tracing | Process Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 8 7. Advanced topics Lastly, we have a few topics for the more advanced user. • Deploy Spring Boot Applications: Cloud Deployment | OS Service • Build tool plugins: Maven | Gradle • Appendix: Application Properties | Auto-configuration classes | Executable Jars Part II. Getting started If you’re just getting started with Spring Boot, or 'Spring' in general, this is the section for you! Here we answer the basic “what?”, “how?” and “why?” questions. You’ll find a gentle introduction to Spring Boot along with installation instructions. We’ll then build our first Spring Boot application, discussing some core principles as we go. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 10 8. Introducing Spring Boot Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can “just run”. We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration. You can use Spring Boot to create Java applications that can be started using java -jar or more traditional war deployments. We also provide a command line tool that runs “spring scripts”. Our primary goals are: • Provide a radically faster and widely accessible getting started experience for all Spring development. • Be opinionated out of the box, but get out of the way quickly as requirements start to diverge from the defaults. • Provide a range of non-functional features that are common to large classes of projects (e.g. embedded servers, security, metrics, health checks, externalized configuration). • Absolutely no code generation and no requirement for XML configuration. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 11 9. System Requirements By default, Spring Boot 1.4.0.BUILD-SNAPSHOT requires Java 7 and Spring Framework 4.3.0.RELEASE or above. You can use Spring Boot with Java 6 with some additional configuration. See Section 81.11, “How to use Java 6” for more details. Explicit build support is provided for Maven (3.2+) and Gradle (1.12+). Tip Although you can use Spring Boot with Java 6 or 7, we generally recommend Java 8 if at all possible. 9.1 Servlet containers The following embedded servlet containers are supported out of the box: Name Servlet Version Java Version Tomcat 8 3.1 Java 7+ Tomcat 7 3.0 Java 6+ Jetty 9 3.1 Java 7+ Jetty 8 3.0 Java 6+ Undertow 1.1 3.1 Java 7+ You can also deploy Spring Boot applications to any Servlet 3.0+ compatible container. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 12 10. Installing Spring Boot Spring Boot can be used with “classic” Java development tools or installed as a command line tool. Regardless, you will need Java SDK v1.6 or higher. You should check your current Java installation before you begin: $ java -version If you are new to Java development, or if you just want to experiment with Spring Boot you might want to try the Spring Boot CLI first, otherwise, read on for “classic” installation instructions. Tip Although Spring Boot is compatible with Java 1.6, if possible, you should consider using the latest version of Java. 10.1 Installation instructions for the Java developer You can use Spring Boot in the same way as any standard Java library. Simply include the appropriate spring-boot-*.jar files on your classpath. Spring Boot does not require any special tools integration, so you can use any IDE or text editor; and there is nothing special about a Spring Boot application, so you can run and debug as you would any other Java program. Although you could just copy Spring Boot jars, we generally recommend that you use a build tool that supports dependency management (such as Maven or Gradle). Maven installation Spring Boot is compatible with Apache Maven 3.2 or above. If you don’t already have Maven installed you can follow the instructions at maven.apache.org. Tip On many operating systems Maven can be installed via a package manager. If you’re an OSX Homebrew user try brew install maven. Ubuntu users can run sudo apt-get install maven. Spring Boot dependencies use the org.springframework.boot groupId. Typically your Maven POM file will inherit from the spring-boot-starter-parent project and declare dependencies to one or more “Starters”. Spring Boot also provides an optional Maven plugin to create executable jars. Here is a typical pom.xml file: 4.0.0 com.example myproject 0.0.1-SNAPSHOT Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 13 org.springframework.boot spring-boot-starter-parent 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-maven-plugin spring-snapshots http://repo.spring.io/snapshot true spring-milestones http://repo.spring.io/milestone spring-snapshots http://repo.spring.io/snapshot spring-milestones http://repo.spring.io/milestone Tip The spring-boot-starter-parent is a great way to use Spring Boot, but it might not be suitable all of the time. Sometimes you may need to inherit from a different parent POM, or you might just not like our default settings. See the section called “Using Spring Boot without the parent POM” for an alternative solution that uses an import scope. Gradle installation Spring Boot is compatible with Gradle 1.12 or above. If you don’t already have Gradle installed you can follow the instructions at www.gradle.org/. Spring Boot dependencies can be declared using the org.springframework.boot group. Typically your project will declare dependencies to one or more “Starters”. Spring Boot provides a useful Gradle plugin that can be used to simplify dependency declarations and to create executable jars. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 14 Gradle Wrapper The Gradle Wrapper provides a nice way of “obtaining” Gradle when you need to build a project. It’s a small script and library that you commit alongside your code to bootstrap the build process. See www.gradle.org/docs/current/userguide/gradle_wrapper.html for details. Here is a typical build.gradle file: buildscript { repositories { jcenter() maven { url "http://repo.spring.io/snapshot" } maven { url "http://repo.spring.io/milestone" } } dependencies { classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.0.BUILD-SNAPSHOT") } } apply plugin: 'java' apply plugin: 'spring-boot' jar { baseName = 'myproject' version = '0.0.1-SNAPSHOT' } repositories { jcenter() maven { url "http://repo.spring.io/snapshot" } maven { url "http://repo.spring.io/milestone" } } dependencies { compile("org.springframework.boot:spring-boot-starter-web") testCompile("org.springframework.boot:spring-boot-starter-test") } 10.2 Installing the Spring Boot CLI The Spring Boot CLI is a command line tool that can be used if you want to quickly prototype with Spring. It allows you to run Groovy scripts, which means that you have a familiar Java-like syntax, without so much boilerplate code. You don’t need to use the CLI to work with Spring Boot but it’s definitely the quickest way to get a Spring application off the ground. Manual installation You can download the Spring CLI distribution from the Spring software repository: • spring-boot-cli-1.4.0.BUILD-SNAPSHOT-bin.zip • spring-boot-cli-1.4.0.BUILD-SNAPSHOT-bin.tar.gz Cutting edge snapshot distributions are also available. Once downloaded, follow the INSTALL.txt instructions from the unpacked archive. In summary: there is a spring script (spring.bat for Windows) in a bin/ directory in the .zip file, or alternatively you can use java -jar with the .jar file (the script helps you to be sure that the classpath is set correctly). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 15 Installation with SDKMAN! SDKMAN! (The Software Development Kit Manager) can be used for managing multiple versions of various binary SDKs, including Groovy and the Spring Boot CLI. Get SDKMAN! from sdkman.io and install Spring Boot with $ sdk install springboot $ spring --version Spring Boot v1.4.0.BUILD-SNAPSHOT If you are developing features for the CLI and want easy access to the version you just built, follow these extra instructions. $ sdk install springboot dev /path/to/spring-boot/spring-boot-cli/target/spring-boot-cli-1.4.0.BUILD- SNAPSHOT-bin/spring-1.4.0.BUILD-SNAPSHOT/ $ sdk default springboot dev $ spring --version Spring CLI v1.4.0.BUILD-SNAPSHOT This will install a local instance of spring called the dev instance. It points at your target build location, so every time you rebuild Spring Boot, spring will be up-to-date. You can see it by doing this: $ sdk ls springboot ================================================================================ Available Springboot Versions ================================================================================ > + dev * 1.4.0.BUILD-SNAPSHOT ================================================================================ + - local version * - installed > - currently in use ================================================================================ OSX Homebrew installation If you are on a Mac and using Homebrew, all you need to do to install the Spring Boot CLI is: $ brew tap pivotal/tap $ brew install springboot Homebrew will install spring to /usr/local/bin. Note If you don’t see the formula, your installation of brew might be out-of-date. Just execute brew update and try again. MacPorts installation If you are on a Mac and using MacPorts, all you need to do to install the Spring Boot CLI is: $ sudo port install spring-boot-cli Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 16 Command-line completion Spring Boot CLI ships with scripts that provide command completion for BASH and zsh shells. You can source the script (also named spring) in any shell, or put it in your personal or system-wide bash completion initialization. On a Debian system the system-wide scripts are in /shell-completion/ bash and all scripts in that directory are executed when a new shell starts. To run the script manually, e.g. if you have installed using SDKMAN! $ . ~/.sdkman/candidates/springboot/current/shell-completion/bash/spring $ spring grab help jar run test version Note If you install Spring Boot CLI using Homebrew or MacPorts, the command-line completion scripts are automatically registered with your shell. Quick start Spring CLI example Here’s a really simple web application that you can use to test your installation. Create a file called app.groovy: @RestController class ThisWillActuallyRun { @RequestMapping("/") String home() { "Hello World!" } } Then simply run it from a shell: $ spring run app.groovy Note It will take some time when you first run the application as dependencies are downloaded. Subsequent runs will be much quicker. Open localhost:8080 in your favorite web browser and you should see the following output: Hello World! 10.3 Upgrading from an earlier version of Spring Boot If you are upgrading from an earlier release of Spring Boot check the “release notes” hosted on the project wiki. You’ll find upgrade instructions along with a list of “new and noteworthy” features for each release. To upgrade an existing CLI installation use the appropriate package manager command (for example brew upgrade) or, if you manually installed the CLI, follow the standard instructions remembering to update your PATH environment variable to remove any older references. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 17 11. Developing your first Spring Boot application Let’s develop a simple “Hello World!” web application in Java that highlights some of Spring Boot’s key features. We’ll use Maven to build this project since most IDEs support it. Tip The spring.io web site contains many “Getting Started” guides that use Spring Boot. If you’re looking to solve a specific problem; check there first. You can shortcut the steps below by going to start.spring.io and choosing the web starter from the dependencies searcher. This will automatically generate a new project structure so that you can start coding right the way. Check the documentation for more details. Before we begin, open a terminal to check that you have valid versions of Java and Maven installed. $ java -version java version "1.7.0_51" Java(TM) SE Runtime Environment (build 1.7.0_51-b13) Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode) $ mvn -v Apache Maven 3.2.3 (33f8c3e1027c3ddde99d3cdebad2656a31e8fdf4; 2014-08-11T13:58:10-07:00) Maven home: /Users/user/tools/apache-maven-3.1.1 Java version: 1.7.0_51, vendor: Oracle Corporation Note This sample needs to be created in its own folder. Subsequent instructions assume that you have created a suitable folder and that it is your “current directory”. 11.1 Creating the POM We need to start by creating a Maven pom.xml file. The pom.xml is the recipe that will be used to build your project. Open your favorite text editor and add the following: 4.0.0 com.example myproject 0.0.1-SNAPSHOT org.springframework.boot spring-boot-starter-parent 1.4.0.BUILD-SNAPSHOT spring-snapshots http://repo.spring.io/snapshot true Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 18 spring-milestones http://repo.spring.io/milestone spring-snapshots http://repo.spring.io/snapshot spring-milestones http://repo.spring.io/milestone This should give you a working build, you can test it out by running mvn package (you can ignore the “jar will be empty - no content was marked for inclusion!” warning for now). Note At this point you could import the project into an IDE (most modern Java IDE’s include built-in support for Maven). For simplicity, we will continue to use a plain text editor for this example. 11.2 Adding classpath dependencies Spring Boot provides a number of “Starters” that make easy to add jars to your classpath. Our sample application has already used spring-boot-starter-parent in the parent section of the POM. The spring-boot-starter-parent is a special starter that provides useful Maven defaults. It also provides a dependency-management section so that you can omit version tags for “blessed” dependencies. Other “Starters” simply provide dependencies that you are likely to need when developing a specific type of application. Since we are developing a web application, we will add a spring-boot-starter- web dependency — but before that, let’s look at what we currently have. $ mvn dependency:tree [INFO] com.example:myproject:jar:0.0.1-SNAPSHOT The mvn dependency:tree command prints a tree representation of your project dependencies. You can see that spring-boot-starter-parent provides no dependencies by itself. Let’s edit our pom.xml and add the spring-boot-starter-web dependency just below the parent section: org.springframework.boot spring-boot-starter-web If you run mvn dependency:tree again, you will see that there are now a number of additional dependencies, including the Tomcat web server and Spring Boot itself. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 19 11.3 Writing the code To finish our application we need to create a single Java file. Maven will compile sources from src/ main/java by default so you need to create that folder structure, then add a file named src/main/ java/Example.java: import org.springframework.boot.*; import org.springframework.boot.autoconfigure.*; import org.springframework.stereotype.*; import org.springframework.web.bind.annotation.*; @RestController @EnableAutoConfiguration public class Example { @RequestMapping("/") String home() { return "Hello World!"; } public static void main(String[] args) throws Exception { SpringApplication.run(Example.class, args); } } Although there isn’t much code here, quite a lot is going on. Let’s step through the important parts. The @RestController and @RequestMapping annotations The first annotation on our Example class is @RestController. This is known as a stereotype annotation. It provides hints for people reading the code, and for Spring, that the class plays a specific role. In this case, our class is a web @Controller so Spring will consider it when handling incoming web requests. The @RequestMapping annotation provides “routing” information. It is telling Spring that any HTTP request with the path “/” should be mapped to the home method. The @RestController annotation tells Spring to render the resulting string directly back to the caller. Tip The @RestController and @RequestMapping annotations are Spring MVC annotations (they are not specific to Spring Boot). See the MVC section in the Spring Reference Documentation for more details. The @EnableAutoConfiguration annotation The second class-level annotation is @EnableAutoConfiguration. This annotation tells Spring Boot to “guess” how you will want to configure Spring, based on the jar dependencies that you have added. Since spring-boot-starter-web added Tomcat and Spring MVC, the auto-configuration will assume that you are developing a web application and setup Spring accordingly. Starters and Auto-Configuration Auto-configuration is designed to work well with “Starters”, but the two concepts are not directly tied. You are free to pick-and-choose jar dependencies outside of the starters and Spring Boot will still do its best to auto-configure your application. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 20 The “main” method The final part of our application is the main method. This is just a standard method that follows the Java convention for an application entry point. Our main method delegates to Spring Boot’s SpringApplication class by calling run. SpringApplication will bootstrap our application, starting Spring which will in turn start the auto-configured Tomcat web server. We need to pass Example.class as an argument to the run method to tell SpringApplication which is the primary Spring component. The args array is also passed through to expose any command-line arguments. 11.4 Running the example At this point our application should work. Since we have used the spring-boot-starter-parent POM we have a useful run goal that we can use to start the application. Type mvn spring-boot:run from the root project directory to start the application: $ mvn spring-boot:run . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.4.0.BUILD-SNAPSHOT) ....... . . . ....... . . . (log output here) ....... . . . ........ Started Example in 2.222 seconds (JVM running for 6.514) If you open a web browser to localhost:8080 you should see the following output: Hello World! To gracefully exit the application hit ctrl-c. 11.5 Creating an executable jar Let’s finish our example by creating a completely self-contained executable jar file that we could run in production. Executable jars (sometimes called “fat jars”) are archives containing your compiled classes along with all of the jar dependencies that your code needs to run. Executable jars and Java Java does not provide any standard way to load nested jar files (i.e. jar files that are themselves contained within a jar). This can be problematic if you are looking to distribute a self-contained application. To solve this problem, many developers use “uber” jars. An uber jar simply packages all classes, from all jars, into a single archive. The problem with this approach is that it becomes hard to see which libraries you are actually using in your application. It can also be problematic if the same filename is used (but with different content) in multiple jars. Spring Boot takes a different approach and allows you to actually nest jars directly. To create an executable jar we need to add the spring-boot-maven-plugin to our pom.xml. Insert the following lines just below the dependencies section: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 21 org.springframework.boot spring-boot-maven-plugin Note The spring-boot-starter-parent POM includes configuration to bind the repackage goal. If you are not using the parent POM you will need to declare this configuration yourself. See the plugin documentation for details. Save your pom.xml and run mvn package from the command line: $ mvn package [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building myproject 0.0.1-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] .... .. [INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ myproject --- [INFO] Building jar: /Users/developer/example/spring-boot-example/target/myproject-0.0.1-SNAPSHOT.jar [INFO] [INFO] --- spring-boot-maven-plugin:1.4.0.BUILD-SNAPSHOT:repackage (default) @ myproject --- [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ If you look in the target directory you should see myproject-0.0.1-SNAPSHOT.jar. The file should be around 10 Mb in size. If you want to peek inside, you can use jar tvf: $ jar tvf target/myproject-0.0.1-SNAPSHOT.jar You should also see a much smaller file named myproject-0.0.1-SNAPSHOT.jar.original in the target directory. This is the original jar file that Maven created before it was repackaged by Spring Boot. To run that application, use the java -jar command: $ java -jar target/myproject-0.0.1-SNAPSHOT.jar . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.4.0.BUILD-SNAPSHOT) ....... . . . ....... . . . (log output here) ....... . . . ........ Started Example in 2.536 seconds (JVM running for 2.864) As before, to gracefully exit the application hit ctrl-c. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 22 12. What to read next Hopefully this section has provided you with some of the Spring Boot basics, and got you on your way to writing your own applications. If you’re a task-oriented type of developer you might want to jump over to spring.io and check out some of the getting started guides that solve specific “How do I do that with Spring” problems; we also have Spring Boot-specific How-to reference documentation. The Spring Boot repository has also a bunch of samples you can run. The samples are independent of the rest of the code (that is you don’t need to build the rest to run or use the samples). Otherwise, the next logical step is to read Part III, “Using Spring Boot”. If you’re really impatient, you could also jump ahead and read about Spring Boot features. Part III. Using Spring Boot This section goes into more detail about how you should use Spring Boot. It covers topics such as build systems, auto-configuration and how to run your applications. We also cover some Spring Boot best practices. Although there is nothing particularly special about Spring Boot (it is just another library that you can consume), there are a few recommendations that, when followed, will make your development process just a little easier. If you’re just starting out with Spring Boot, you should probably read the Getting Started guide before diving into this section. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 24 13. Build systems It is strongly recommended that you choose a build system that supports dependency management, and one that can consume artifacts published to the “Maven Central” repository. We would recommend that you choose Maven or Gradle. It is possible to get Spring Boot to work with other build systems (Ant for example), but they will not be particularly well supported. 13.1 Dependency management Each release of Spring Boot provides a curated list of dependencies it supports. In practice, you do not need to provide a version for any of these dependencies in your build configuration as Spring Boot is managing that for you. When you upgrade Spring Boot itself, these dependencies will be upgraded as well in a consistent way. Note You can still specify a version and override Spring Boot’s recommendations if you feel that’s necessary. The curated list contains all the spring modules that you can use with Spring Boot as well as a refined list of third party libraries. The list is available as a standard Bills of Materials (spring-boot- dependencies) and additional dedicated support for Maven and Gradle are available as well. Warning Each release of Spring Boot is associated with a base version of the Spring Framework so we highly recommend you to not specify its version on your own. 13.2 Maven Maven users can inherit from the spring-boot-starter-parent project to obtain sensible defaults. The parent project provides the following features: • Java 1.6 as the default compiler level. • UTF-8 source encoding. • A Dependency Management section, allowing you to omit tags for common dependencies, inherited from the spring-boot-dependencies POM. • Sensible resource filtering. • Sensible plugin configuration (exec plugin, surefire, Git commit ID, shade). • Sensible resource filtering for application.properties and application.yml including profile-specific files (e.g. application-foo.properties and application-foo.yml) On the last point: since the default config files accept Spring style placeholders (${…}) the Maven filtering is changed to use @..@ placeholders (you can override that with a Maven property resource.delimiter). Inheriting the starter parent To configure your project to inherit from the spring-boot-starter-parent simply set the parent: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 25 org.springframework.boot spring-boot-starter-parent 1.4.0.BUILD-SNAPSHOT Note You should only need to specify the Spring Boot version number on this dependency. If you import additional starters, you can safely omit the version number. With that setup, you can also override individual dependencies by overriding a property in your own project. For instance, to upgrade to another Spring Data release train you’d add the following to your pom.xml. Fowler-SR2 Tip Check the spring-boot-dependencies pom for a list of supported properties. Using Spring Boot without the parent POM Not everyone likes inheriting from the spring-boot-starter-parent POM. You may have your own corporate standard parent that you need to use, or you may just prefer to explicitly declare all your Maven configuration. If you don’t want to use the spring-boot-starter-parent, you can still keep the benefit of the dependency management (but not the plugin management) by using a scope=import dependency: org.springframework.boot spring-boot-dependencies 1.4.0.BUILD-SNAPSHOT pom import That setup does not allow you to override individual dependencies using a property as explained above. To achieve the same result, you’d need to add an entry in the dependencyManagement of your project before the spring-boot-dependencies entry. For instance, to upgrade to another Spring Data release train you’d add the following to your pom.xml. org.springframework.data spring-data-releasetrain Fowler-SR2 import Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 26 pom org.springframework.boot spring-boot-dependencies 1.4.0.BUILD-SNAPSHOT pom import Note In the example above, we specify a BOM but any dependency type can be overridden that way. Changing the Java version The spring-boot-starter-parent chooses fairly conservative Java compatibility. If you want to follow our recommendation and use a later Java version you can add a java.version property: 1.8 Using the Spring Boot Maven plugin Spring Boot includes a Maven plugin that can package the project as an executable jar. Add the plugin to your section if you want to use it: org.springframework.boot spring-boot-maven-plugin Note If you use the Spring Boot starter parent pom, you only need to add the plugin, there is no need for to configure it unless you want to change the settings defined in the parent. 13.3 Gradle Gradle users can directly import ‘starters’ in their dependencies section. Unlike Maven, there is no “super parent” to import to share some configuration. apply plugin: 'java' repositories { maven { url "http://repo.spring.io/snapshot" } maven { url "http://repo.spring.io/milestone" } } dependencies { compile("org.springframework.boot:spring-boot-starter-web:1.4.0.BUILD-SNAPSHOT") } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 27 The spring-boot-gradle-plugin is also available and provides tasks to create executable jars and run projects from source. It also provides dependency management that, among other capabilities, allows you to omit the version number for any dependencies that are managed by Spring Boot: buildscript { repositories { maven { url "http://repo.spring.io/snapshot" } maven { url "http://repo.spring.io/milestone" } } dependencies { classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.0.BUILD-SNAPSHOT") } } apply plugin: 'java' apply plugin: 'spring-boot' repositories { maven { url "http://repo.spring.io/snapshot" } maven { url "http://repo.spring.io/milestone" } } dependencies { compile("org.springframework.boot:spring-boot-starter-web") testCompile("org.springframework.boot:spring-boot-starter-test") } 13.4 Ant It is possible to build a Spring Boot project using Apache Ant+Ivy. The spring-boot-antlib “AntLib” module is also available to help Ant create executable jars. To declare dependencies a typical ivy.xml file will look something like this: A typical build.xml will look like this: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 28 Tip See the Section 81.10, “Build an executable archive from Ant without using spring-boot-antlib” “How-to” if you don’t want to use the spring-boot-antlib module. 13.5 Starters Starters are a set of convenient dependency descriptors that you can include in your application. You get a one-stop-shop for all the Spring and related technology that you need, without having to hunt through sample code and copy paste loads of dependency descriptors. For example, if you want to get started using Spring and JPA for database access, just include the spring-boot-starter-data- jpa dependency in your project, and you are good to go. The starters contain a lot of the dependencies that you need to get a project up and running quickly and with a consistent, supported set of managed transitive dependencies. What’s in a name All official starters follow a similar naming pattern; spring-boot-starter-*, where * is a particular type of application. This naming structure is intended to help when you need to find a starter. The Maven integration in many IDEs allow you to search dependencies by name. For example, with the appropriate Eclipse or STS plugin installed, you can simply hit ctrl-space in the POM editor and type “spring-boot-starter” for a complete list. As explained in the Creating your own starter section, third party starters should not start with spring-boot as it is reserved for official Spring Boot artifacts. A third-party starter for acme will be typically named acme-spring-boot-starter. The following application starters are provided by Spring Boot under the org.springframework.boot group: Table 13.1. Spring Boot application starters Name Description Pom spring-boot-starter- test Starter for testing Spring Boot applications with libraries including JUnit, Hamcrest and Mockito Pom Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 29 Name Description Pom spring-boot-starter- mobile Starter for building web applications using Spring Mobile Pom spring-boot-starter- social-twitter Starter for using Spring Social Twitter Pom spring-boot-starter- cache Starter for using Spring Framework’s caching support Pom spring-boot-starter- activemq Starter for JMS messaging using Apache ActiveMQ Pom spring-boot-starter- jta-atomikos Starter for JTA transactions using Atomikos Pom spring-boot-starter-aop Starter for aspect-oriented programming with Spring AOP and AspectJ Pom spring-boot-starter-web Starter for building web, including RESTful, applications using Spring MVC. Uses Tomcat as the default embedded container Pom spring-boot-starter- data-elasticsearch Starter for using Elasticsearch search and analytics engine and Spring Data Elasticsearch Pom spring-boot-starter- jdbc Starter for using JDBC with the Tomcat JDBC connection pool Pom spring-boot-starter- batch Starter for using Spring Batch, including HSQLDB in-memory database Pom spring-boot-starter- social-facebook Starter for using Spring Social Facebook Pom spring-boot-starter- web-services Starter for using Spring Web Services Pom spring-boot-starter- jta-narayana Spring Boot Narayana JTA Starter Pom spring-boot-starter- thymeleaf Starter for building MVC web applications using Thymeleaf views Pom spring-boot-starter- mail Starter for using Java Mail and Spring Framework’s email sending support Pom Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 30 Name Description Pom spring-boot-starter- jta-bitronix Starter for JTA transactions using Bitronix Pom spring-boot-starter- data-mongodb Starter for using MongoDB document-oriented database and Spring Data MongoDB Pom spring-boot-starter- validation Starter for using Java Bean Validation with Hibernate Validator Pom spring-boot-starter- jooq Starter for using jOOQ to access SQL databases. An alternative to spring-boot- starter-data-jpa or spring-boot-starter- jdbc Pom spring-boot-starter- redis Starter for using Redis key- value data store with Spring Data Redis and the Jedis client. Deprecated as of 1.4 in favor of spring-boot-starter- data-redis Pom spring-boot-starter- data-cassandra Starter for using Cassandra distributed database and Spring Data Cassandra Pom spring-boot-starter- hateoas Starter for building hypermedia- based RESTful web application with Spring MVC and Spring HATEOAS Pom spring-boot-starter- integration Starter for using Spring Integration Pom spring-boot-starter- data-solr Starter for using the Apache Solr search platform with Spring Data Solr Pom spring-boot-starter- freemarker Starter for building MVC web applications using Freemarker views Pom spring-boot-starter- jersey Starter for building RESTful web applications using JAX-RS and Jersey. An alternative to spring-boot-starter-web Pom Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 31 Name Description Pom spring-boot-starter Core starter, including auto- configuration support, logging and YAML Pom spring-boot-starter- data-couchbase Starter for using Couchbase document-oriented database and Spring Data Couchbase Pom spring-boot-starter- artemis Starter for JMS messaging using Apache Artemis Pom spring-boot-starter- cloud-connectors Starter for using Spring Cloud Connectors which simplifies connecting to services in cloud platforms like Cloud Foundry and Heroku Pom spring-boot-starter- social-linkedin Stater for using Spring Social LinkedIn Pom spring-boot-starter- velocity Starter for building MVC web applications using Velocity views. Deprecated since 1.4 Pom spring-boot-starter- data-rest Starter for exposing Spring Data repositories over REST using Spring Data REST Pom spring-boot-starter- data-gemfire Starter for using GemFire distributed data store and Spring Data GemFire Pom spring-boot-starter- groovy-templates Starter for building MVC web applications using Groovy Templates views Pom spring-boot-starter- amqp Starter for using Spring AMQP and Rabbit MQ Pom spring-boot-starter- hornetq Starter for JMS messaging using HornetQ. Deprecated as of 1.4 in favor of spring- boot-starter-artemis Pom spring-boot-starter-ws Starter for using Spring Web Services. Deprecated as of 1.4 in favor of spring-boot- starter-web-services Pom spring-boot-starter- security Starter for using Spring Security Pom Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 32 Name Description Pom spring-boot-starter- data-redis Starter for using Redis key- value data store with Spring Data Redis and the Jedis client Pom spring-boot-starter- websocket Starter for building WebSocket applications using Spring Framework’s WebSocket support Pom spring-boot-starter- mustache Starter for building MVC web applications using Mustache views Pom spring-boot-starter- data-neo4j Starter for using Neo4j graph database and Spring Data Neo4j Pom spring-boot-starter- data-jpa Starter for using Spring Data JPA with Hibernate Pom In addition to the application starters, the following starters can be used to add production ready features: Table 13.2. Spring Boot production starters Name Description Pom spring-boot-starter- actuator Starter for using Spring Boot’s Actuator which provides production ready features to help you monitor and manage your application Pom spring-boot-starter- remote-shell Starter for using the CRaSH remote shell to monitor and manage your application over SSH Pom Finally, Spring Boot also includes some starters that can be used if you want to exclude or swap specific technical facets: Table 13.3. Spring Boot technical starters Name Description Pom spring-boot-starter- undertow Starter for using Undertow as the embedded servlet container. An alternative to spring-boot-starter- tomcat Pom spring-boot-starter- logging Starter for logging using Logback. Default logging starter Pom Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 33 Name Description Pom spring-boot-starter- tomcat Starter for using Tomcat as the embedded servlet container. Default servlet container starter used by spring-boot- starter-web Pom spring-boot-starter- jetty Starter for using Jetty as the embedded servlet container. An alternative to spring-boot- starter-tomcat Pom spring-boot-starter- log4j2 Starter for using Log4j2 for logging. An alternative to spring-boot-starter- logging Pom Tip For a list of additional community contributed starters, see the README file in the spring-boot- starters module on GitHub. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 34 14. Structuring your code Spring Boot does not require any specific code layout to work, however, there are some best practices that help. 14.1 Using the “default” package When a class doesn’t include a package declaration it is considered to be in the “default package”. The use of the “default package” is generally discouraged, and should be avoided. It can cause particular problems for Spring Boot applications that use @ComponentScan, @EntityScan or @SpringBootApplication annotations, since every class from every jar, will be read. Tip We recommend that you follow Java’s recommended package naming conventions and use a reversed domain name (for example, com.example.project). 14.2 Locating the main application class We generally recommend that you locate your main application class in a root package above other classes. The @EnableAutoConfiguration annotation is often placed on your main class, and it implicitly defines a base “search package” for certain items. For example, if you are writing a JPA application, the package of the @EnableAutoConfiguration annotated class will be used to search for @Entity items. Using a root package also allows the @ComponentScan annotation to be used without needing to specify a basePackage attribute. You can also use the @SpringBootApplication annotation if your main class is in the root package. Here is a typical layout: com +- example +- myproject +- Application.java | +- domain | +- Customer.java | +- CustomerRepository.java | +- service | +- CustomerService.java | +- web +- CustomerController.java The Application.java file would declare the main method, along with the basic @Configuration. package com.example.myproject; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; @Configuration @EnableAutoConfiguration @ComponentScan Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 35 public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 36 15. Configuration classes Spring Boot favors Java-based configuration. Although it is possible to call SpringApplication.run() with an XML source, we generally recommend that your primary source is a @Configuration class. Usually the class that defines the main method is also a good candidate as the primary @Configuration. Tip Many Spring configuration examples have been published on the Internet that use XML configuration. Always try to use the equivalent Java-based configuration if possible. Searching for enable* annotations can be a good starting point. 15.1 Importing additional configuration classes You don’t need to put all your @Configuration into a single class. The @Import annotation can be used to import additional configuration classes. Alternatively, you can use @ComponentScan to automatically pick up all Spring components, including @Configuration classes. 15.2 Importing XML configuration If you absolutely must use XML based configuration, we recommend that you still start with a @Configuration class. You can then use an additional @ImportResource annotation to load XML configuration files. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 37 16. Auto-configuration Spring Boot auto-configuration attempts to automatically configure your Spring application based on the jar dependencies that you have added. For example, If HSQLDB is on your classpath, and you have not manually configured any database connection beans, then we will auto-configure an in-memory database. You need to opt-in to auto-configuration by adding the @EnableAutoConfiguration or @SpringBootApplication annotations to one of your @Configuration classes. Tip You should only ever add one @EnableAutoConfiguration annotation. We generally recommend that you add it to your primary @Configuration class. 16.1 Gradually replacing auto-configuration Auto-configuration is noninvasive, at any point you can start to define your own configuration to replace specific parts of the auto-configuration. For example, if you add your own DataSource bean, the default embedded database support will back away. If you need to find out what auto-configuration is currently being applied, and why, start your application with the --debug switch. This will enable debug logs for a selection of core loggers and log an auto- configuration report to the console. 16.2 Disabling specific auto-configuration If you find that specific auto-configure classes are being applied that you don’t want, you can use the exclude attribute of @EnableAutoConfiguration to disable them. import org.springframework.boot.autoconfigure.*; import org.springframework.boot.autoconfigure.jdbc.*; import org.springframework.context.annotation.*; @Configuration @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class}) public class MyConfiguration { } If the class is not on the classpath, you can use the excludeName attribute of the annotation and specify the fully qualified name instead. Finally, you can also control the list of auto-configuration classes to exclude via the spring.autoconfigure.exclude property. Tip You can define exclusions both at the annotation level and using the property. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 38 17. Spring Beans and dependency injection You are free to use any of the standard Spring Framework techniques to define your beans and their injected dependencies. For simplicity, we often find that using @ComponentScan to find your beans, in combination with @Autowired constructor injection works well. If you structure your code as suggested above (locating your application class in a root package), you can add @ComponentScan without any arguments. All of your application components (@Component, @Service, @Repository, @Controller etc.) will be automatically registered as Spring Beans. Here is an example @Service Bean that uses constructor injection to obtain a required RiskAssessor bean. package com.example.service; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @Service public class DatabaseAccountService implements AccountService { private final RiskAssessor riskAssessor; @Autowired public DatabaseAccountService(RiskAssessor riskAssessor) { this.riskAssessor = riskAssessor; } // ... } Tip Notice how using constructor injection allows the riskAssessor field to be marked as final, indicating that it cannot be subsequently changed. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 39 18. Using the @SpringBootApplication annotation Many Spring Boot developers always have their main class annotated with @Configuration, @EnableAutoConfiguration and @ComponentScan. Since these annotations are so frequently used together (especially if you follow the best practices above), Spring Boot provides a convenient @SpringBootApplication alternative. The @SpringBootApplication annotation is equivalent to using @Configuration, @EnableAutoConfiguration and @ComponentScan with their default attributes: package com.example.myproject; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication // same as @Configuration @EnableAutoConfiguration @ComponentScan public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } } Note @SpringBootApplication also provides aliases to customize the attributes of @EnableAutoConfiguration and @ComponentScan. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 40 19. Running your application One of the biggest advantages of packaging your application as jar and using an embedded HTTP server is that you can run your application as you would any other. Debugging Spring Boot applications is also easy; you don’t need any special IDE plugins or extensions. Note This section only covers jar based packaging, If you choose to package your application as a war file you should refer to your server and IDE documentation. 19.1 Running from an IDE You can run a Spring Boot application from your IDE as a simple Java application, however, first you will need to import your project. Import steps will vary depending on your IDE and build system. Most IDEs can import Maven projects directly, for example Eclipse users can select Import… → Existing Maven Projects from the File menu. If you can’t directly import your project into your IDE, you may be able to generate IDE metadata using a build plugin. Maven includes plugins for Eclipse and IDEA; Gradle offers plugins for various IDEs. Tip If you accidentally run a web application twice you will see a “Port already in use” error. STS users can use the Relaunch button rather than Run to ensure that any existing instance is closed. 19.2 Running as a packaged application If you use the Spring Boot Maven or Gradle plugins to create an executable jar you can run your application using java -jar. For example: $ java -jar target/myproject-0.0.1-SNAPSHOT.jar It is also possible to run a packaged application with remote debugging support enabled. This allows you to attach a debugger to your packaged application: $ java -Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=8000,suspend=n \ -jar target/myproject-0.0.1-SNAPSHOT.jar 19.3 Using the Maven plugin The Spring Boot Maven plugin includes a run goal which can be used to quickly compile and run your application. Applications run in an exploded form just like in your IDE. $ mvn spring-boot:run You might also want to use the useful operating system environment variable: $ export MAVEN_OPTS=-Xmx1024m -XX:MaxPermSize=128M -Djava.security.egd=file:/dev/./urandom (The “egd” setting is to speed up Tomcat startup by giving it a faster source of entropy for session keys.) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 41 19.4 Using the Gradle plugin The Spring Boot Gradle plugin also includes a bootRun task which can be used to run your application in an exploded form. The bootRun task is added whenever you import the spring-boot-gradle- plugin: $ gradle bootRun You might also want to use this useful operating system environment variable: $ export JAVA_OPTS=-Xmx1024m -XX:MaxPermSize=128M -Djava.security.egd=file:/dev/./urandom 19.5 Hot swapping Since Spring Boot applications are just plain Java applications, JVM hot-swapping should work out of the box. JVM hot swapping is somewhat limited with the bytecode that it can replace, for a more complete solution JRebel or the Spring Loaded project can be used. The spring-boot-devtools module also includes support for quick application restarts. See the Chapter 20, Developer tools section below and the Hot swapping “How-to” for details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 42 20. Developer tools Spring Boot includes an additional set of tools that can make the application development experience a little more pleasant. The spring-boot-devtools module can be included in any project to provide additional development-time features. To include devtools support, simply add the module dependency to your build: Maven. org.springframework.boot spring-boot-devtools true Gradle. dependencies { compile("org.springframework.boot:spring-boot-devtools") } Note Developer tools are automatically disabled when running a fully packaged application. If your application is launched using java -jar or if it’s started using a special classloader, then it is considered a “production application”. Flagging the dependency as optional is a best practice that prevents devtools from being transitively applied to other modules using your project. Gradle does not support optional dependencies out-of-the-box so you may want to have a look to the propdeps-plugin in the meantime. Tip If you want to ensure that devtools is never included in a production build, you can use the excludeDevtools build property to completely remove the JAR. The property is supported with both the Maven and Gradle plugins. 20.1 Property defaults Several of the libraries supported by Spring Boot use caches to improve performance. For example, Thymeleaf will cache templates to save repeatedly parsing XML source files. Whilst caching is very beneficial in production, it can be counter productive during development. If you make a change to a template file in your IDE, you’ll likely want to immediately see the result. Cache options are usually configured by settings in your application.properties file. For example, Thymeleaf offers the spring.thymeleaf.cache property. Rather than needing to set these properties manually, the spring-boot-devtools module will automatically apply sensible development-time configuration. Tip For a complete list of the properties that are applied see DevToolsPropertyDefaultsPostProcessor. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 43 20.2 Automatic restart Applications that use spring-boot-devtools will automatically restart whenever files on the classpath change. This can be a useful feature when working in an IDE as it gives a very fast feedback loop for code changes. By default, any entry on the classpath that points to a folder will be monitored for changes. Note that certain resources such as static assets and view templates do not need to restart the application. Triggering a restart As DevTools monitors classpath resources, the only way to trigger a restart is to update the classpath. The way in which you cause the classpath to be updated depends on the IDE that you are using. In Eclipse, saving a modified file will cause the classpath to be updated and trigger a restart. In IntelliJ IDEA, building the project (Build # Make Project) will have the same effect. Note You can also start your application via the supported build plugins (i.e. Maven and Gradle) as long as forking is enabled since DevTools need an isolated application classloader to operate properly. You can force the plugin to fork the process as follows: Maven. org.springframework.boot spring-boot-maven-plugin true Gradle. bootRun { addResources = true } Tip Automatic restart works very well when used with LiveReload. See below for details. If you use JRebel automatic restarts will be disabled in favor of dynamic class reloading. Other devtools features (such as LiveReload and property overrides) can still be used. Note DevTools relies on the application context’s shutdown hook to close it during a restart. It will not work correctly if you have disabled the shutdown hook ( SpringApplication.setRegisterShutdownHook(false)). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 44 Note When deciding if an entry on the classpath should trigger a restart when it changes, DevTools automatically ignores projects named spring-boot, spring-boot-devtools, spring- boot-autoconfigure, spring-boot-actuator, and spring-boot-starter. Restart vs Reload The restart technology provided by Spring Boot works by using two classloaders. Classes that don’t change (for example, those from third-party jars) are loaded into a base classloader. Classes that you’re actively developing are loaded into a restart classloader. When the application is restarted, the restart classloader is thrown away and a new one is created. This approach means that application restarts are typically much faster than “cold starts” since the base classloader is already available and populated. If you find that restarts aren’t quick enough for your applications, or you encounter classloading issues, you could consider reloading technologies such as JRebel from ZeroTurnaround. These work by rewriting classes as they are loaded to make them more amenable to reloading. Spring Loaded provides another option, however it doesn’t support as many frameworks and it isn’t commercially supported. Excluding resources Certain resources don’t necessarily need to trigger a restart when they are changed. For example, Thymeleaf templates can just be edited in-place. By default changing resources in /META-INF/ maven, /META-INF/resources ,/resources ,/static ,/public or /templates will not trigger a restart but will trigger a live reload. If you want to customize these exclusions you can use the spring.devtools.restart.exclude property. For example, to exclude only /static and / public you would set the following: spring.devtools.restart.exclude=static/**,public/** Tip if you want to keep those defaults and add additional exclusions, use the spring.devtools.restart.additional-exclude property instead. Watching additional paths You may want your application to be restarted or reloaded when you make changes to files that are not on the classpath. To do so, use the spring.devtools.restart.additional- paths property to configure additional paths to watch for changes. You can use the spring.devtools.restart.exclude property described above to control whether changes beneath the additional paths will trigger a full restart or just a live reload. Disabling restart If you don’t want to use the restart feature you can disable it using the spring.devtools.restart.enabled property. In most cases you can set this in your application.properties (this will still initialize the restart classloader but it won’t watch for file changes). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 45 If you need to completely disable restart support, for example, because it doesn’t work with a specific library, you need to set a System property before calling SpringApplication.run(…). For example: public static void main(String[] args) { System.setProperty("spring.devtools.restart.enabled", "false"); SpringApplication.run(MyApp.class, args); } Using a trigger file If you work with an IDE that continuously compiles changed files, you might prefer to trigger restarts only at specific times. To do this you can use a “trigger file”, which is a special file that must be modified when you want to actually trigger a restart check. The trigger file could be updated manually, or via an IDE plugin. To use a trigger file use the spring.devtools.restart.trigger-file property. Tip You might want to set spring.devtools.restart.trigger-file as a global setting so that all your projects behave in the same way. Customizing the restart classloader As described in the Restart vs Reload section above, restart functionality is implemented by using two classloaders. For most applications this approach works well, however, sometimes it can cause classloading issues. By default, any open project in your IDE will be loaded using the “restart” classloader, and any regular .jar file will be loaded using the “base” classloader. If you work on a multi-module project, and not each module is imported into your IDE, you may need to customize things. To do this you can create a META-INF/spring-devtools.properties file. The spring-devtools.properties file can contain restart.exclude. and restart.include. prefixed properties. The include elements are items that should be pulled up into the “restart” classloader, and the exclude elements are items that should be pushed down into the “base” classloader. The value of the property is a regex pattern that will be applied to the classpath. For example: restart.include.companycommonlibs=/mycorp-common-[\\w-]+\.jar restart.include.projectcommon=/mycorp-myproj-[\\w-]+\.jar Note All property keys must be unique. As long as a property starts with restart.include. or restart.exclude. it will be considered. Tip All META-INF/spring-devtools.properties from the classpath will be loaded. You can package files inside your project, or in the libraries that the project consumes. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 46 Known limitations Restart functionality does not work well with objects that are deserialized using a standard ObjectInputStream. If you need to deserialize data, you may need to use Spring’s ConfigurableObjectInputStream in combination with Thread.currentThread().getContextClassLoader(). Unfortunately, several third-party libraries deserialize without considering the context classloader. If you find such a problem, you will need to request a fix with the original authors. 20.3 LiveReload The spring-boot-devtools module includes an embedded LiveReload server that can be used to trigger a browser refresh when a resource is changed. LiveReload browser extensions are freely available for Chrome, Firefox and Safari from livereload.com. If you don’t want to start the LiveReload server when your application runs you can set the spring.devtools.livereload.enabled property to false. Note You can only run one LiveReload server at a time, if you start multiple applications from your IDE only the first will have livereload support. 20.4 Global settings You can configure global devtools settings by adding a file named .spring-boot- devtools.properties to your $HOME folder (note that the filename starts with “.”). Any properties added to this file will apply to all Spring Boot applications on your machine that use devtools. For example, to configure restart to always use a trigger file, you would add the following: ~/.spring-boot-devtools.properties. spring.devtools.reload.trigger-file=.reloadtrigger 20.5 Remote applications The Spring Boot developer tools are not just limited to local development. You can also use several features when running applications remotely. Remote support is opt-in, to enable it you need to set a spring.devtools.remote.secret property. For example: spring.devtools.remote.secret=mysecret Warning Enabling spring-boot-devtools on a remote application is a security risk. You should never enable support on a production deployment. Remote devtools support is provided in two parts; there is a server side endpoint that accepts connections, and a client application that you run in your IDE. The server component is automatically enabled when the spring.devtools.remote.secret property is set. The client component must be launched manually. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 47 Running the remote client application The remote client application is designed to be run from within you IDE. You need to run org.springframework.boot.devtools.RemoteSpringApplication using the same classpath as the remote project that you’re connecting to. The non-option argument passed to the application should be the remote URL that you are connecting to. For example, if you are using Eclipse or STS, and you have a project named my-app that you’ve deployed to Cloud Foundry, you would do the following: • Select Run Configurations… from the Run menu. • Create a new Java Application “launch configuration”. • Browse for the my-app project. • Use org.springframework.boot.devtools.RemoteSpringApplication as the main class. • Add https://myapp.cfapps.io to the Program arguments (or whatever your remote URL is). A running remote client will look like this: . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ ___ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | | _ \___ _ __ ___| |_ ___ \ \ \ \ \\/ ___)| |_)| | | | | || (_| []::::::[] / -_) ' \/ _ \ _/ -_) ) ) ) ) ' |____| .__|_| |_|_| |_\__, | |_|_\___|_|_|_\___/\__\___|/ / / / =========|_|==============|___/===================================/_/_/_/ :: Spring Boot Remote :: 1.4.0.BUILD-SNAPSHOT 2015-06-10 18:25:06.632 INFO 14938 --- [ main] o.s.b.devtools.RemoteSpringApplication : Starting RemoteSpringApplication on pwmbp with PID 14938 (/Users/pwebb/projects/spring-boot/code/ spring-boot-devtools/target/classes started by pwebb in /Users/pwebb/projects/spring-boot/code/spring- boot-samples/spring-boot-sample-devtools) 2015-06-10 18:25:06.671 INFO 14938 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@2a17b7b6: startup date [Wed Jun 10 18:25:06 PDT 2015]; root of context hierarchy 2015-06-10 18:25:07.043 WARN 14938 --- [ main] o.s.b.d.r.c.RemoteClientConfiguration : The connection to http://localhost:8080 is insecure. You should use a URL starting with 'https://'. 2015-06-10 18:25:07.074 INFO 14938 --- [ main] o.s.b.d.a.OptionalLiveReloadServer : LiveReload server is running on port 35729 2015-06-10 18:25:07.130 INFO 14938 --- [ main] o.s.b.devtools.RemoteSpringApplication : Started RemoteSpringApplication in 0.74 seconds (JVM running for 1.105) Note Because the remote client is using the same classpath as the real application it can directly read application properties. This is how the spring.devtools.remote.secret property is read and passed to the server for authentication. Tip It’s always advisable to use https:// as the connection protocol so that traffic is encrypted and passwords cannot be intercepted. Tip If you need to use a proxy to access the remote application, configure the spring.devtools.remote.proxy.host and spring.devtools.remote.proxy.port properties. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 48 Remote update The remote client will monitor your application classpath for changes in the same way as the local restart. Any updated resource will be pushed to the remote application and (if required) trigger a restart. This can be quite helpful if you are iterating on a feature that uses a cloud service that you don’t have locally. Generally remote updates and restarts are much quicker than a full rebuild and deploy cycle. Note Files are only monitored when the remote client is running. If you change a file before starting the remote client, it won’t be pushed to the remote server. Remote debug tunnel Java remote debugging is useful when diagnosing issues on a remote application. Unfortunately, it’s not always possible to enable remote debugging when your application is deployed outside of your data center. Remote debugging can also be tricky to setup if you are using a container based technology such as Docker. To help work around these limitations, devtools supports tunneling of remote debug traffic over HTTP. The remote client provides a local server on port 8000 that you can attach a remote debugger to. Once a connection is established, debug traffic is sent over HTTP to the remote application. You can use the spring.devtools.remote.debug.local-port property if you want to use a different port. You’ll need to ensure that your remote application is started with remote debugging enabled. Often this can be achieved by configuring JAVA_OPTS. For example, with Cloud Foundry you can add the following to your manifest.yml: --- env: JAVA_OPTS: "-Xdebug -Xrunjdwp:server=y,transport=dt_socket,suspend=n" Tip Notice that you don’t need to pass an address=NNNN option to -Xrunjdwp. If omitted Java will simply pick a random free port. Note Debugging a remote service over the Internet can be slow and you might need to increase timeouts in your IDE. For example, in Eclipse you can select Java → Debug from Preferences… and change the Debugger timeout (ms) to a more suitable value (60000 works well in most situations). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 49 21. Packaging your application for production Executable jars can be used for production deployment. As they are self-contained, they are also ideally suited for cloud-based deployment. For additional “production ready” features, such as health, auditing and metric REST or JMX end- points; consider adding spring-boot-actuator. See Part V, “Spring Boot Actuator: Production- ready features” for details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 50 22. What to read next You should now have good understanding of how you can use Spring Boot along with some best practices that you should follow. You can now go on to learn about specific Spring Boot features in depth, or you could skip ahead and read about the “production ready” aspects of Spring Boot. Part IV. Spring Boot features This section dives into the details of Spring Boot. Here you can learn about the key features that you will want to use and customize. If you haven’t already, you might want to read the Part II, “Getting started” and Part III, “Using Spring Boot” sections so that you have a good grounding of the basics. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 52 23. SpringApplication The SpringApplication class provides a convenient way to bootstrap a Spring application that will be started from a main() method. In many situations you can just delegate to the static SpringApplication.run method: public static void main(String[] args) { SpringApplication.run(MySpringConfiguration.class, args); } When your application starts you should see something similar to the following: . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: v1.4.0.BUILD-SNAPSHOT 2013-07-31 00:08:16.117 INFO 56603 --- [ main] o.s.b.s.app.SampleApplication : Starting SampleApplication v0.1.0 on mycomputer with PID 56603 (/apps/myapp.jar started by pwebb) 2013-07-31 00:08:16.166 INFO 56603 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@6e5a8246: startup date [Wed Jul 31 00:08:16 PDT 2013]; root of context hierarchy 2014-03-04 13:09:54.912 INFO 41370 --- [ main] .t.TomcatEmbeddedServletContainerFactory : Server initialized with port: 8080 2014-03-04 13:09:56.501 INFO 41370 --- [ main] o.s.b.s.app.SampleApplication : Started SampleApplication in 2.992 seconds (JVM running for 3.658) By default INFO logging messages will be shown, including some relevant startup details such as the user that launched the application. 23.1 Customizing the Banner The banner that is printed on start up can be changed by adding a banner.txt file to your classpath, or by setting banner.location to the location of such a file. If the file has an unusual encoding you can set banner.charset (default is UTF-8). In addition to a text file, you can also add a banner.gif, banner.jpg or banner.png image file to your classpath, or set a banner.image.location property. Images will be converted into an ASCII art representation and printed above any text banner. Inside your banner.txt file you can use any of the following placeholders: Table 23.1. Banner variables Variable Description ${application.version} The version number of your application as declared in MANIFEST.MF. For example Implementation-Version: 1.0 is printed as 1.0. ${application.formatted-version} The version number of your application as declared in MANIFEST.MF formatted for display (surrounded with brackets and prefixed with v). For example (v1.0). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 53 Variable Description ${spring-boot.version} The Spring Boot version that you are using. For example 1.4.0.BUILD-SNAPSHOT. ${spring-boot.formatted-version} The Spring Boot version that you are using formatted for display (surrounded with brackets and prefixed with v). For example (v1.4.0.BUILD-SNAPSHOT). ${Ansi.NAME} (or ${AnsiColor.NAME}, ${AnsiBackground.NAME}, ${AnsiStyle.NAME}) Where NAME is the name of an ANSI escape code. See AnsiPropertySource for details. ${application.title} The title of your application as declared in MANIFEST.MF. For example Implementation-Title: MyApp is printed as MyApp. Tip The SpringApplication.setBanner(…) method can be used if you want to generate a banner programmatically. Use the org.springframework.boot.Banner interface and implement your own printBanner() method. You can also use the spring.main.banner-mode property to determine if the banner has to be printed on System.out (console), using the configured logger (log) or not at all (off). The printed banner will be registered as a singleton bean under the name springBootBanner. Note YAML maps off to false so make sure to add quotes if you want to disable the banner in your application. spring: main: banner-mode: "off" 23.2 Customizing SpringApplication If the SpringApplication defaults aren’t to your taste you can instead create a local instance and customize it. For example, to turn off the banner you would write: public static void main(String[] args) { SpringApplication app = new SpringApplication(MySpringConfiguration.class); app.setBannerMode(Banner.Mode.OFF); app.run(args); } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 54 Note The constructor arguments passed to SpringApplication are configuration sources for spring beans. In most cases these will be references to @Configuration classes, but they could also be references to XML configuration or to packages that should be scanned. It is also possible to configure the SpringApplication using an application.properties file. See Chapter 24, Externalized Configuration for details. For a complete list of the configuration options, see the SpringApplication Javadoc. 23.3 Fluent builder API If you need to build an ApplicationContext hierarchy (multiple contexts with a parent/ child relationship), or if you just prefer using a ‘fluent’ builder API, you can use the SpringApplicationBuilder. The SpringApplicationBuilder allows you to chain together multiple method calls, and includes parent and child methods that allow you to create a hierarchy. For example: new SpringApplicationBuilder() .bannerMode(Banner.Mode.OFF) .sources(Parent.class) .child(Application.class) .run(args); Note There are some restrictions when creating an ApplicationContext hierarchy, e.g. Web components must be contained within the child context, and the same Environment will be used for both parent and child contexts. See the SpringApplicationBuilder Javadoc for full details. 23.4 Application events and listeners In addition to the usual Spring Framework events, such as ContextRefreshedEvent, a SpringApplication sends some additional application events. Note Some events are actually triggered before the ApplicationContext is created so you cannot register a listener on those as a @Bean. You can register them via the SpringApplication.addListeners(…) or SpringApplicationBuilder.listeners(…) methods. If you want those listeners to be registered automatically regardless of the way the application is created you can add a META-INF/spring.factories file to your project and reference your listener(s) using the org.springframework.context.ApplicationListener key. org.springframework.context.ApplicationListener=com.example.project.MyListener Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 55 Application events are sent in the following order, as your application runs: 1. An ApplicationStartedEvent is sent at the start of a run, but before any processing except the registration of listeners and initializers. 2. An ApplicationEnvironmentPreparedEvent is sent when the Environment to be used in the context is known, but before the context is created. 3. An ApplicationPreparedEvent is sent just before the refresh is started, but after bean definitions have been loaded. 4. An ApplicationReadyEvent is sent after the refresh and any related callbacks have been processed to indicate the application is ready to service requests. 5. An ApplicationFailedEvent is sent if there is an exception on startup. Tip You often won’t need to use application events, but it can be handy to know that they exist. Internally, Spring Boot uses events to handle a variety of tasks. 23.5 Web environment A SpringApplication will attempt to create the right type of ApplicationContext on your behalf. By default, an AnnotationConfigApplicationContext or AnnotationConfigEmbeddedWebApplicationContext will be used, depending on whether you are developing a web application or not. The algorithm used to determine a ‘web environment’ is fairly simplistic (based on the presence of a few classes). You can use setWebEnvironment(boolean webEnvironment) if you need to override the default. It is also possible to take complete control of the ApplicationContext type that will be used by calling setApplicationContextClass(…). Tip It is often desirable to call setWebEnvironment(false) when using SpringApplication within a JUnit test. 23.6 Accessing application arguments If you need to access the application arguments that were passed to SpringApplication.run(… ) you can inject a org.springframework.boot.ApplicationArguments bean. The ApplicationArguments interface provides access to both the raw String[] arguments as well as parsed option and non-option arguments: import org.springframework.boot.* import org.springframework.beans.factory.annotation.* import org.springframework.stereotype.* @Component public class MyBean { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 56 @Autowired public MyBean(ApplicationArguments args) { boolean debug = args.containsOption("debug"); List files = args.getNonOptionArgs(); // if run with "--debug logfile.txt" debug=true, files=["logfile.txt"] } } Tip Spring Boot will also register a CommandLinePropertySource with the Spring Environment. This allows you to also inject single application arguments using the @Value annotation. 23.7 Using the ApplicationRunner or CommandLineRunner If you need to run some specific code once the SpringApplication has started, you can implement the ApplicationRunner or CommandLineRunner interfaces. Both interfaces work in the same way and offer a single run method which will be called just before SpringApplication.run(…) completes. The CommandLineRunner interfaces provides access to application arguments as a simple string array, whereas the ApplicationRunner uses the ApplicationArguments interface discussed above. import org.springframework.boot.* import org.springframework.stereotype.* @Component public class MyBean implements CommandLineRunner { public void run(String... args) { // Do something... } } You can additionally implement the org.springframework.core.Ordered interface or use the org.springframework.core.annotation.Order annotation if several CommandLineRunner or ApplicationRunner beans are defined that must be called in a specific order. 23.8 Application exit Each SpringApplication will register a shutdown hook with the JVM to ensure that the ApplicationContext is closed gracefully on exit. All the standard Spring lifecycle callbacks (such as the DisposableBean interface, or the @PreDestroy annotation) can be used. In addition, beans may implement the org.springframework.boot.ExitCodeGenerator interface if they wish to return a specific exit code when the application ends. 23.9 Admin features It is possible to enable admin-related features for the application by specifying the spring.application.admin.enabled property. This exposes the SpringApplicationAdminMXBean on the platform MBeanServer. You could use this feature to administer your Spring Boot application remotely. This could also be useful for any service wrapper implementation. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 57 Tip If you want to know on which HTTP port the application is running, get the property with key local.server.port. Note Take care when enabling this feature as the MBean exposes a method to shutdown the application. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 58 24. Externalized Configuration Spring Boot allows you to externalize your configuration so you can work with the same application code in different environments. You can use properties files, YAML files, environment variables and command-line arguments to externalize configuration. Property values can be injected directly into your beans using the @Value annotation, accessed via Spring’s Environment abstraction or bound to structured objects via @ConfigurationProperties. Spring Boot uses a very particular PropertySource order that is designed to allow sensible overriding of values. Properties are considered in the following order: 1. @TestPropertySource annotations on your tests. 2. Command line arguments. 3. Properties from SPRING_APPLICATION_JSON (inline JSON embedded in an environment variable or system property) 4. ServletConfig init parameters. 5. ServletContext init parameters. 6. JNDI attributes from java:comp/env. 7. Java System properties (System.getProperties()). 8. OS environment variables. 9. A RandomValuePropertySource that only has properties in random.*. 10.Profile-specific application properties outside of your packaged jar (application- {profile}.properties and YAML variants) 11.Profile-specific application properties packaged inside your jar (application- {profile}.properties and YAML variants) 12.Application properties outside of your packaged jar (application.properties and YAML variants). 13.Application properties packaged inside your jar (application.properties and YAML variants). 14.@PropertySource annotations on your @Configuration classes. 15.Default properties (specified using SpringApplication.setDefaultProperties). To provide a concrete example, suppose you develop a @Component that uses a name property: import org.springframework.stereotype.* import org.springframework.beans.factory.annotation.* @Component public class MyBean { @Value("${name}") private String name; // ... } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 59 On your application classpath (e.g. inside your jar) you can have an application.properties that provides a sensible default property value for name. When running in a new environment, an application.properties can be provided outside of your jar that overrides the name; and for one-off testing, you can launch with a specific command line switch (e.g. java -jar app.jar -- name="Spring"). Tip The SPRING_APPLICATION_JSON properties can be supplied on the command line with an environment variable. For example in a UN*X shell: $ SPRING_APPLICATION_JSON='{"foo":{"bar":"spam"}}' java -jar myapp.jar In this example you will end up with foo.bar=spam in the Spring Environment. You can also supply the JSON as spring.application.json in a System variable: $ java -Dspring.application.json='{"foo":"bar"}' -jar myapp.jar or command line argument: $ java -jar myapp.jar --spring.application.json='{"foo":"bar"}' or as a JNDI variable java:comp/env/spring.application.json. 24.1 Configuring random values The RandomValuePropertySource is useful for injecting random values (e.g. into secrets or test cases). It can produce integers, longs, uuids or strings, e.g. my.secret=${random.value} my.number=${random.int} my.bignumber=${random.long} my.uuid=${random.uuid} my.number.less.than.ten=${random.int(10)} my.number.in.range=${random.int[1024,65536]} The random.int* syntax is OPEN value (,max) CLOSE where the OPEN,CLOSE are any character and value,max are integers. If max is provided then value is the minimum value and max is the maximum (exclusive). 24.2 Accessing command line properties By default SpringApplication will convert any command line option arguments (starting with ‘--’, e.g. --server.port=9000) to a property and add it to the Spring Environment. As mentioned above, command line properties always take precedence over other property sources. If you don’t want command line properties to be added to the Environment you can disable them using SpringApplication.setAddCommandLineProperties(false). 24.3 Application property files SpringApplication will load properties from application.properties files in the following locations and add them to the Spring Environment: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 60 1. A /config subdirectory of the current directory. 2. The current directory 3. A classpath /config package 4. The classpath root The list is ordered by precedence (properties defined in locations higher in the list override those defined in lower locations). Note You can also use YAML ('.yml') files as an alternative to '.properties'. If you don’t like application.properties as the configuration file name you can switch to another by specifying a spring.config.name environment property. You can also refer to an explicit location using the spring.config.location environment property (comma-separated list of directory locations, or file paths). $ java -jar myproject.jar --spring.config.name=myproject or $ java -jar myproject.jar --spring.config.location=classpath:/default.properties,classpath:/ override.properties Warning spring.config.name and spring.config.location are used very early to determine which files have to be loaded so they have to be defined as an environment property (typically OS env, system property or command line argument). If spring.config.location contains directories (as opposed to files) they should end in / (and will be appended with the names generated from spring.config.name before being loaded, including profile-specific file names). Files specified in spring.config.location are used as-is, with no support for profile-specific variants, and will be overridden by any profile-specific properties. The default search path classpath:,classpath:/config,file:,file:config/ is always used, irrespective of the value of spring.config.location. This search path is ordered from lowest to highest precedence (file:config/ wins). If you do specify your own locations, they take precedence over all of the default locations and use the same lowest to highest precedence ordering. In that way you can set up default values for your application in application.properties (or whatever other basename you choose with spring.config.name) and override it at runtime with a different file, keeping the defaults. Note If you use environment variables rather than system properties, most operating systems disallow period-separated key names, but you can use underscores instead (e.g. SPRING_CONFIG_NAME instead of spring.config.name). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 61 Note If you are running in a container then JNDI properties (in java:comp/env) or servlet context initialization parameters can be used instead of, or as well as, environment variables or system properties. 24.4 Profile-specific properties In addition to application.properties files, profile-specific properties can also be defined using the naming convention application-{profile}.properties. The Environment has a set of default profiles (by default [default]) which are used if no active profiles are set (i.e. if no profiles are explicitly activated then properties from application-default.properties are loaded). Profile-specific properties are loaded from the same locations as standard application.properties, with profile-specific files always overriding the non-specific ones irrespective of whether the profile-specific files are inside or outside your packaged jar. If several profiles are specified, a last wins strategy applies. For example, profiles specified by the spring.profiles.active property are added after those configured via the SpringApplication API and therefore take precedence. Note If you have specified any files in spring.config.location, profile-specific variants of those files will not be considered. Use directories in`spring.config.location` if you also want to also use profile-specific properties. 24.5 Placeholders in properties The values in application.properties are filtered through the existing Environment when they are used so you can refer back to previously defined values (e.g. from System properties). app.name=MyApp app.description=${app.name} is a Spring Boot application Tip You can also use this technique to create ‘short’ variants of existing Spring Boot properties. See the Section 71.4, “Use ‘short’ command line arguments” how-to for details. 24.6 Using YAML instead of Properties YAML is a superset of JSON, and as such is a very convenient format for specifying hierarchical configuration data. The SpringApplication class will automatically support YAML as an alternative to properties whenever you have the SnakeYAML library on your classpath. Note If you use ‘Starters’ SnakeYAML will be automatically provided via spring-boot-starter. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 62 Loading YAML Spring Framework provides two convenient classes that can be used to load YAML documents. The YamlPropertiesFactoryBean will load YAML as Properties and the YamlMapFactoryBean will load YAML as a Map. For example, the following YAML document: environments: dev: url: http://dev.bar.com name: Developer Setup prod: url: http://foo.bar.com name: My Cool App Would be transformed into these properties: environments.dev.url=http://dev.bar.com environments.dev.name=Developer Setup environments.prod.url=http://foo.bar.com environments.prod.name=My Cool App YAML lists are represented as property keys with [index] dereferencers, for example this YAML: my: servers: - dev.bar.com - foo.bar.com Would be transformed into these properties: my.servers[0]=dev.bar.com my.servers[1]=foo.bar.com To bind to properties like that using the Spring DataBinder utilities (which is what @ConfigurationProperties does) you need to have a property in the target bean of type java.util.List (or Set) and you either need to provide a setter, or initialize it with a mutable value, e.g. this will bind to the properties above @ConfigurationProperties(prefix="my") public class Config { private List servers = new ArrayList(); public List getServers() { return this.servers; } } Exposing YAML as properties in the Spring Environment The YamlPropertySourceLoader class can be used to expose YAML as a PropertySource in the Spring Environment. This allows you to use the familiar @Value annotation with placeholders syntax to access YAML properties. Multi-profile YAML documents You can specify multiple profile-specific YAML documents in a single file by using a spring.profiles key to indicate when the document applies. For example: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 63 server: address: 192.168.1.100 --- spring: profiles: development server: address: 127.0.0.1 --- spring: profiles: production server: address: 192.168.1.120 In the example above, the server.address property will be 127.0.0.1 if the development profile is active. If the development and production profiles are not enabled, then the value for the property will be 192.168.1.100. The default profiles are activated if none are explicitly active when the application context starts. So in this YAML we set a value for security.user.password that is only available in the "default" profile: server: port: 8000 --- spring: profiles: default security: user: password: weak whereas in this example, the password is always set because it isn’t attached to any profile, and it would have to be explicitly reset in all other profiles as necessary: server: port: 8000 security: user: password: weak Spring profiles designated using the "spring.profiles" element may optionally be negated using the ! character. If both negated and non-negated profiles are specified for a single document, at least one non-negated profile must match and no negated profiles may match. YAML shortcomings YAML files can’t be loaded via the @PropertySource annotation. So in the case that you need to load values that way, you need to use a properties file. 24.7 Type-safe Configuration Properties Using the @Value("${property}") annotation to inject configuration properties can sometimes be cumbersome, especially if you are working with multiple properties or your data is hierarchical in nature. Spring Boot provides an alternative method of working with properties that allows strongly typed beans to govern and validate the configuration of your application. For example: @Component @ConfigurationProperties(prefix="connection") public class ConnectionSettings { private String username; private InetAddress remoteAddress; Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 64 // ... getters and setters } Note The getters and setters are advisable, since binding is via standard Java Beans property descriptors, just like in Spring MVC. They are mandatory for immutable types or those that are directly coercible from String. As long as they are initialized, maps, collections, and arrays need a getter but not necessarily a setter since they can be mutated by the binder. If there is a setter, Maps, collections, and arrays can be created. Maps and collections can be expanded with only a getter, whereas arrays require a setter. Nested POJO properties can also be created (so a setter is not mandatory) if they have a default constructor, or a constructor accepting a single value that can be coerced from String. Some people use Project Lombok to add getters and setters automatically. Note Contrary to @Value, SpEL expressions are not evaluated prior to injecting a value in the relevant @ConfigurationProperties bean. The @EnableConfigurationProperties annotation is automatically applied to your project so that any beans annotated with @ConfigurationProperties will be configured from the Environment properties. This style of configuration works particularly well with the SpringApplication external YAML configuration: # application.yml connection: username: admin remoteAddress: 192.168.1.1 # additional configuration as required To work with @ConfigurationProperties beans you can just inject them in the same way as any other bean. @Service public class MyService { @Autowired private ConnectionSettings connection; //... @PostConstruct public void openConnection() { Server server = new Server(); this.connection.configure(server); } } It is also possible to shortcut the registration of @ConfigurationProperties bean definitions by simply listing the properties classes directly in the @EnableConfigurationProperties annotation: @Configuration @EnableConfigurationProperties(ConnectionSettings.class) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 65 public class MyConfiguration { } Note When @ConfigurationProperties bean is registered that way, the bean will have a conventional name: -, where is the environment key prefix specified in the @ConfigurationProperties annotation and the fully qualified name of the bean. If the annotation does not provide any prefix, only the fully qualified name of the bean is used. The bean name in the example above will be connection- com.example.ConnectionSettings, assuming that ConnectionSettings sits in the com.example package. Tip Using @ConfigurationProperties also allows you to generate meta-data files that can be used by IDEs. See the Appendix B, Configuration meta-data appendix for details. Third-party configuration As well as using @ConfigurationProperties to annotate a class, you can also use it on @Bean methods. This can be particularly useful when you want to bind properties to third-party components that are outside of your control. To configure a bean from the Environment properties, add @ConfigurationProperties to its bean registration: @ConfigurationProperties(prefix = "foo") @Bean public FooComponent fooComponent() { ... } Any property defined with the foo prefix will be mapped onto that FooComponent bean in a similar manner as the ConnectionSettings example above. Relaxed binding Spring Boot uses some relaxed rules for binding Environment properties to @ConfigurationProperties beans, so there doesn’t need to be an exact match between the Environment property name and the bean property name. Common examples where this is useful include dashed separated (e.g. context-path binds to contextPath), and capitalized (e.g. PORT binds to port) environment properties. For example, given the following @ConfigurationProperties class: @Component @ConfigurationProperties(prefix="person") public class ConnectionSettings { private String firstName; public String getFirstName() { return this.firstName; } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 66 public void setFirstName(String firstName) { this.firstName = firstName; } } The following properties names can all be used: Table 24.1. relaxed binding Property Note person.firstNameStandard camel case syntax. person.first- name Dashed notation, recommended for use in .properties and .yml files. person.first_nameUnderscore notation, alternative format for use in .properties and .yml files. PERSON_FIRST_NAMEUpper case format. Recommended when using a system environment variables. Properties conversion Spring will attempt to coerce the external application properties to the right type when it binds to the @ConfigurationProperties beans. If you need custom type conversion you can provide a ConversionService bean (with bean id conversionService) or custom property editors (via a CustomEditorConfigurer bean) or custom Converters (with bean definitions annotated as @ConfigurationPropertiesBinding). Note As this bean is requested very early during the application lifecycle, make sure to limit the dependencies that your ConversionService is using. Typically, any dependency that you require may not be fully initialized at creation time. You may want to rename your custom ConversionService if it’s not required for configuration keys coercion and only rely on custom converters qualified with @ConfigurationPropertiesBinding. @ConfigurationProperties Validation Spring Boot will attempt to validate external configuration, by default using JSR-303 (if it is on the classpath). You can simply add JSR-303 javax.validation constraint annotations to your @ConfigurationProperties class: @Component @ConfigurationProperties(prefix="connection") public class ConnectionSettings { @NotNull private InetAddress remoteAddress; // ... getters and setters } In order to validate values of nested properties, you must annotate the associated field as @Valid to trigger its validation. For example, building upon the above ConnectionSettings example: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 67 @Component @ConfigurationProperties(prefix="connection") public class ConnectionSettings { @NotNull @Valid private RemoteAddress remoteAddress; // ... getters and setters public static class RemoteAddress { @NotEmpty public String hostname; // ... getters and setters } } You can also add a custom Spring Validator by creating a bean definition called configurationPropertiesValidator. There is a Validation sample so you can see how to set things up. Tip The spring-boot-actuator module includes an endpoint that exposes all @ConfigurationProperties beans. Simply point your web browser to /configprops or use the equivalent JMX endpoint. See the Production ready features. section for details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 68 25. Profiles Spring Profiles provide a way to segregate parts of your application configuration and make it only available in certain environments. Any @Component or @Configuration can be marked with @Profile to limit when it is loaded: @Configuration @Profile("production") public class ProductionConfiguration { // ... } In the normal Spring way, you can use a spring.profiles.active Environment property to specify which profiles are active. You can specify the property in any of the usual ways, for example you could include it in your application.properties: spring.profiles.active=dev,hsqldb or specify on the command line using the switch --spring.profiles.active=dev,hsqldb. 25.1 Adding active profiles The spring.profiles.active property follows the same ordering rules as other properties, the highest PropertySource will win. This means that you can specify active profiles in application.properties then replace them using the command line switch. Sometimes it is useful to have profile-specific properties that add to the active profiles rather than replace them. The spring.profiles.include property can be used to unconditionally add active profiles. The SpringApplication entry point also has a Java API for setting additional profiles (i.e. on top of those activated by the spring.profiles.active property): see the setAdditionalProfiles() method. For example, when an application with following properties is run using the switch -- spring.profiles.active=prod the proddb and prodmq profiles will also be activated: --- my.property: fromyamlfile --- spring.profiles: prod spring.profiles.include: proddb,prodmq Note Remember that the spring.profiles property can be defined in a YAML document to determine when this particular document is included in the configuration. See Section 71.7, “Change configuration depending on the environment” for more details. 25.2 Programmatically setting profiles You can programmatically set active profiles by calling SpringApplication.setAdditionalProfiles(…) before your application runs. It is also possible to activate profiles using Spring’s ConfigurableEnvironment interface. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 69 25.3 Profile-specific configuration files Profile-specific variants of both application.properties (or application.yml) and files referenced via @ConfigurationProperties are considered as files are loaded. See Section 24.4, “Profile-specific properties” for details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 70 26. Logging Spring Boot uses Commons Logging for all internal logging, but leaves the underlying log implementation open. Default configurations are provided for Java Util Logging, Log4J2 and Logback. In each case loggers are pre-configured to use console output with optional file output also available. By default, If you use the ‘Starters’, Logback will be used for logging. Appropriate Logback routing is also included to ensure that dependent libraries that use Java Util Logging, Commons Logging, Log4J or SLF4J will all work correctly. Tip There are a lot of logging frameworks available for Java. Don’t worry if the above list seems confusing. Generally you won’t need to change your logging dependencies and the Spring Boot defaults will work just fine. 26.1 Log format The default log output from Spring Boot looks like this: 2014-03-05 10:57:51.112 INFO 45469 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/7.0.52 2014-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2014-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1358 ms 2014-03-05 10:57:51.698 INFO 45469 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/] 2014-03-05 10:57:51.702 INFO 45469 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*] The following items are output: • Date and Time — Millisecond precision and easily sortable. • Log Level — ERROR, WARN, INFO, DEBUG or TRACE. • Process ID. • A --- separator to distinguish the start of actual log messages. • Thread name — Enclosed in square brackets (may be truncated for console output). • Logger name — This is usually the source class name (often abbreviated). • The log message. Note Logback does not have a FATAL level (it is mapped to ERROR) 26.2 Console output The default log configuration will echo messages to the console as they are written. By default ERROR, WARN and INFO level messages are logged. You can also enable a “debug” mode by starting your application with a --debug flag. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 71 $ java -jar myapp.jar --debug Note you can also specify debug=true in your application.properties. When the debug mode is enabled, a selection of core loggers (embedded container, Hibernate and Spring Boot) are configured to output more information. Enabling the debug mode does not configure your application to log all messages with DEBUG level. Alternatively, you can enable a “trace” mode by starting your application with a --trace flag (or trace=true in your application.properties). This will enable trace logging for a selection of core loggers (embedded container, Hibernate schema generation and the whole Spring portfolio). Color-coded output If your terminal supports ANSI, color output will be used to aid readability. You can set spring.output.ansi.enabled to a supported value to override the auto detection. Color coding is configured using the %clr conversion word. In its simplest form the converter will color the output according to the log level, for example: %clr(%5p) The mapping of log level to a color is as follows: Level Color FATAL Red ERROR Red WARN Yellow INFO Green DEBUG Green TRACE Green Alternatively, you can specify the color or style that should be used by providing it as an option to the conversion. For example, to make the text yellow: %clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){yellow} The following colors and styles are supported: • blue • cyan • faint • green • magenta Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 72 • red • yellow 26.3 File output By default, Spring Boot will only log to the console and will not write log files. If you want to write log files in addition to the console output you need to set a logging.file or logging.path property (for example in your application.properties). The following table shows how the logging.* properties can be used together: Table 26.1. Logging properties logging.filelogging.pathExample Description (none) (none) Console only logging. Specific file (none) my.log Writes to the specified log file. Names can be an exact location or relative to the current directory. (none) Specific directory /var/log Writes spring.log to the specified directory. Names can be an exact location or relative to the current directory. Log files will rotate when they reach 10 Mb and as with console output, ERROR, WARN and INFO level messages are logged by default. Note The logging system is initialized early in the application lifecycle and as such logging properties will not be found in property files loaded via @PropertySource annotations. Tip Logging properties are independent of the actual logging infrastructure. As a result, specific configuration keys (such as logback.configurationFile for Logback) are not managed by spring Boot. 26.4 Log Levels All the supported logging systems can have the logger levels set in the Spring Environment (so for example in application.properties) using ‘logging.level.*=LEVEL’ where ‘LEVEL’ is one of TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF. The root logger can be configured using logging.level.root. Example application.properties: logging.level.root=WARN logging.level.org.springframework.web=DEBUG logging.level.org.hibernate=ERROR Note By default Spring Boot remaps Thymeleaf INFO messages so that they are logged at DEBUG level. This helps to reduce noise in the standard log output. See LevelRemappingAppender for details of how you can apply remapping in your own configuration. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 73 26.5 Custom log configuration The various logging systems can be activated by including the appropriate libraries on the classpath, and further customized by providing a suitable configuration file in the root of the classpath, or in a location specified by the Spring Environment property logging.config. You can force Spring Boot to use a particular logging system using the org.springframework.boot.logging.LoggingSystem system property. The value should be the fully-qualified class name of a LoggingSystem implementation. You can also disable Spring Boot’s logging configuration entirely by using a value of none. Note Since logging is initialized before the ApplicationContext is created, it isn’t possible to control logging from @PropertySources in Spring @Configuration files. System properties and the conventional Spring Boot external configuration files work just fine.) Depending on your logging system, the following files will be loaded: Logging System Customization Logback logback-spring.xml, logback- spring.groovy, logback.xml or logback.groovy Log4j2 log4j2-spring.xml or log4j2.xml JDK (Java Util Logging) logging.properties Note When possible we recommend that you use the -spring variants for your logging configuration (for example logback-spring.xml rather than logback.xml). If you use standard configuration locations, Spring cannot completely control log initialization. Warning There are known classloading issues with Java Util Logging that cause problems when running from an ‘executable jar’. We recommend that you avoid it if at all possible. To help with the customization some other properties are transferred from the Spring Environment to System properties: Spring Environment System Property Comments logging.exception- conversion-word LOG_EXCEPTION_CONVERSION_WORDThe conversion word that’s used when logging exceptions. logging.file LOG_FILE Used in default log configuration if defined. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 74 Spring Environment System Property Comments logging.path LOG_PATH Used in default log configuration if defined. logging.pattern.console CONSOLE_LOG_PATTERN The log pattern to use on the console (stdout). (Not supported with JDK logger.) logging.pattern.file FILE_LOG_PATTERN The log pattern to use in a file (if LOG_FILE enabled). (Not supported with JDK logger.) logging.pattern.level LOG_LEVEL_PATTERN The format to use to render the log level (default %5p). (The logging.pattern.level form is only supported by Logback.) PID PID The current process ID (discovered if possible and when not already defined as an OS environment variable). All the logging systems supported can consult System properties when parsing their configuration files. See the default configurations in spring-boot.jar for examples. Tip If you want to use a placeholder in a logging property, you should use Spring Boot’s syntax and not the syntax of the underlying framework. Notably, if you’re using Logback, you should use : as the delimiter between a property name and its default value and not :-. Tip You can add MDC and other ad-hoc content to log lines by overriding only the LOG_LEVEL_PATTERN (or logging.pattern.level with Logback). For example, if you use logging.pattern.level=user:%X{user} %5p then the default log format will contain an MDC entry for "user" if it exists, e.g. 2015-09-30 12:30:04.031 user:juergen INFO 22174 --- [ nio-8080-exec-0] demo.Controller Handling authenticated request 26.6 Logback extensions Spring Boot includes a number of extensions to Logback which can help with advanced configuration. You can use these extensions in your logback-spring.xml configuration file. Note You cannot use extensions in the standard logback.xml configuration file since it’s loaded too early. You need to either use logback-spring.xml or define a logging.config property. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 75 Profile-specific configuration The tag allows you to optionally include or exclude sections of configuration based on the active Spring profiles. Profile sections are supported anywhere within the element. Use the name attribute to specify which profile accepts the configuration. Multiple profiles can be specified using a comma-separated list. Environment properties The tag allows you to surface properties from the Spring Environment for use within Logback. This can be useful if you want to access values from your application.properties file in your logback configuration. The tag works in a similar way to Logback’s standard tag, but rather than specifying a direct value you specify the source of the property (from the Environment). You can use the scope attribute if you need to store the property somewhere other than in local scope. If you need a fallback value in case the property is not set in the Environment, you can use the defaultValue attribute. ${fluentHost} ... Tip The RelaxedPropertyResolver is used to access Environment properties. If specify the source in dashed notation (my-property-name) all the relaxed variations will be tried (myPropertyName, MY_PROPERTY_NAME etc). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 76 27. Developing web applications Spring Boot is well suited for web application development. You can easily create a self-contained HTTP server using embedded Tomcat, Jetty, or Undertow. Most web applications will use the spring-boot- starter-web module to get up and running quickly. If you haven’t yet developed a Spring Boot web application you can follow the "Hello World!" example in the Getting started section. 27.1 The ‘Spring Web MVC framework’ The Spring Web MVC framework (often referred to as simply ‘Spring MVC’) is a rich ‘model view controller’ web framework. Spring MVC lets you create special @Controller or @RestController beans to handle incoming HTTP requests. Methods in your controller are mapped to HTTP using @RequestMapping annotations. Here is a typical example @RestController to serve JSON data: @RestController @RequestMapping(value="/users") public class MyRestController { @RequestMapping(value="/{user}", method=RequestMethod.GET) public User getUser(@PathVariable Long user) { // ... } @RequestMapping(value="/{user}/customers", method=RequestMethod.GET) List getUserCustomers(@PathVariable Long user) { // ... } @RequestMapping(value="/{user}", method=RequestMethod.DELETE) public User deleteUser(@PathVariable Long user) { // ... } } Spring MVC is part of the core Spring Framework and detailed information is available in the reference documentation. There are also several guides available at spring.io/guides that cover Spring MVC. Spring MVC auto-configuration Spring Boot provides auto-configuration for Spring MVC that works well with most applications. The auto-configuration adds the following features on top of Spring’s defaults: • Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans. • Support for serving static resources, including support for WebJars (see below). • Automatic registration of Converter, GenericConverter, Formatter beans. • Support for HttpMessageConverters (see below). • Automatic registration of MessageCodesResolver (see below). • Static index.html support. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 77 • Custom Favicon support. • Automatic use of a ConfigurableWebBindingInitializer bean (see below). If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc. If you want to keep Spring Boot MVC features, and you just want to add additional MVC configuration (interceptors, formatters, view controllers etc.) you can add your own @Bean of type WebMvcConfigurerAdapter, but without @EnableWebMvc. HttpMessageConverters Spring MVC uses the HttpMessageConverter interface to convert HTTP requests and responses. Sensible defaults are included out of the box, for example Objects can be automatically converted to JSON (using the Jackson library) or XML (using the Jackson XML extension if available, else using JAXB). Strings are encoded using UTF-8 by default. If you need to add or customize converters you can use Spring Boot’s HttpMessageConverters class: import org.springframework.boot.autoconfigure.web.HttpMessageConverters; import org.springframework.context.annotation.*; import org.springframework.http.converter.*; @Configuration public class MyConfiguration { @Bean public HttpMessageConverters customConverters() { HttpMessageConverter additional = ... HttpMessageConverter another = ... return new HttpMessageConverters(additional, another); } } Any HttpMessageConverter bean that is present in the context will be added to the list of converters. You can also override default converters that way. Custom JSON Serializers and Deserializers If you’re using Jackson to serialize and deserialize JSON data, you might want to write your own JsonSerializer and JsonDeserializer classes. Custom serializers are usually registered with Jackson via a Module, but Spring Boot provides an alternative @JsonComponent annotation which makes it easier to directly register Spring Beans. You can use @JsonComponent directly on JsonSerializer or JsonDeserializer implementations. You can also use it on classes that contains serializers/deserializers as inner-classes. For example: import java.io.*; import com.fasterxml.jackson.core.*; import com.fasterxml.jackson.databind.*; import org.springframework.boot.jackson.*; @JsonComponent public class Example { public static class Serializer extends JsonSerializer { // ... } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 78 public static class Deserializer extends JsonDeserializer { // ... } } All @JsonComponent beans in the ApplicationContext will be automatically registered with Jackson, and since @JsonComponent is meta-annotated with @Component, the usual component- scanning rules apply. Spring Boot also provides JsonObjectSerializer and JsonObjectDeserializer base classes which provide useful alternatives to the standard Jackson versions when serializing Objects. See the Javadoc for details. MessageCodesResolver Spring MVC has a strategy for generating error codes for rendering error messages from binding errors: MessageCodesResolver. Spring Boot will create one for you if you set the spring.mvc.message- codes-resolver.format property PREFIX_ERROR_CODE or POSTFIX_ERROR_CODE (see the enumeration in DefaultMessageCodesResolver.Format). Static Content By default Spring Boot will serve static content from a directory called /static (or /public or / resources or /META-INF/resources) in the classpath or from the root of the ServletContext. It uses the ResourceHttpRequestHandler from Spring MVC so you can modify that behavior by adding your own WebMvcConfigurerAdapter and overriding the addResourceHandlers method. In a stand-alone web application the default servlet from the container is also enabled, and acts as a fallback, serving content from the root of the ServletContext if Spring decides not to handle it. Most of the time this will not happen (unless you modify the default MVC configuration) because Spring will always be able to handle requests through the DispatcherServlet. You can customize the static resource locations using spring.resources.staticLocations (replacing the default values with a list of directory locations). If you do this the default welcome page detection will switch to your custom locations, so if there is an index.html in any of your locations on startup, it will be the home page of the application. In addition to the ‘standard’ static resource locations above, a special case is made for Webjars content. Any resources with a path in /webjars/** will be served from jar files if they are packaged in the Webjars format. Tip Do not use the src/main/webapp directory if your application will be packaged as a jar. Although this directory is a common standard, it will only work with war packaging and it will be silently ignored by most build tools if you generate a jar. Spring Boot also supports advanced resource handling features provided by Spring MVC, allowing use cases such as cache busting static resources or using version agnostic URLs for Webjars. For example, the following configuration will configure a cache busting solution for all static resources, effectively adding a content hash in URLs, such as : Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 79 spring.resources.chain.strategy.content.enabled=true spring.resources.chain.strategy.content.paths=/** Note Links to resources are rewritten at runtime in template, thanks to a ResourceUrlEncodingFilter, auto-configured for Thymeleaf, Velocity and FreeMarker. You should manually declare this filter when using JSPs. Other template engines aren’t automatically supported right now, but can be with custom template macros/helpers and the use of the ResourceUrlProvider. When loading resources dynamically with, for example, a JavaScript module loader, renaming files is not an option. That’s why other strategies are also supported and can be combined. A "fixed" strategy will add a static version string in the URL, without changing the file name: spring.resources.chain.strategy.content.enabled=true spring.resources.chain.strategy.content.paths=/** spring.resources.chain.strategy.fixed.enabled=true spring.resources.chain.strategy.fixed.paths=/js/lib/ spring.resources.chain.strategy.fixed.version=v12 With this configuration, JavaScript modules located under "/js/lib/" will use a fixed versioning strategy "/v12/js/lib/mymodule.js" while other resources will still use the content one . See ResourceProperties for more of the supported options. Tip This feature has been thoroughly described in a dedicated blog post and in Spring Framework’s reference documentation. ConfigurableWebBindingInitializer Spring MVC uses a WebBindingInitializer to initialize a WebDataBinder for a particular request. If you create your own ConfigurableWebBindingInitializer @Bean, Spring Boot will automatically configure Spring MVC to use it. Template engines As well as REST web services, you can also use Spring MVC to serve dynamic HTML content. Spring MVC supports a variety of templating technologies including Velocity, FreeMarker and JSPs. Many other templating engines also ship their own Spring MVC integrations. Spring Boot includes auto-configuration support for the following templating engines: • FreeMarker • Groovy • Thymeleaf • Velocity (deprecated in 1.4) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 80 • Mustache Tip JSPs should be avoided if possible, there are several known limitations when using them with embedded servlet containers. When you’re using one of these templating engines with the default configuration, your templates will be picked up automatically from src/main/resources/templates. Tip IntelliJ IDEA orders the classpath differently depending on how you run your application. Running your application in the IDE via its main method will result in a different ordering to when you run your application using Maven or Gradle or from its packaged jar. This can cause Spring Boot to fail to find the templates on the classpath. If you’re affected by this problem you can reorder the classpath in the IDE to place the module’s classes and resources first. Alternatively, you can configure the template prefix to search every templates directory on the classpath: classpath*:/templates/. Error Handling Spring Boot provides an /error mapping by default that handles all errors in a sensible way, and it is registered as a ‘global’ error page in the servlet container. For machine clients it will produce a JSON response with details of the error, the HTTP status and the exception message. For browser clients there is a ‘whitelabel’ error view that renders the same data in HTML format (to customize it just add a View that resolves to ‘error’). To replace the default behaviour completely you can implement ErrorController and register a bean definition of that type, or simply add a bean of type ErrorAttributes to use the existing mechanism but replace the contents. Tip The BasicErrorController can be used as a base class for a custom ErrorController. This is particularly useful if you want to add a handler for a new content type (the default is to handle text/html specifically and provide a fallback for everything else). To do that just extend BasicErrorController and add a public method with a @RequestMapping that has a produces attribute, and create a bean of your new type. You can also define a @ControllerAdvice to customize the JSON document to return for a particular controller and/or exception type. @ControllerAdvice(basePackageClasses = FooController.class) public class FooControllerAdvice extends ResponseEntityExceptionHandler { @ExceptionHandler(YourException.class) @ResponseBody ResponseEntity handleControllerException(HttpServletRequest request, Throwable ex) { HttpStatus status = getStatus(request); return new ResponseEntity<>(new CustomErrorType(status.value(), ex.getMessage()), status); } private HttpStatus getStatus(HttpServletRequest request) { Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code"); if (statusCode == null) { return HttpStatus.INTERNAL_SERVER_ERROR; Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 81 } return HttpStatus.valueOf(statusCode); } } In the example above, if YourException is thrown by a controller defined in the same package as FooController, a json representation of the CustomerErrorType POJO will be used instead of the ErrorAttributes representation. Custom error pages If you want to display a custom HTML error page for a given status code, you add a file to an /error folder. Error pages can either be static HTML (i.e. added under any of the static resource folders) or built using templates. The name of the file should be the exact status code or a series mask. For example, to map 404 to a static HTML file, your folder structure would look like this: src/ +- main/ +- java/ | + +- resources/ +- public/ +- error/ | +- 404.html +- To map all 5xx errors using a FreeMarker template, you’d have a structure like this: src/ +- main/ +- java/ | + +- resources/ +- templates/ +- error/ | +- 5xx.ftl +- For more complex mappings you can also add beans that implement the ErrorViewResolver interface. public class MyErrorViewResolver implements ErrorViewResolver { @Override public ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status, Map model) { // Use the request or status to optionally return a ModelAndView return ... } } You can also use regular Spring MVC features like @ExceptionHandler methods and @ControllerAdvice. The ErrorController will then pick up any unhandled exceptions. Mapping error pages outside of Spring MVC For applications that aren’t using Spring MVC, you can use the ErrorPageRegistrar interface to directly register ErrorPages. This abstraction works directly with the underlying embedded servlet container and will work even if you don’t have a Spring MVC DispatcherServlet. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 82 @Bean public ErrorPageRegistrar errorPageRegistrar(){ return new MyErrorPageRegistrar(); } // ... private static class MyErrorPageRegistrar implements ErrorPageRegistrar { @Override public void registerErrorPages(ErrorPageRegistry registry) { registry.addErrorPages(new ErrorPage(HttpStatus.BAD_REQUEST, "/400")); } } N.B. if you register an ErrorPage with a path that will end up being handled by a Filter (e.g. as is common with some non-Spring web frameworks, like Jersey and Wicket), then the Filter has to be explicitly registered as an ERROR dispatcher, e.g. @Bean public FilterRegistrationBean myFilter() { FilterRegistrationBean registration = new FilterRegistrationBean(); registration.setFilter(new MyFilter()); ... registration.setDispatcherTypes(EnumSet.allOf(DispatcherType.class)); return registration; } (the default FilterRegistrationBean does not include the ERROR dispatcher type). Error Handling on WebSphere Application Server When deployed to a servlet container, a Spring Boot uses its error page filter to forward a request with an error status to the appropriate error page. The request can only be forwarded to the correct error page if the response has not already been committed. By default, WebSphere Application Server 8.0 and later commits the response upon successful completion of a servlet’s service method. You should disable this behaviour by setting com.ibm.ws.webcontainer.invokeFlushAfterService to false Spring HATEOAS If you’re developing a RESTful API that makes use of hypermedia, Spring Boot provides auto- configuration for Spring HATEOAS that works well with most applications. The auto-configuration replaces the need to use @EnableHypermediaSupport and registers a number of beans to ease building hypermedia-based applications including a LinkDiscoverers (for client side support) and an ObjectMapper configured to correctly marshal responses into the desired representation. The ObjectMapper will be customized based on the spring.jackson.* properties or a Jackson2ObjectMapperBuilder bean if one exists. You can take control of Spring HATEOAS’s configuration by using @EnableHypermediaSupport. Note that this will disable the ObjectMapper customization described above. CORS support Cross-origin resource sharing (CORS) is a W3C specification implemented by most browsers that allows you to specify in a flexible way what kind of cross domain requests are authorized, instead of using some less secure and less powerful approaches like IFRAME or JSONP. As of version 4.2, Spring MVC supports CORS out of the box. Using controller method CORS configuration with @CrossOrigin annotations in your Spring Boot application does not require any Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 83 specific configuration. Global CORS configuration can be defined by registering a WebMvcConfigurer bean with a customized addCorsMappings(CorsRegistry) method: @Configuration public class MyConfiguration { @Bean public WebMvcConfigurer corsConfigurer() { return new WebMvcConfigurerAdapter() { @Override public void addCorsMappings(CorsRegistry registry) { registry.addMapping("/api/**"); } }; } } 27.2 JAX-RS and Jersey If you prefer the JAX-RS programming model for REST endpoints you can use one of the available implementations instead of Spring MVC. Jersey 1.x and Apache CXF work quite well out of the box if you just register their Servlet or Filter as a @Bean in your application context. Jersey 2.x has some native Spring support so we also provide auto-configuration support for it in Spring Boot together with a starter. To get started with Jersey 2.x just include the spring-boot-starter-jersey as a dependency and then you need one @Bean of type ResourceConfig in which you register all the endpoints: @Component public class JerseyConfig extends ResourceConfig { public JerseyConfig() { register(Endpoint.class); } } You can also register an arbitrary number of beans implementing ResourceConfigCustomizer for more advanced customizations. All the registered endpoints should be @Components with HTTP resource annotations (@GET etc.), e.g. @Component @Path("/hello") public class Endpoint { @GET public String message() { return "Hello"; } } Since the Endpoint is a Spring @Component its lifecycle is managed by Spring and you can @Autowired dependencies and inject external configuration with @Value. The Jersey servlet will be registered and mapped to /* by default. You can change the mapping by adding @ApplicationPath to your ResourceConfig. By default Jersey will be set up as a Servlet in a @Bean of type ServletRegistrationBean named jerseyServletRegistration. By default, the servlet will be initialized lazily but you Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 84 can customize it with spring.jersey.servlet.load-on-startup .You can disable or override that bean by creating one of your own with the same name. You can also use a Filter instead of a Servlet by setting spring.jersey.type=filter (in which case the @Bean to replace or override is jerseyFilterRegistration). The servlet has an @Order which you can set with spring.jersey.filter.order. Both the Servlet and the Filter registrations can be given init parameters using spring.jersey.init.* to specify a map of properties. There is a Jersey sample so you can see how to set things up. There is also a Jersey 1.x sample. Note that in the Jersey 1.x sample that the spring-boot maven plugin has been configured to unpack some Jersey jars so they can be scanned by the JAX-RS implementation (because the sample asks for them to be scanned in its Filter registration). You may need to do the same if any of your JAX- RS resources are packaged as nested jars. 27.3 Embedded servlet container support Spring Boot includes support for embedded Tomcat, Jetty, and Undertow servers. Most developers will simply use the appropriate ‘Starter’ to obtain a fully configured instance. By default the embedded server will listen for HTTP requests on port 8080. Servlets, Filters, and listeners When using an embedded servlet container you can register Servlets, Filters and all the listeners from the Servlet spec (e.g. HttpSessionListener) either by using Spring beans or by scanning for Servlet components. Registering Servlets, Filters, and listeners as Spring beans Any Servlet, Filter or Servlet *Listener instance that is a Spring bean will be registered with the embedded container. This can be particularly convenient if you want to refer to a value from your application.properties during configuration. By default, if the context contains only a single Servlet it will be mapped to /. In the case of multiple Servlet beans the bean name will be used as a path prefix. Filters will map to /*. If convention-based mapping is not flexible enough you can use the ServletRegistrationBean, FilterRegistrationBean and ServletListenerRegistrationBean classes for complete control. Servlet Context Initialization Embedded servlet containers will not directly execute the Servlet 3.0+ javax.servlet.ServletContainerInitializer interface, or Spring’s org.springframework.web.WebApplicationInitializer interface. This is an intentional design decision intended to reduce the risk that 3rd party libraries designed to run inside a war will break Spring Boot applications. If you need to perform servlet context initialization in a Spring Boot application, you should register a bean that implements the org.springframework.boot.context.embedded.ServletContextInitializer interface. The single onStartup method provides access to the ServletContext, and can easily be used as an adapter to an existing WebApplicationInitializer if necessary. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 85 Scanning for Servlets, Filters, and listeners When using an embedded container, automatic registration of @WebServlet, @WebFilter, and @WebListener annotated classes can be enabled using @ServletComponentScan. Tip @ServletComponentScan will have no effect in a standalone container, where the container’s built-in discovery mechanisms will be used instead. The EmbeddedWebApplicationContext Under the hood Spring Boot uses a new type of ApplicationContext for embedded servlet container support. The EmbeddedWebApplicationContext is a special type of WebApplicationContext that bootstraps itself by searching for a single EmbeddedServletContainerFactory bean. Usually a TomcatEmbeddedServletContainerFactory, JettyEmbeddedServletContainerFactory, or UndertowEmbeddedServletContainerFactory will have been auto-configured. Note You usually won’t need to be aware of these implementation classes. Most applications will be auto-configured and the appropriate ApplicationContext and EmbeddedServletContainerFactory will be created on your behalf. Customizing embedded servlet containers Common servlet container settings can be configured using Spring Environment properties. Usually you would define the properties in your application.properties file. Common server settings include: • Network settings: listen port for incoming HTTP requests (server.port), interface address to bind to server.address, etc. • Session settings: whether the session is persistent (server.session.persistence), session timeout (server.session.timeout), location of session data (server.session.store-dir) and session-cookie configuration (server.session.cookie.*). • Error management: location of the error page (server.error.path), etc. • SSL • HTTP compression Spring Boot tries as much as possible to expose common settings but this is not always possible. For those cases, dedicated namespaces offer server-specific customizations (see server.tomcat and server.undertow). For instance, access logs can be configured with specific features of the embedded servlet container. Tip See the ServerProperties class for a complete list. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 86 Programmatic customization If you need to configure your embedded servlet container programmatically you can register a Spring bean that implements the EmbeddedServletContainerCustomizer interface. EmbeddedServletContainerCustomizer provides access to the ConfigurableEmbeddedServletContainer which includes numerous customization setter methods. import org.springframework.boot.context.embedded.*; import org.springframework.stereotype.Component; @Component public class CustomizationBean implements EmbeddedServletContainerCustomizer { @Override public void customize(ConfigurableEmbeddedServletContainer container) { container.setPort(9000); } } Customizing ConfigurableEmbeddedServletContainer directly If the above customization techniques are too limited, you can register the TomcatEmbeddedServletContainerFactory, JettyEmbeddedServletContainerFactory or UndertowEmbeddedServletContainerFactory bean yourself. @Bean public EmbeddedServletContainerFactory servletContainer() { TomcatEmbeddedServletContainerFactory factory = new TomcatEmbeddedServletContainerFactory(); factory.setPort(9000); factory.setSessionTimeout(10, TimeUnit.MINUTES); factory.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND, "/notfound.html")); return factory; } Setters are provided for many configuration options. Several protected method ‘hooks’ are also provided should you need to do something more exotic. See the source code documentation for details. JSP limitations When running a Spring Boot application that uses an embedded servlet container (and is packaged as an executable archive), there are some limitations in the JSP support. • With Tomcat it should work if you use war packaging, i.e. an executable war will work, and will also be deployable to a standard container (not limited to, but including Tomcat). An executable jar will not work because of a hard coded file pattern in Tomcat. • Jetty does not currently work as an embedded container with JSPs. • Undertow does not support JSPs. There is a JSP sample so you can see how to set things up. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 87 28. Security If Spring Security is on the classpath then web applications will be secure by default with ‘basic’ authentication on all HTTP endpoints. To add method-level security to a web application you can also add @EnableGlobalMethodSecurity with your desired settings. Additional information can be found in the Spring Security Reference. The default AuthenticationManager has a single user (‘user’ username and random password, printed at INFO level when the application starts up) Using default security password: 78fa095d-3f4c-48b1-ad50-e24c31d5cf35 Note If you fine-tune your logging configuration, ensure that the org.springframework.boot.autoconfigure.security category is set to log INFO messages, otherwise the default password will not be printed. You can change the password by providing a security.user.password. This and other useful properties are externalized via SecurityProperties (properties prefix "security"). The default security configuration is implemented in SecurityAutoConfiguration and in the classes imported from there (SpringBootWebSecurityConfiguration for web security and AuthenticationManagerConfiguration for authentication configuration which is also relevant in non-web applications). To switch off the default web security configuration completely you can add a bean with @EnableWebSecurity (this does not disable the authentication manager configuration). To customize it you normally use external properties and beans of type WebSecurityConfigurerAdapter (e.g. to add form-based login). To also switch off the authentication manager configuration you can add a bean of type AuthenticationManager, or else configure the global AuthenticationManager by autowiring an AuthenticationManagerBuilder into a method in one of your @Configuration classes. There are several secure applications in the Spring Boot samples to get you started with common use cases. The basic features you get out of the box in a web application are: • An AuthenticationManager bean with in-memory store and a single user (see SecurityProperties.User for the properties of the user). • Ignored (insecure) paths for common static resource locations (/css/**, /js/**, /images/** and **/favicon.ico). • HTTP Basic security for all other endpoints. • Security events published to Spring’s ApplicationEventPublisher (successful and unsuccessful authentication and access denied). • Common low-level features (HSTS, XSS, CSRF, caching) provided by Spring Security are on by default. All of the above can be switched on and off or modified using external properties (security.*). To override the access rules without changing any other auto-configured features add a @Bean of type WebSecurityConfigurerAdapter with @Order(SecurityProperties.ACCESS_OVERRIDE_ORDER). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 88 28.1 OAuth2 If you have spring-security-oauth2 on your classpath you can take advantage of some auto- configuration to make it easy to set up Authorization or Resource Server. Authorization Server To create an Authorization Server and grant access tokens you need to use @EnableAuthorizationServer and provide security.oauth2.client.client-id and security.oauth2.client.client-secret] properties. The client will be registered for you in an in-memory repository. Having done that you will be able to use the client credentials to create an access token, for example: $ curl client:secret@localhost:8080/oauth/token -d grant_type=password -d username=user -d password=pwd The basic auth credentials for the /token endpoint are the client-id and client-secret. The user credentials are the normal Spring Security user details (which default in Spring Boot to “user” and a random password). To switch off the auto-configuration and configure the Authorization Server features yourself just add a @Bean of type AuthorizationServerConfigurer. Resource Server To use the access token you need a Resource Server (which can be the same as the Authorization Server). Creating a Resource Server is easy, just add @EnableResourceServer and provide some configuration to allow the server to decode access tokens. If your application is also an Authorization Server it already knows how to decode tokens, so there is nothing else to do. If your app is a standalone service then you need to give it some more configuration, one of the following options: • security.oauth2.resource.user-info-uri to use the /me resource (e.g. https:// uaa.run.pivotal.io/userinfo on PWS) • security.oauth2.resource.token-info-uri to use the token decoding endpoint (e.g. https://uaa.run.pivotal.io/check_token on PWS). If you specify both the user-info-uri and the token-info-uri then you can set a flag to say that one is preferred over the other (prefer-token-info=true is the default). Alternatively (instead of user-info-uri or token-info-uri) if the tokens are JWTs you can configure a security.oauth2.resource.jwt.key-value to decode them locally (where the key is a verification key). The verification key value is either a symmetric secret or PEM-encoded RSA public key. If you don’t have the key and it’s public you can provide a URI where it can be downloaded (as a JSON object with a “value” field) with security.oauth2.resource.jwt.key-uri. E.g. on PWS: $ curl https://uaa.run.pivotal.io/token_key {"alg":"SHA256withRSA","value":"-----BEGIN PUBLIC KEY-----\nMIIBI...\n-----END PUBLIC KEY-----\n"} Warning If you use the security.oauth2.resource.jwt.key-uri the authorization server needs to be running when your application starts up. It will log a warning if it can’t find the key, and tell you what to do to fix it. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 89 28.2 Token Type in User Info Google, and certain other 3rd party identity providers, are more strict about the token type name that is sent in the headers to the user info endpoint. The default is “Bearer” which suits most providers and matches the spec, but if you need to change it you can set security.oauth2.resource.token- type. 28.3 Customizing the User Info RestTemplate If you have a user-info-uri, the resource server features use an OAuth2RestTemplate internally to fetch user details for authentication. This is provided as a qualified @Bean with id userInfoRestTemplate, but you shouldn’t need to know that to just use it. The default should be fine for most providers, but occasionally you might need to add additional interceptors, or change the request authenticator (which is how the token gets attached to outgoing requests). To add a customization just create a bean of type UserInfoRestTemplateCustomizer - it has a single method that will be called after the bean is created but before it is initialized. The rest template that is being customized here is only used internally to carry out authentication. Tip To set an RSA key value in YAML use the “pipe” continuation marker to split it over multiple lines (“|”) and remember to indent the key value (it’s a standard YAML language feature). Example: security: oauth2: resource: jwt: keyValue: | -----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKC... -----END PUBLIC KEY----- Client To make your web-app into an OAuth2 client you can simply add @EnableOAuth2Client and Spring Boot will create a OAuth2ClientContext and OAuth2ProtectedResourceDetails that are necessary to create an OAuth2RestOperations. Spring Boot does not automatically create such bean but you can easily create your own: @Bean public OAuth2RestTemplate oauth2RestTemplate(OAuth2ClientContext oauth2ClientContext, OAuth2ProtectedResourceDetails details) { return new OAuth2RestTemplate(details, oauth2ClientContext); } Note You may want to add a qualifier and review your configuration as more than one RestTemplate may be defined in your application. This configuration uses security.oauth2.client.* as credentials (the same as you might be using in the Authorization Server), but in addition it will need to know the authorization and token URIs in the Authorization Server. For example: application.yml. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 90 security: oauth2: client: clientId: bd1c0a783ccdd1c9b9e4 clientSecret: 1a9030fbca47a5b2c28e92f19050bb77824b5ad1 accessTokenUri: https://github.com/login/oauth/access_token userAuthorizationUri: https://github.com/login/oauth/authorize clientAuthenticationScheme: form An application with this configuration will redirect to Github for authorization when you attempt to use the OAuth2RestTemplate. If you are already signed into Github you won’t even notice that it has authenticated. These specific credentials will only work if your application is running on port 8080 (register your own client app in Github or other provider for more flexibility). To limit the scope that the client asks for when it obtains an access token you can set security.oauth2.client.scope (comma separated or an array in YAML). By default the scope is empty and it is up to Authorization Server to decide what the defaults should be, usually depending on the settings in the client registration that it holds. Note There is also a setting for security.oauth2.client.client-authentication-scheme which defaults to “header” (but you might need to set it to “form” if, like Github for instance, your OAuth2 provider doesn’t like header authentication). In fact, the security.oauth2.client.* properties are bound to an instance of AuthorizationCodeResourceDetails so all its properties can be specified. Tip In a non-web application you can still create an OAuth2RestOperations and it is still wired into the security.oauth2.client.* configuration. In this case it is a “client credentials token grant” you will be asking for if you use it (and there is no need to use @EnableOAuth2Client or @EnableOAuth2Sso). To prevent that infrastructure to be defined, just remove the security.oauth2.client.client-id from your configuration (or make it the empty string). Single Sign On An OAuth2 Client can be used to fetch user details from the provider (if such features are available) and then convert them into an Authentication token for Spring Security. The Resource Server above support this via the user-info-uri property This is the basis for a Single Sign On (SSO) protocol based on OAuth2, and Spring Boot makes it easy to participate by providing an annotation @EnableOAuth2Sso. The Github client above can protect all its resources and authenticate using the Github /user/ endpoint, by adding that annotation and declaring where to find the endpoint (in addition to the security.oauth2.client.* configuration already listed above): application.yml. security: oauth2: ... resource: userInfoUri: https://api.github.com/user preferTokenInfo: false Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 91 Since all paths are secure by default, there is no “home” page that you can show to unauthenticated users and invite them to login (by visiting the /login path, or the path specified by security.oauth2.sso.login-path). To customize the access rules or paths to protect, so you can add a “home” page for instance, @EnableOAuth2Sso can be added to a WebSecurityConfigurerAdapter and the annotation will cause it to be decorated and enhanced with the necessary pieces to get the /login path working. For example, here we simply allow unauthenticated access to the home page at "/" and keep the default for everything else: @Configuration public class WebSecurityConfiguration extends WebSecurityConfigurerAdapter { @Override public void init(WebSecurity web) { web.ignore("/"); } @Override protected void configure(HttpSecurity http) throws Exception { http.antMatcher("/**").authorizeRequests().anyRequest().authenticated(); } } 28.4 Actuator Security If the Actuator is also in use, you will find: • The management endpoints are secure even if the application endpoints are insecure. • Security events are transformed into AuditEvents and published to the AuditService. • The default user will have the ADMIN role as well as the USER role. The Actuator security features can be modified using external properties (management.security.*). To override the application access rules add a @Bean of type WebSecurityConfigurerAdapter and use @Order(SecurityProperties.ACCESS_OVERRIDE_ORDER) if you don’t want to override the actuator access rules, or @Order(ManagementServerProperties.ACCESS_OVERRIDE_ORDER) if you do want to override the actuator access rules. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 92 29. Working with SQL databases The Spring Framework provides extensive support for working with SQL databases. From direct JDBC access using JdbcTemplate to complete ‘object relational mapping’ technologies such as Hibernate. Spring Data provides an additional level of functionality, creating Repository implementations directly from interfaces and using conventions to generate queries from your method names. 29.1 Configure a DataSource Java’s javax.sql.DataSource interface provides a standard method of working with database connections. Traditionally a DataSource uses a URL along with some credentials to establish a database connection. Embedded Database Support It’s often convenient to develop applications using an in-memory embedded database. Obviously, in- memory databases do not provide persistent storage; you will need to populate your database when your application starts and be prepared to throw away data when your application ends. Tip The ‘How-to’ section includes a section on how to initialize a database Spring Boot can auto-configure embedded H2, HSQL and Derby databases. You don’t need to provide any connection URLs, simply include a build dependency to the embedded database that you want to use. For example, typical POM dependencies would be: org.springframework.boot spring-boot-starter-data-jpa org.hsqldb hsqldb runtime Note You need a dependency on spring-jdbc for an embedded database to be auto-configured. In this example it’s pulled in transitively via spring-boot-starter-data-jpa. Tip If, for whatever reason, you do configure the connection URL for an embedded database, care should be taken to ensure that the database’s automatic shutdown is disabled. If you’re using H2 you should use DB_CLOSE_ON_EXIT=FALSE to do so. If you’re using HSQLDB, you should ensure that shutdown=true is not used. Disabling the database’s automatic shutdown allows Spring Boot to control when the database is closed, thereby ensuring that it happens once access to the database is no longer needed. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 93 Connection to a production database Production database connections can also be auto-configured using a pooling DataSource. Here’s the algorithm for choosing a specific implementation: • We prefer the Tomcat pooling DataSource for its performance and concurrency, so if that is available we always choose it. • Otherwise, if HikariCP is available we will use it. • If neither the Tomcat pooling datasource nor HikariCP are available and if Commons DBCP is available we will use it, but we don’t recommend it in production. • Lastly, if Commons DBCP2 is available we will use it. If you use the spring-boot-starter-jdbc or spring-boot-starter-data-jpa ‘starters’ you will automatically get a dependency to tomcat-jdbc. Note You can bypass that algorithm completely and specify the connection pool to use via the spring.datasource.type property. This is especially important if you are running your application in a Tomcat container as tomcat-jdbc is provided by default. Tip Additional connection pools can always be configured manually. If you define your own DataSource bean, auto-configuration will not occur. DataSource configuration is controlled by external configuration properties in spring.datasource.*. For example, you might declare the following section in application.properties: spring.datasource.url=jdbc:mysql://localhost/test spring.datasource.username=dbuser spring.datasource.password=dbpass spring.datasource.driver-class-name=com.mysql.jdbc.Driver Tip You often won’t need to specify the driver-class-name since Spring boot can deduce it for most databases from the url. Note For a pooling DataSource to be created we need to be able to verify that a valid Driver class is available, so we check for that before doing anything. I.e. if you set spring.datasource.driver-class-name=com.mysql.jdbc.Driver then that class has to be loadable. See DataSourceProperties for more of the supported options. These are the standard options that work regardless of the actual implementation. It is also possible to fine-tune implementation-specific settings using their respective prefix (spring.datasource.tomcat.*, spring.datasource.hikari.*, Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 94 spring.datasource.dbcp.* and spring.datasource.dbcp2.*). Refer to the documentation of the connection pool implementation you are using for more details. For instance, if you are using the Tomcat connection pool you could customize many additional settings: # Number of ms to wait before throwing an exception if no connection is available. spring.datasource.tomcat.max-wait=10000 # Maximum number of active connections that can be allocated from this pool at the same time. spring.datasource.tomcat.max-active=50 # Validate the connection before borrowing it from the pool. spring.datasource.tomcat.test-on-borrow=true Connection to a JNDI DataSource If you are deploying your Spring Boot application to an Application Server you might want to configure and manage your DataSource using your Application Servers built-in features and access it using JNDI. The spring.datasource.jndi-name property can be used as an alternative to the spring.datasource.url, spring.datasource.username and spring.datasource.password properties to access the DataSource from a specific JNDI location. For example, the following section in application.properties shows how you can access a JBoss AS defined DataSource: spring.datasource.jndi-name=java:jboss/datasources/customers 29.2 Using JdbcTemplate Spring’s JdbcTemplate and NamedParameterJdbcTemplate classes are auto-configured and you can @Autowire them directly into your own beans: import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.stereotype.Component; @Component public class MyBean { private final JdbcTemplate jdbcTemplate; @Autowired public MyBean(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } // ... } 29.3 JPA and ‘Spring Data’ The Java Persistence API is a standard technology that allows you to ‘map’ objects to relational databases. The spring-boot-starter-data-jpa POM provides a quick way to get started. It provides the following key dependencies: • Hibernate — One of the most popular JPA implementations. • Spring Data JPA — Makes it easy to implement JPA-based repositories. • Spring ORMs — Core ORM support from the Spring Framework. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 95 Tip We won’t go into too many details of JPA or Spring Data here. You can follow the ‘Accessing Data with JPA’ guide from spring.io and read the Spring Data JPA and Hibernate reference documentation. Entity Classes Traditionally, JPA ‘Entity’ classes are specified in a persistence.xml file. With Spring Boot this file is not necessary and instead ‘Entity Scanning’ is used. By default all packages below your main configuration class (the one annotated with @EnableAutoConfiguration or @SpringBootApplication) will be searched. Any classes annotated with @Entity, @Embeddable or @MappedSuperclass will be considered. A typical entity class would look something like this: package com.example.myapp.domain; import java.io.Serializable; import javax.persistence.*; @Entity public class City implements Serializable { @Id @GeneratedValue private Long id; @Column(nullable = false) private String name; @Column(nullable = false) private String state; // ... additional members, often include @OneToMany mappings protected City() { // no-args constructor required by JPA spec // this one is protected since it shouldn't be used directly } public City(String name, String state) { this.name = name; this.country = country; } public String getName() { return this.name; } public String getState() { return this.state; } // ... etc } Tip You can customize entity scanning locations using the @EntityScan annotation. See the Section 75.4, “Separate @Entity definitions from Spring configuration” how-to. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 96 Spring Data JPA Repositories Spring Data JPA repositories are interfaces that you can define to access data. JPA queries are created automatically from your method names. For example, a CityRepository interface might declare a findAllByState(String state) method to find all cities in a given state. For more complex queries you can annotate your method using Spring Data’s Query annotation. Spring Data repositories usually extend from the Repository or CrudRepository interfaces. If you are using auto-configuration, repositories will be searched from the package containing your main configuration class (the one annotated with @EnableAutoConfiguration or @SpringBootApplication) down. Here is a typical Spring Data repository: package com.example.myapp.domain; import org.springframework.data.domain.*; import org.springframework.data.repository.*; public interface CityRepository extends Repository { Page findAll(Pageable pageable); City findByNameAndCountryAllIgnoringCase(String name, String country); } Tip We have barely scratched the surface of Spring Data JPA. For complete details check their reference documentation. Creating and dropping JPA databases By default, JPA databases will be automatically created only if you use an embedded database (H2, HSQL or Derby). You can explicitly configure JPA settings using spring.jpa.* properties. For example, to create and drop tables you can add the following to your application.properties. spring.jpa.hibernate.ddl-auto=create-drop Note Hibernate’s own internal property name for this (if you happen to remember it better) is hibernate.hbm2ddl.auto. You can set it, along with other Hibernate native properties, using spring.jpa.properties.* (the prefix is stripped before adding them to the entity manager). Example: spring.jpa.properties.hibernate.globally_quoted_identifiers=true passes hibernate.globally_quoted_identifiers to the Hibernate entity manager. By default the DDL execution (or validation) is deferred until the ApplicationContext has started. There is also a spring.jpa.generate-ddl flag, but it is not used if Hibernate autoconfig is active because the ddl-auto settings are more fine-grained. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 97 29.4 Using H2’s web console The H2 database provides a browser-based console that Spring Boot can auto-configure for you. The console will be auto-configured when the following conditions are met: • You are developing a web application • com.h2database:h2 is on the classpath • You are using Spring Boot’s developer tools Tip If you are not using Spring Boot’s developer tools, but would still like to make use of H2’s console, then you can do so by configuring the spring.h2.console.enabled property with a value of true. The H2 console is only intended for use during development so care should be taken to ensure that spring.h2.console.enabled is not set to true in production. Changing the H2 console’s path By default the console will be available at /h2-console. You can customize the console’s path using the spring.h2.console.path property. Securing the H2 console When Spring Security is on the classpath and basic auth is enabled, the H2 console will be automatically secured using basic auth. The following properties can be used to customize the security configuration: • security.user.role • security.basic.authorize-mode • security.basic.enabled Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 98 30. Using jOOQ Java Object Oriented Querying (jOOQ) is a popular product from Data Geekery which generates Java code from your database, and lets you build type safe SQL queries through its fluent API. Both the commercial and open source editions can be used with Spring Boot. 30.1 Code Generation In order to use jOOQ type-safe queries, you need to generate Java classes from your database schema. You can follow the instructions in the jOOQ user manual. If you are using the jooq-codegen-maven plugin (and you also use the spring-boot-starter-parent “parent POM”) you can safely omit the plugin’s tag. You can also use Spring Boot defined version variables (e.g. h2.version) to declare the plugin’s database dependency. Here’s an example: org.jooq jooq-codegen-maven ... com.h2database h2 ${h2.version} org.h2.Driver jdbc:h2:~/yourdatabase ... 30.2 Using DSLContext The fluent API offered by jOOQ is initiated via the org.jooq.DSLContext interface. Spring Boot will auto-configure a DSLContext as a Spring Bean and connect it to your application DataSource. To use the DSLContext you can just @Autowire it: @Component public class JooqExample implements CommandLineRunner { private final DSLContext create; @Autowired public JooqExample(DSLContext dslContext) { this.create = dslContext; } } Tip The jOOQ manual tends to use a variable named create to hold the DSLContext, we’ve done the same for this example. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 99 You can then use the DSLContext to construct your queries: public List authorsBornAfter1980() { return this.create.selectFrom(AUTHOR) .where(AUTHOR.DATE_OF_BIRTH.greaterThan(new GregorianCalendar(1980, 0, 1))) .fetch(AUTHOR.DATE_OF_BIRTH); } 30.3 Customizing jOOQ You can customize the SQL dialect used by jOOQ by setting spring.jooq.sql-dialect in your application.properties. For example, to specify Postgres you would add: spring.jooq.sql-dialect=Postgres More advanced customizations can be achieved by defining your own @Bean definitions which will be used when the jOOQ Configuration is created. You can define beans for the following jOOQ Types: • ConnectionProvider • TransactionProvider • RecordMapperProvider • RecordListenerProvider • ExecuteListenerProvider • VisitListenerProvider You can also create your own org.jooq.Configuration @Bean if you want to take complete control of the jOOQ configuration. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 100 31. Working with NoSQL technologies Spring Data provides additional projects that help you access a variety of NoSQL technologies including MongoDB, Neo4J, Elasticsearch, Solr, Redis, Gemfire, Couchbase and Cassandra. Spring Boot provides auto-configuration for Redis, MongoDB, Neo4j, Elasticsearch, Solr and Cassandra; you can make use of the other projects, but you will need to configure them yourself. Refer to the appropriate reference documentation at projects.spring.io/spring-data. 31.1 Redis Redis is a cache, message broker and richly-featured key-value store. Spring Boot offers basic auto- configuration for the Jedis client library and abstractions on top of it provided by Spring Data Redis. There is a spring-boot-starter-data-redis ‘Starter’ for collecting the dependencies in a convenient way. Connecting to Redis You can inject an auto-configured RedisConnectionFactory, StringRedisTemplate or vanilla RedisTemplate instance as you would any other Spring Bean. By default the instance will attempt to connect to a Redis server using localhost:6379: @Component public class MyBean { private StringRedisTemplate template; @Autowired public MyBean(StringRedisTemplate template) { this.template = template; } // ... } If you add a @Bean of your own of any of the auto-configured types it will replace the default (except in the case of RedisTemplate the exclusion is based on the bean name ‘redisTemplate’ not its type). If commons-pool2 is on the classpath you will get a pooled connection factory by default. 31.2 MongoDB MongoDB is an open-source NoSQL document database that uses a JSON-like schema instead of traditional table-based relational data. Spring Boot offers several conveniences for working with MongoDB, including the spring-boot-starter-data-mongodb ‘Starter’. Connecting to a MongoDB database You can inject an auto-configured org.springframework.data.mongodb.MongoDbFactory to access Mongo databases. By default the instance will attempt to connect to a MongoDB server using the URL mongodb://localhost/test: import org.springframework.data.mongodb.MongoDbFactory; import com.mongodb.DB; @Component public class MyBean { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 101 private final MongoDbFactory mongo; @Autowired public MyBean(MongoDbFactory mongo) { this.mongo = mongo; } // ... public void example() { DB db = mongo.getDb(); // ... } } You can set spring.data.mongodb.uri property to change the URL and configure additional settings such as the replica set: spring.data.mongodb.uri=mongodb://user:secret@mongo1.example.com:12345,mongo2.example.com:23456/test Alternatively, as long as you’re using Mongo 2.x, specify a host/port. For example, you might declare the following in your application.properties: spring.data.mongodb.host=mongoserver spring.data.mongodb.port=27017 Note spring.data.mongodb.host and spring.data.mongodb.port are not supported if you’re using the Mongo 3.0 Java driver. In such cases, spring.data.mongodb.uri should be used to provide all of the configuration. Tip If spring.data.mongodb.port is not specified the default of 27017 is used. You could simply delete this line from the sample above. Tip If you aren’t using Spring Data Mongo you can inject com.mongodb.Mongo beans instead of using MongoDbFactory. You can also declare your own MongoDbFactory or Mongo bean if you want to take complete control of establishing the MongoDB connection. MongoTemplate Spring Data Mongo provides a MongoTemplate class that is very similar in its design to Spring’s JdbcTemplate. As with JdbcTemplate Spring Boot auto-configures a bean for you to simply inject: import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.mongodb.core.MongoTemplate; import org.springframework.stereotype.Component; @Component public class MyBean { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 102 private final MongoTemplate mongoTemplate; @Autowired public MyBean(MongoTemplate mongoTemplate) { this.mongoTemplate = mongoTemplate; } // ... } See the MongoOperations Javadoc for complete details. Spring Data MongoDB repositories Spring Data includes repository support for MongoDB. As with the JPA repositories discussed earlier, the basic principle is that queries are constructed for you automatically based on method names. In fact, both Spring Data JPA and Spring Data MongoDB share the same common infrastructure; so you could take the JPA example from earlier and, assuming that City is now a Mongo data class rather than a JPA @Entity, it will work in the same way. package com.example.myapp.domain; import org.springframework.data.domain.*; import org.springframework.data.repository.*; public interface CityRepository extends Repository { Page findAll(Pageable pageable); City findByNameAndCountryAllIgnoringCase(String name, String country); } Tip For complete details of Spring Data MongoDB, including its rich object mapping technologies, refer to their reference documentation. Embedded Mongo Spring Boot offers auto-configuration for Embedded Mongo. To use it in your Spring Boot application add a dependency on de.flapdoodle.embed:de.flapdoodle.embed.mongo. The port that Mongo will listen on can be configured using the spring.data.mongodb.port property. To use a randomly allocated free port use a value of zero. The MongoClient created by MongoAutoConfiguration will be automatically configured to use the randomly allocated port. If you have SLF4J on the classpath, output produced by Mongo will be automatically routed to a logger named org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongo. You can declare your own IMongodConfig and IRuntimeConfig beans to take control of the Mongo instance’s configuration and logging routing. 31.3 Neo4j Neo4j is an open-source NoSQL graph database that uses a rich data model of nodes related by first class relationships which is better suited for connected big data than traditional rdbms Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 103 approaches. Spring Boot offers several conveniences for working with Neo4j, including the spring- boot-starter-data-neo4j ‘Starter’. Connecting to a Neo4j database You can inject an auto-configured Neo4jSession, Session or Neo4jOperations instance as you would any other Spring Bean. By default the instance will attempt to connect to a Neo4j server using localhost:7474: @Component public class MyBean { private final Neo4jTemplate neo4jTemplate; @Autowired public MyBean(Neo4jTemplate neo4jTemplate) { this.neo4jTemplate = neo4jTemplate; } // ... } You can take full control of the configuration by adding a org.neo4j.ogm.config.Configuration @Bean of your own. Also, adding a @Bean of type Neo4jOperations disables the auto-configuration. You can configure the user and credentials to use via the spring.data.neo4j.* properties: spring.data.neo4j.uri=http://my-server:7474 spring.data.neo4j.username=neo4j spring.data.neo4j.password=secret Using the embedded mode Note Neo4j’s embedded mode is subject to a different licensing, make sure to review it before integrating the dependency in your application. If you add org.neo4j:neo4j-ogm-embedded-driver to the dependencies of your application, Spring Boot will automatically configure an in-process embedded instance of Neo4j that will not persist any data when your application shuts down. You can explicitly disable that mode using spring.data.neo4j.embedded.enabled=false. You can also enable persistence for the embedded mode: spring.data.neo4j.uri=file://var/tmp/graph.db Neo4jSession By default, the lifetime of the session is scope to the application. If you are running a web application you can change it to scope or request easily: spring.data.neo4j.session.scope=session Spring Data Neo4j repositories Spring Data includes repository support for Neo4j. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 104 In fact, both Spring Data JPA and Spring Data Neo4j share the same common infrastructure; so you could take the JPA example from earlier and, assuming that City is now a Neo4j OGM @NodeEntity rather than a JPA @Entity, it will work in the same way. Tip You can customize entity scanning locations using the @NodeEntityScan annotation. To enable repository support (and optionally support for @Transactional), add the following two annotations to your Spring configuration: @EnableNeo4jRepositories(basePackages = "com.example.myapp.repository") @EnableTransactionManagement Repository example package com.example.myapp.domain; import org.springframework.data.domain.*; import org.springframework.data.repository.*; public interface CityRepository extends GraphRepository { Page findAll(Pageable pageable); City findByNameAndCountry(String name, String country); } Tip For complete details of Spring Data Neo4j, including its rich object mapping technologies, refer to their reference documentation. 31.4 Gemfire Spring Data Gemfire provides convenient Spring-friendly tools for accessing the Pivotal Gemfire data management platform. There is a spring-boot-starter-data-gemfire ‘Starter’ for collecting the dependencies in a convenient way. There is currently no auto-configuration support for Gemfire, but you can enable Spring Data Repositories with a single annotation (@EnableGemfireRepositories). 31.5 Solr Apache Solr is a search engine. Spring Boot offers basic auto-configuration for the Solr 5 client library and abstractions on top of it provided by Spring Data Solr. There is a spring-boot-starter-data- solr ‘Starter’ for collecting the dependencies in a convenient way. Connecting to Solr You can inject an auto-configured SolrClient instance as you would any other Spring bean. By default the instance will attempt to connect to a server using localhost:8983/solr: @Component public class MyBean { private SolrClient solr; Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 105 @Autowired public MyBean(SolrClient solr) { this.solr = solr; } // ... } If you add a @Bean of your own of type SolrClient it will replace the default. Spring Data Solr repositories Spring Data includes repository support for Apache Solr. As with the JPA repositories discussed earlier, the basic principle is that queries are constructed for you automatically based on method names. In fact, both Spring Data JPA and Spring Data Solr share the same common infrastructure; so you could take the JPA example from earlier and, assuming that City is now a @SolrDocument class rather than a JPA @Entity, it will work in the same way. Tip For complete details of Spring Data Solr, refer to their reference documentation. 31.6 Elasticsearch Elasticsearch is an open source, distributed, real-time search and analytics engine. Spring Boot offers basic auto-configuration for the Elasticsearch and abstractions on top of it provided by Spring Data Elasticsearch. There is a spring-boot-starter-data-elasticsearch ‘Starter’ for collecting the dependencies in a convenient way. Connecting to Elasticsearch You can inject an auto-configured ElasticsearchTemplate or Elasticsearch Client instance as you would any other Spring Bean. By default the instance will embed a local in-memory server (a Node in ElasticSearch terms) and use the current working directory as the home directory for the server. In this setup, the first thing to do is to tell ElasticSearch where to store its files: spring.data.elasticsearch.properties.path.home=/foo/bar Alternatively, you can switch to a remote server (i.e. a TransportClient) by setting spring.data.elasticsearch.cluster-nodes to a comma-separated ‘host:port’ list. spring.data.elasticsearch.cluster-nodes=localhost:9300 @Component public class MyBean { private ElasticsearchTemplate template; @Autowired public MyBean(ElasticsearchTemplate template) { this.template = template; } // ... } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 106 If you add a @Bean of your own of type ElasticsearchTemplate it will replace the default. Spring Data Elasticsearch repositories Spring Data includes repository support for Elasticsearch. As with the JPA repositories discussed earlier, the basic principle is that queries are constructed for you automatically based on method names. In fact, both Spring Data JPA and Spring Data Elasticsearch share the same common infrastructure; so you could take the JPA example from earlier and, assuming that City is now an Elasticsearch @Document class rather than a JPA @Entity, it will work in the same way. Tip For complete details of Spring Data Elasticsearch, refer to their reference documentation. 31.7 Cassandra Cassandra is an open source, distributed database management system designed to handle large amounts of data across many commodity servers. Spring Boot offers auto-configuration for Cassandra and abstractions on top of it provided by Spring Data Cassandra. There is a spring-boot-starter- data-cassandra ‘Starter’ for collecting the dependencies in a convenient way. Connecting to Cassandra You can inject an auto-configured CassandraTemplate or a Cassandra Session instance as you would with any other Spring Bean. The spring.data.cassandra.* properties can be used to customize the connection. Generally you will provide keyspace-name and contact-points properties: spring.data.cassandra.keyspace-name=mykeyspace spring.data.cassandra.contact-points=cassandrahost1,cassandrahost2 @Component public class MyBean { private CassandraTemplate template; @Autowired public MyBean(CassandraTemplate template) { this.template = template; } // ... } If you add a @Bean of your own of type CassandraTemplate it will replace the default. Spring Data Cassandra repositories Spring Data includes basic repository support for Cassandra. Currently this is more limited than the JPA repositories discussed earlier, and will need to annotate finder methods with @Query. Tip For complete details of Spring Data Cassandra, refer to their reference documentation. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 107 31.8 Couchbase Couchbase is an open-source, distributed multi-model NoSQL document-oriented database that is optimized for interactive applications. Spring Boot offers auto-configuration for Couchbase and abstractions on top of it provided by Spring Data Couchbase. There is a spring-boot-starter- data-couchbase ‘Starter’ for collecting the dependencies in a convenient way. Connecting to Couchbase You can very easily get a Bucket and Cluster by adding the Couchbase SDK and some configuration. The spring.couchbase.* properties can be used to customize the connection. Generally you will provide the bootstrap hosts, bucket name and password: spring.couchbase.bootstrap-hosts=my-host-1,192.168.1.123 spring.couchbase.bucket.name=my-bucket spring.couchbase.bucket.password=secret Tip You need to provide at least the bootstrap host(s), in which case the bucket name is default and the password is the empty String. Alternatively, you can define your own org.springframework.data.couchbase.config.CouchbaseConfigurer @Bean to take control over the whole configuration. It is also possible to customize some of the CouchbaseEnvironment settings. For instance the following configuration changes the timeout to use to open a new Bucket and enables SSL support: spring.couchbase.env.timeouts.connect=3000 spring.couchbase.env.ssl.key-store=/location/of/keystore.jks spring.couchbase.env.ssl.key-store-password=secret Check the spring.couchbase.env.* properties for more details. Spring Data Couchbase repositories Spring Data includes repository support for Couchbase. For complete details of Spring Data Couchbase, refer to their reference documentation. You can inject an auto-configured CouchbaseTemplate instance as you would with any other Spring Bean as long as a default CouchbaseConfigurer is available (that happens when you enable the couchbase support as explained above). If you want to bypass the auto-configuration for Spring Data Couchbase, provide your own org.springframework.data.couchbase.config.AbstractCouchbaseDataConfiguration implementation. @Component public class MyBean { private final CouchbaseTemplate template; @Autowired public MyBean(CouchbaseTemplate template) { this.template = template; } // ... Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 108 } If you add a @Bean of your own of type CouchbaseTemplate named couchbaseTemplate it will replace the default. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 109 32. Caching The Spring Framework provides support for transparently adding caching to an application. At its core, the abstraction applies caching to methods, reducing thus the number of executions based on the information available in the cache. The caching logic is applied transparently, without any interference to the invoker. Note Check the relevant section of the Spring Framework reference for more details. In a nutshell, adding caching to an operation of your service is as easy as adding the relevant annotation to its method: import javax.cache.annotation.CacheResult; import org.springframework.stereotype.Component; @Component public class MathService { @CacheResult public int computePiDecimal(int i) { // ... } } Note You can either use the standard JSR-107 (JCache) annotations or Spring’s own caching annotations transparently. We strongly advise you however to not mix and match them. Tip It is also possible to update or evict data from the cache transparently. 32.1 Supported cache providers The cache abstraction does not provide an actual store and relies on abstraction materialized by the org.springframework.cache.Cache and org.springframework.cache.CacheManager interfaces. Spring Boot auto-configures a suitable CacheManager according to the implementation as long as the caching support is enabled via the @EnableCaching annotation. Note If you are using the cache infrastructure with beans that are not interface-based, make sure to enable the proxyTargetClass attribute of @EnableCaching. Tip Use the spring-boot-starter-cache ‘Starter’ to quickly add required caching dependencies. If you are adding dependencies manually you should note that certain implementations are only provided by the spring-context-support jar. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 110 If you haven’t defined a bean of type CacheManager or a CacheResolver named cacheResolver (see CachingConfigurer), Spring Boot tries to detect the following providers (in this order): • Generic • JCache (JSR-107) • EhCache 2.x • Hazelcast • Infinispan • Couchbase • Redis • Caffeine • Guava • Simple Tip It is also possible to force the cache provider to use via the spring.cache.type property. Use this property if you need to disable caching altogether in certain environment (e.g. tests). If the CacheManager is auto-configured by Spring Boot, you can further tune its configuration before it is fully initialized by exposing a bean implementing the CacheManagerCustomizer interface. The following sets the cache names to use. @Bean public CacheManagerCustomizer cacheManagerCustomizer() { return new CacheManagerCustomizer() { @Override public void customize(ConcurrentMapCacheManager cacheManager) { cacheManager.setCacheNames(Arrays.asList("one", "two")); } }; } Note In the example above, a ConcurrentMapCacheManager is expected to be configured. If that is not the case, the customizer won’t be invoked at all. You can have as many customizers as you want and you can also order them as usual using @Order or Ordered. Generic Generic caching is used if the context defines at least one org.springframework.cache.Cache bean, a CacheManager wrapping them is configured. JCache JCache is bootstrapped via the presence of a javax.cache.spi.CachingProvider on the classpath (i.e. a JSR-107 compliant caching library). It might happen that more than one provider is present, in which case the provider must be explicitly specified. Even if the JSR-107 standard does not Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 111 enforce a standardized way to define the location of the configuration file, Spring Boot does its best to accommodate with implementation details. # Only necessary if more than one provider is present spring.cache.jcache.provider=com.acme.MyCachingProvider spring.cache.jcache.config=classpath:acme.xml Note Since a cache library may offer both a native implementation and JSR-107 support Spring Boot will prefer the JSR-107 support so that the same features are available if you switch to a different JSR-107 implementation. There are several ways to customize the underlying javax.cache.cacheManager: • Caches can be created on startup via the spring.cache.cache-names property. If a custom javax.cache.configuration.Configuration bean is defined, it is used to customize them. • org.springframework.boot.autoconfigure.cache.JCacheManagerCustomizer beans are invoked with the reference of the CacheManager for full customization. Tip If a standard javax.cache.CacheManager bean is defined, it is wrapped automatically in a org.springframework.cache.CacheManager implementation that the abstraction expects. No further customization is applied on it. EhCache 2.x EhCache 2.x is used if a file named ehcache.xml can be found at the root of the classpath. If EhCache 2.x and such file is present it is used to bootstrap the cache manager. An alternate configuration file can be provide a well using: spring.cache.ehcache.config=classpath:config/another-config.xml Hazelcast Spring Boot has a general support for Hazelcast. If a HazelcastInstance has been auto-configured, it is automatically wrapped in a CacheManager. If for some reason you need a different HazelcastInstance for caching, you can request Spring Boot to create a separate one that will be only used by the CacheManager: spring.cache.hazelcast.config=classpath:config/my-cache-hazelcast.xml Tip If a separate HazelcastInstance is created that way, it is not registered in the application context. Infinispan Infinispan has no default configuration file location so it must be specified explicitly (or the default bootstrap is used). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 112 spring.cache.infinispan.config=infinispan.xml Caches can be created on startup via the spring.cache.cache-names property. If a custom ConfigurationBuilder bean is defined, it is used to customize them. Couchbase If Couchbase is available and configured, a CouchbaseCacheManager is auto-configured. It is also possible to create additional caches on startup using the spring.cache.cache-names property. These will operate on the Bucket that was auto-configured. You can also create additional caches on another Bucket using the customizer: assume you need two caches on the "main" Bucket (foo and bar) and one biz cache with a custom time to live of 2sec on the another Bucket. First, you can create the two first caches simply via configuration: spring.cache.cache-names=foo,bar Then define this extra @Configuration to configure the extra Bucket and the biz cache: @Configuration public class CouchbaseCacheConfiguration { private final Cluster cluster; public CouchbaseCacheConfiguration(Cluster cluster) { this.cluster = cluster; } @Bean public Bucket anotherBucket() { return this.cluster.openBucket("another", "secret"); } @Bean public CacheManagerCustomizer cacheManagerCustomizer() { return c -> { c.prepareCache("biz", CacheBuilder.newInstance(anotherBucket()) .withExpirationInMillis(2000)); }; } } This sample configuration reuses the Cluster that was created via auto-configuration. Redis If Redis is available and configured, the RedisCacheManager is auto-configured. It is also possible to create additional caches on startup using the spring.cache.cache-names property. Note By default, a key prefix is added to prevent that if two separate caches use the same key, Redis would have overlapping keys and be likely to return invalid values. We strongly recommend to keep this setting enabled if you create your own RedisCacheManager. Caffeine Caffeine is a Java 8 rewrite of Guava’s cache and will supersede the Guava support in Spring Boot 2.0. If Caffeine is present, a CaffeineCacheManager is auto-configured. Caches can be created on Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 113 startup using the spring.cache.cache-names property and customized by one of the following (in this order): 1. A cache spec defined by spring.cache.caffeine.spec 2. A com.github.benmanes.caffeine.cache.CaffeineSpec bean is defined 3. A com.github.benmanes.caffeine.cache.Caffeine bean is defined For instance, the following configuration creates a foo and bar caches with a maximum size of 500 and a time to live of 10 minutes spring.cache.cache-names=foo,bar spring.cache.caffeine.spec=maximumSize=500,expireAfterAccess=600s Besides, if a com.github.benmanes.caffeine.cache.CacheLoader bean is defined, it is automatically associated to the CaffeineCacheManager. Guava If Guava is present, a GuavaCacheManager is auto-configured. Caches can be created on startup using the spring.cache.cache-names property and customized by one of the following (in this order): 1. A cache spec defined by spring.cache.guava.spec 2. A com.google.common.cache.CacheBuilderSpec bean is defined 3. A com.google.common.cache.CacheBuilder bean is defined For instance, the following configuration creates a foo and bar caches with a maximum size of 500 and a time to live of 10 minutes spring.cache.cache-names=foo,bar spring.cache.guava.spec=maximumSize=500,expireAfterAccess=600s Besides, if a com.google.common.cache.CacheLoader bean is defined, it is automatically associated to the GuavaCacheManager. Simple If none of these options worked out, a simple implementation using ConcurrentHashMap as cache store is configured. This is the default if no caching library is present in your application. None When @EnableCaching is present in your configuration, a suitable cache configuration is expected as well. If you need to disable caching altogether in certain environments, force the cache type to none to use a no-op implementation: spring.cache.type=none Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 114 33. Messaging The Spring Framework provides extensive support for integrating with messaging systems: from simplified use of the JMS API using JmsTemplate to a complete infrastructure to receive messages asynchronously. Spring AMQP provides a similar feature set for the ‘Advanced Message Queuing Protocol’ and Spring Boot also provides auto-configuration options for RabbitTemplate and RabbitMQ. There is also support for STOMP messaging natively in Spring WebSocket and Spring Boot has support for that through starters and a small amount of auto-configuration. 33.1 JMS The javax.jms.ConnectionFactory interface provides a standard method of creating a javax.jms.Connection for interacting with a JMS broker. Although Spring needs a ConnectionFactory to work with JMS, you generally won’t need to use it directly yourself and you can instead rely on higher level messaging abstractions (see the relevant section of the Spring Framework reference documentation for details). Spring Boot also auto-configures the necessary infrastructure to send and receive messages. ActiveMQ support Spring Boot can also configure a ConnectionFactory when it detects that ActiveMQ is available on the classpath. If the broker is present, an embedded broker is started and configured automatically (as long as no broker URL is specified through configuration). Note If you are using spring-boot-starter-activemq the necessary dependencies to connect or embed an ActiveMQ instance are provided, as well as the Spring infrastructure to integrate with JMS. ActiveMQ configuration is controlled by external configuration properties in spring.activemq.*. For example, you might declare the following section in application.properties: spring.activemq.broker-url=tcp://192.168.1.210:9876 spring.activemq.user=admin spring.activemq.password=secret See ActiveMQProperties for more of the supported options. By default, ActiveMQ creates a destination if it does not exist yet, so destinations are resolved against their provided names. Artemis support Apache Artemis was formed in 2015 when HornetQ was donated to the Apache Foundation. All the features listed in the the section called “HornetQ support” section below can be applied to Artemis. Simply replace spring.hornetq.* properties with spring.artemis.* and use spring-boot- starter-artemis instead of spring-boot-starter-hornetq. If you want to embed Artemis, make sure to add org.apache.activemq:artemis-jms-server to the dependencies of your application. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 115 Note You should not try and use Artemis and HornetQ and the same time. HornetQ support Note HornetQ is deprecated in 1.4, consider migrating to artemis Spring Boot can auto-configure a ConnectionFactory when it detects that HornetQ is available on the classpath. If the broker is present, an embedded broker is started and configured automatically (unless the mode property has been explicitly set). The supported modes are: embedded (to make explicit that an embedded broker is required and should lead to an error if the broker is not available in the classpath), and native to connect to a broker using the netty transport protocol. When the latter is configured, Spring Boot configures a ConnectionFactory connecting to a broker running on the local machine with the default settings. Note If you are using spring-boot-starter-hornetq the necessary dependencies to connect to an existing HornetQ instance are provided, as well as the Spring infrastructure to integrate with JMS. Adding org.hornetq:hornetq-jms-server to your application allows you to use the embedded mode. HornetQ configuration is controlled by external configuration properties in spring.hornetq.*. For example, you might declare the following section in application.properties: spring.hornetq.mode=native spring.hornetq.host=192.168.1.210 spring.hornetq.port=9876 When embedding the broker, you can choose if you want to enable persistence, and the list of destinations that should be made available. These can be specified as a comma-separated list to create them with the default options; or you can define bean(s) of type org.hornetq.jms.server.config.JMSQueueConfiguration or org.hornetq.jms.server.config.TopicConfiguration, for advanced queue and topic configurations respectively. See HornetQProperties for more of the supported options. No JNDI lookup is involved at all and destinations are resolved against their names, either using the ‘name’ attribute in the HornetQ configuration or the names provided through configuration. Using a JNDI ConnectionFactory If you are running your application in an Application Server Spring Boot will attempt to locate a JMS ConnectionFactory using JNDI. By default the locations java:/JmsXA and java:/ XAConnectionFactory will be checked. You can use the spring.jms.jndi-name property if you need to specify an alternative location: spring.jms.jndi-name=java:/MyConnectionFactory Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 116 Sending a message Spring’s JmsTemplate is auto-configured and you can autowire it directly into your own beans: import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jms.core.JmsTemplate; import org.springframework.stereotype.Component; @Component public class MyBean { private final JmsTemplate jmsTemplate; @Autowired public MyBean(JmsTemplate jmsTemplate) { this.jmsTemplate = jmsTemplate; } // ... } Note JmsMessagingTemplate can be injected in a similar manner. If a DestinationResolver or MessageConverter beans are defined, they are associated automatically to the auto-configured JmsTemplate. Receiving a message When the JMS infrastructure is present, any bean can be annotated with @JmsListener to create a listener endpoint. If no JmsListenerContainerFactory has been defined, a default one is configured automatically. If a DestinationResolver or MessageConverter beans are defined, they are associated automatically to the default factory. The default factory is transactional by default. If you are running in an infrastructure where a JtaTransactionManager is present, it will be associated to the listener container by default. If not, the sessionTransacted flag will be enabled. In that latter scenario, you can associate your local data store transaction to the processing of an incoming message by adding @Transactional on your listener method (or a delegate thereof). This will make sure that the incoming message is acknowledged once the local transaction has completed. This also includes sending response messages that have been performed on the same JMS session. The following component creates a listener endpoint on the someQueue destination: @Component public class MyBean { @JmsListener(destination = "someQueue") public void processMessage(String content) { // ... } } Tip Check the Javadoc of @EnableJms for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 117 If you need to create more JmsListenerContainerFactory instances or if you want to override the default, Spring Boot provides a DefaultJmsListenerContainerFactoryConfigurer that you can use to initialize a DefaultJmsListenerContainerFactory with the same settings as the one that is auto-configured. For instance, the following exposes another factory that uses a specific MessageConverter: @Configuration static class JmsConfiguration { @Bean public DefaultJmsListenerContainerFactory myFactory( DefaultJmsListenerContainerFactoryConfigurer configurer) { DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory(); configurer.configure(factory, connectionFactory()); factory.setMessageConverter(myMessageConverter()); return factory; } } Then you can use in any @JmsListener-annotated method as follows: @Component public class MyBean { @JmsListener(destination = "someQueue", **containerFactory="myFactory"**) public void processMessage(String content) { // ... } } 33.2 AMQP The Advanced Message Queuing Protocol (AMQP) is a platform-neutral, wire-level protocol for message-oriented middleware. The Spring AMQP project applies core Spring concepts to the development of AMQP-based messaging solutions. Spring Boot offers several conveniences for working with AMQP via RabbitMQ, including the spring-boot-starter-amqp ‘Starter’. RabbitMQ support RabbitMQ is a lightweight, reliable, scalable and portable message broker based on the AMQP protocol. Spring uses RabbitMQ to communicate using the AMQP protocol. RabbitMQ configuration is controlled by external configuration properties in spring.rabbitmq.*. For example, you might declare the following section in application.properties: spring.rabbitmq.host=localhost spring.rabbitmq.port=5672 spring.rabbitmq.username=admin spring.rabbitmq.password=secret See RabbitProperties for more of the supported options. Tip Check Understanding AMQP, the protocol used by RabbitMQ for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 118 Sending a message Spring’s AmqpTemplate and AmqpAdmin are auto-configured and you can autowire them directly into your own beans: import org.springframework.amqp.core.AmqpAdmin; import org.springframework.amqp.core.AmqpTemplate; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; @Component public class MyBean { private final AmqpAdmin amqpAdmin; private final AmqpTemplate amqpTemplate; @Autowired public MyBean(AmqpAdmin amqpAdmin, AmqpTemplate amqpTemplate) { this.amqpAdmin = amqpAdmin; this.amqpTemplate = amqpTemplate; } // ... } Note RabbitMessagingTemplate can be injected in a similar manner. If a MessageConverter bean is defined, it is associated automatically to the auto-configured AmqpTemplate. Any org.springframework.amqp.core.Queue that is defined as a bean will be automatically used to declare a corresponding queue on the RabbitMQ instance if necessary. You can enable retries on the AmqpTemplate to retry operations, for example in the event the broker connection is lost. Retries are disabled by default. Receiving a message When the Rabbit infrastructure is present, any bean can be annotated with @RabbitListener to create a listener endpoint. If no RabbitListenerContainerFactory has been defined, a default one is configured automatically. If a MessageConverter beans is defined, it is associated automatically to the default factory. The following component creates a listener endpoint on the someQueue queue: @Component public class MyBean { @RabbitListener(queues = "someQueue") public void processMessage(String content) { // ... } } Tip Check the Javadoc of @EnableRabbit for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 119 If you need to create more RabbitListenerContainerFactory instances or if you want to override the default, Spring Boot provides a SimpleRabbitListenerContainerFactoryConfigurer that you can use to initialize a SimpleRabbitListenerContainerFactory with the same settings as the one that is auto-configured. For instance, the following exposes another factory that uses a specific MessageConverter: @Configuration static class RabbitConfiguration { @Bean public SimpleRabbitListenerContainerFactory myFactory( SimpleRabbitListenerContainerFactoryConfigurer configurer) { SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory(); configurer.configure(factory, connectionFactory); factory.setMessageConverter(myMessageConverter()); return factory; } } Then you can use in any @RabbitListener-annotated method as follows: @Component public class MyBean { @RabbitListener(queues = "someQueue", **containerFactory="myFactory"**) public void processMessage(String content) { // ... } } You can enable retries to handle situations where your listener throws an exception. When retries are exhausted, the message will be rejected and either dropped or routed to a dead-letter exchange if the broker is configured so. Retries are disabled by default. Important If retries are not enabled and the listener throws an exception, by default the delivery will be retried indefinitely. You can modify this behavior in two ways; set the defaultRequeueRejected property to false and zero re-deliveries will be attempted; or, throw an AmqpRejectAndDontRequeueException to signal the message should be rejected. This is the mechanism used when retries are enabled and the maximum delivery attempts are reached. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 120 34. Calling REST services If you need to call remote REST services from your application, you can use Spring Framework’s RestTemplate class. Since RestTemplate instances often needs to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean. It does, however, auto-configure a RestTemplateBuilder which can be used to create RestTemplate instances when needed. The auto-configured RestTemplateBuilder will ensure that sensible HttpMessageConverters are applied to RestTemplate instances. Here’s a typical example: @Service public class MyBean { private final RestTemplate restTemplate; public MyBean(RestTemplateBuilder restTemplateBuilder) { this.restTemplate = restTemplateBuilder.build(); } public String someRestCall(String name) { return this.restTemplate.getForObject("/{name}/details", Details.class, name); } } Tip RestTemplateBuilder includes a number of useful methods that can be used to quickly configure a RestTemplate. For example, to add BASIC auth support you can use build.basicAuthorization("user', "password").build(). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 121 35. Sending email The Spring Framework provides an easy abstraction for sending email using the JavaMailSender interface and Spring Boot provides auto-configuration for it as well as a starter module. Tip Check the reference documentation for a detailed explanation of how you can use JavaMailSender. If spring.mail.host and the relevant libraries (as defined by spring-boot-starter-mail) are available, a default JavaMailSender is created if none exists. The sender can be further customized by configuration items from the spring.mail namespace, see the MailProperties for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 122 36. Distributed Transactions with JTA Spring Boot supports distributed JTA transactions across multiple XA resources using either an Atomikos or Bitronix embedded transaction manager. JTA transactions are also supported when deploying to a suitable Java EE Application Server. When a JTA environment is detected, Spring’s JtaTransactionManager will be used to manage transactions. Auto-configured JMS, DataSource and JPA beans will be upgraded to support XA transactions. You can use standard Spring idioms such as @Transactional to participate in a distributed transaction. If you are within a JTA environment and still want to use local transactions you can set the spring.jta.enabled property to false to disable the JTA auto-configuration. 36.1 Using an Atomikos transaction manager Atomikos is a popular open source transaction manager which can be embedded into your Spring Boot application. You can use the spring-boot-starter-jta-atomikos Starter to pull in the appropriate Atomikos libraries. Spring Boot will auto-configure Atomikos and ensure that appropriate depends-on settings are applied to your Spring beans for correct startup and shutdown ordering. By default Atomikos transaction logs will be written to a transaction-logs directory in your application home directory (the directory in which your application jar file resides). You can customize this directory by setting a spring.jta.log-dir property in your application.properties file. Properties starting spring.jta.atomikos.properties can also be used to customize the Atomikos UserTransactionServiceImp. See the AtomikosProperties Javadoc for complete details. Note To ensure that multiple transaction managers can safely coordinate the same resource managers, each Atomikos instance must be configured with a unique ID. By default this ID is the IP address of the machine on which Atomikos is running. To ensure uniqueness in production, you should configure the spring.jta.transaction-manager-id property with a different value for each instance of your application. 36.2 Using a Bitronix transaction manager Bitronix is popular open source JTA transaction manager implementation. You can use the spring- boot-starter-jta-bitronix starter to add the appropriate Bitronix dependencies to your project. As with Atomikos, Spring Boot will automatically configure Bitronix and post-process your beans to ensure that startup and shutdown ordering is correct. By default Bitronix transaction log files (part1.btm and part2.btm) will be written to a transaction-logs directory in your application home directory. You can customize this directory by using the spring.jta.log-dir property. Properties starting spring.jta.bitronix.properties are also bound to the bitronix.tm.Configuration bean, allowing for complete customization. See the Bitronix documentation for details. Note To ensure that multiple transaction managers can safely coordinate the same resource managers, each Bitronix instance must be configured with a unique ID. By default this ID is the IP address Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 123 of the machine on which Bitronix is running. To ensure uniqueness in production, you should configure the spring.jta.transaction-manager-id property with a different value for each instance of your application. 36.3 Using a Narayana transaction manager Narayana is popular open source JTA transaction manager implementation supported by JBoss. You can use the spring-boot-starter-jta-narayana starter to add the appropriate Narayana dependencies to your project. As with Atomikos and Bitronix, Spring Boot will automatically configure Narayana and post-process your beans to ensure that startup and shutdown ordering is correct. By default Narayana transaction logs will be written to a transaction-logs directory in your application home directory (the directory in which your application jar file resides). You can customize this directory by setting a spring.jta.log-dir property in your application.properties file. Properties starting spring.jta.narayana.properties can also be used to customize the Narayana configuration. See the NarayanaProperties Javadoc for complete details. Note To ensure that multiple transaction managers can safely coordinate the same resource managers, each Narayana instance must be configured with a unique ID. By default this ID is set to 1. To ensure uniqueness in production, you should configure the spring.jta.transaction- manager-id property with a different value for each instance of your application. 36.4 Using a Java EE managed transaction manager If you are packaging your Spring Boot application as a war or ear file and deploying it to a Java EE application server, you can use your application servers built-in transaction manager. Spring Boot will attempt to auto-configure a transaction manager by looking at common JNDI locations (java:comp/UserTransaction, java:comp/TransactionManager etc). If you are using a transaction service provided by your application server, you will generally also want to ensure that all resources are managed by the server and exposed over JNDI. Spring Boot will attempt to auto-configure JMS by looking for a ConnectionFactory at the JNDI path java:/JmsXA or java:/XAConnectionFactory and you can use the spring.datasource.jndi-name property to configure your DataSource. 36.5 Mixing XA and non-XA JMS connections When using JTA, the primary JMS ConnectionFactory bean will be XA aware and participate in distributed transactions. In some situations you might want to process certain JMS messages using a non-XA ConnectionFactory. For example, your JMS processing logic might take longer than the XA timeout. If you want to use a non-XA ConnectionFactory you can inject the nonXaJmsConnectionFactory bean rather than the @Primary jmsConnectionFactory bean. For consistency the jmsConnectionFactory bean is also provided using the bean alias xaJmsConnectionFactory. For example: // Inject the primary (XA aware) ConnectionFactory @Autowired private ConnectionFactory defaultConnectionFactory; Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 124 // Inject the XA aware ConnectionFactory (uses the alias and injects the same as above) @Autowired @Qualifier("xaJmsConnectionFactory") private ConnectionFactory xaConnectionFactory; // Inject the non-XA aware ConnectionFactory @Autowired @Qualifier("nonXaJmsConnectionFactory") private ConnectionFactory nonXaConnectionFactory; 36.6 Supporting an alternative embedded transaction manager The XAConnectionFactoryWrapper and XADataSourceWrapper interfaces can be used to support alternative embedded transaction managers. The interfaces are responsible for wrapping XAConnectionFactory and XADataSource beans and exposing them as regular ConnectionFactory and DataSource beans which will transparently enroll in the distributed transaction. DataSource and JMS auto-configuration will use JTA variants as long as you have a JtaTransactionManager bean and appropriate XA wrapper beans registered within your ApplicationContext. The BitronixXAConnectionFactoryWrapper and BitronixXADataSourceWrapper provide good examples of how to write XA wrappers. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 125 37. Hazelcast If hazelcast is on the classpath, Spring Boot will auto-configure an HazelcastInstance that you can inject in your application. The HazelcastInstance is only created if a configuration is found. You can define a com.hazelcast.config.Config bean and we’ll use that. If your configuration defines an instance name, we’ll try to locate an existing instance rather than creating a new one. You could also specify the hazelcast.xml configuration file to use via configuration: spring.hazelcast.config=classpath:config/my-hazelcast.xml Otherwise, Spring Boot tries to find the Hazelcast configuration from the default locations, that is hazelcast.xml in the working directory or at the root of the classpath. We also check if the hazelcast.config system property is set. Check the Hazelcast documentation for more details. Note Spring Boot also has an explicit caching support for Hazelcast. The HazelcastInstance is automatically wrapped in a CacheManager implementation if caching is enabled. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 126 38. Spring Integration Spring Boot offers several conveniences for working with Spring Integration, including the spring- boot-starter-integration ‘Starter’. Spring Integration provides abstractions over messaging and also other transports such as HTTP, TCP etc. If Spring Integration is available on your classpath it will be initialized through the @EnableIntegration annotation. Message processing statistics will be published over JMX if 'spring-integration-jmx' is also on the classpath. See the IntegrationAutoConfiguration class for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 127 39. Spring Session Spring Boot provides Spring Session auto-configuration for a wide range of stores: • JDBC • MongoDB • Redis • Hazelcast • HashMap If Spring Session is available, you only need to choose the StoreType that you wish to use to store the sessions. For instance to use Redis as backend store, you’d configure your application as follows: spring.session.store-type=redis Each store has specific additional settings. For instance it is possible to customize the name of the table for the jdbc store: spring.session.jdbc.table-name=SESSIONS Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 128 40. Monitoring and management over JMX Java Management Extensions (JMX) provide a standard mechanism to monitor and manage applications. By default Spring Boot will create an MBeanServer with bean id ‘mbeanServer’ and expose any of your beans that are annotated with Spring JMX annotations (@ManagedResource, @ManagedAttribute, @ManagedOperation). See the JmxAutoConfiguration class for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 129 41. Testing Spring Boot provides a number of utilities and annotations to help when testing your application. Test support is provided by two modules; spring-boot-test contains core items, and spring-boot- test-autoconfigure supports auto-configuration for tests. Most developers will just use the spring-boot-starter-test ‘Starter’ which imports both Spring Boot test modules as well has JUnit, AssertJ, Hamcrest and a number of other useful libraries. 41.1 Test scope dependencies If you use the spring-boot-starter-test ‘Starter’ (in the test scope), you will find the following provided libraries: • JUnit — The de-facto standard for unit testing Java applications. • Spring Test & Spring Boot Test — Utilities and integration test support for Spring Boot applications. • AssertJ — A fluent assertion library. • Hamcrest — A library of matcher objects (also known as constraints or predicates). • Mockito — A Java mocking framework. • JSONassert — An assertion library for JSON. • JsonPath — XPath for JSON. These are common libraries that we generally find useful when writing tests. You are free to add additional test dependencies of your own if these don’t suit your needs. 41.2 Testing Spring applications One of the major advantages of dependency injection is that it should make your code easier to unit test. You can simply instantiate objects using the new operator without even involving Spring. You can also use mock objects instead of real dependencies. Often you need to move beyond ‘unit testing’ and start ‘integration testing’ (with a Spring ApplicationContext actually involved in the process). It’s useful to be able to perform integration testing without requiring deployment of your application or needing to connect to other infrastructure. The Spring Framework includes a dedicated test module for just such integration testing. You can declare a dependency directly to org.springframework:spring-test or use the spring-boot- starter-test ‘Starter’ to pull it in transitively. If you have not used the spring-test module before you should start by reading the relevant section of the Spring Framework reference documentation. 41.3 Testing Spring Boot applications A Spring Boot application is just a Spring ApplicationContext, so nothing very special has to be done to test it beyond what you would normally do with a vanilla Spring context. One thing to watch out Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 130 for though is that the external properties, logging and other features of Spring Boot are only installed in the context by default if you use SpringApplication to create it. Spring Boot provides a @SpringBootTest annotation which can be used as an alternative to the standard spring-test @ContextConfiguration annotation when you need Spring Boot features. The annotation works by creating the ApplicationContext used in your tests via SpringApplication. You can use the webEnvironment attribute of @SpringBootTest to further refine how your tests will run: • MOCK — Loads a WebApplicationContext and provides a mock servlet environment. Embedded servlet containers are not started when using this annotation. If servlet APIs are not on your classpath this mode will transparently fallback to creating a regular non-web ApplicationContext. • RANDOM_PORT — Loads an EmbeddedWebApplicationContext and provides a real servlet environment. Embedded servlet containers are started and listening on a random port. • DEFINED_PORT — Loads an EmbeddedWebApplicationContext and provides a real servlet environment. Embedded servlet containers are started and listening on a defined port (i.e from your application.properties or on the default port 8080). • NONE — Loads an ApplicationContext using SpringApplication but does not provide any servlet environment (mock or otherwise). Note In addition to @SpringBootTest a number of other annotations are also provided for testing more specific slices of an application. See below for details. Tip Don’t forget to also add @RunWith(SpringRunner.class) to your test, otherwise the annotations will be ignored. Detecting test configuration If you’re familiar with the Spring Test Framework, you may be used to using @ContextConfiguration(classes=…) in order to specify which Spring @Configuration to load. Alternatively, you might have often used nested @Configuration classes within your test. When testing Spring Boot applications this is often not required. Spring Boot’s @*Test annotations will search for your primary configuration automatically whenever you don’t explicitly define one. The search algorithm works up from the package that contains the test until it finds a @SpringBootApplication or @SpringBootConfiguration annotated class. As long as you’ve structure your code in a sensible way your main configuration is usually found. If you want to customize the primary configuration, you can use a nested @TestConfiguration class. Unlike a nested @Configuration class which would be used instead of a your application’s primary configuration, a nested @TestConfiguration class will be used in addition to your application’s primary configuration. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 131 Note Spring’s test framework will cache application contexts between tests. Therefore, as long as your tests share the same configuration (no matter how it’s discovered), the potentially time consuming process of loading the context will only happen once. Excluding test configuration If your application uses component scanning, for example if you use @SpringBootApplication or @ComponentScan, you may find components or configurations created only for specific tests accidentally get picked up everywhere. To help prevent this, Spring Boot provides @TestComponent and @TestConfiguration annotations that can be used on classes in src/test/java to indicate that they should not be picked up by scanning. Note @TestComponent and @TestConfiguration are only needed on top level classes. If you define @Configuration or @Component as inner-classes within a test, they will be automatically filtered. Note If you directly use @ComponentScan (i.e. not via @SpringBootApplication) you will need to register the TypeExcludeFilter with it. See the Javadoc for details. Working with random ports If you need to start a full running server for tests, we recommend that you use random ports. If you use @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) an available port will be picked at random each time your test runs. The @LocalServerPort annotation can be used to inject the actual port used into your test. For convenience, tests that need to make REST calls to the started server can additionally @Autowire a TestRestTemplate which will resolve relative links to the running server. import org.junit.*; import org.junit.runner.*; import org.springframework.boot.test.context.web.*; import org.springframework.boot.test.web.client.*; import org.springframework.test.context.junit4.*; import static org.assertj.core.api.Assertions.* @RunWith(SpringRunner.class) @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) public class MyWebIntegrationTests { @Autowired private TestRestTemplate restTemplate; @Test public void exampleTest() { String body = this.restTemplate.getForObject("/", String.class); assertThat(body).isEqualTo("Hello World"); } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 132 } Mocking and spying beans It’s sometimes necessary to mock certain components within your application context when running tests. For example, you may have a facade over some remote service that’s unavailable during development. Mocking can also be useful when you want to simulate failures that might be hard to trigger in a real environment. Spring Boot includes a @MockBean annotation that can be used to define a Mockito mock for a bean inside your ApplicationContext. You can use the annotation to add new beans, or replace a single existing bean definition. The annotation can be used directly on test classes, on fields within your test, or on @Configuration classes and fields. When used on a field, the instance of the created mock will also be injected. Mock beans are automatically reset after each test method. Here’s a typical example where we replace an existing RemoteService bean with a mock implementation: import org.junit.*; import org.junit.runner.*; import org.springframework.beans.factory.annotation.*; import org.springframework.boot.test.context.*; import org.springframework.boot.test.mock.mockito.*; import org.springframework.test.context.junit4.*; import static org.assertj.core.api.Assertions.*; import static org.mockito.BDDMockito.*; @RunWith(SpringRunner.class) @SpringBootTest public class MyTests { @MockBean private RemoteService remoteService; @Autowired private Reverser reverser; @Test public void exampleTest() { // RemoteService has been injected into the reverser bean given(this.remoteService.someCall()).willReturn("mock"); String reverse = reverser.reverseSomeCall(); assertThat(reverse).isEqualTo("kcom"); } } Additionally you can also use @SpyBean to wrap any existing bean with a Mockito spy. See the Javadoc for full details. Auto-configured tests Spring Boot’s auto-configuration system works well for applications, but can sometimes be a little too much for tests. It’s often helpful to load only the parts of the configuration that are required to test a ‘slice’ of your application. For example, you might want to test that Spring MVC controllers are mapping URLs correctly, and you don’t want to involve database calls in those tests; or you might be wanting to test JPA entities, and you’re not interested in web layer when those tests run. The spring-boot-test-autoconfigure module includes a number of annotations that can be used to automatically configure such ‘slices’. Each of them works in a similar way, providing a @…Test Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 133 annotation that loads the ApplicationContext and one or more @AutoConfigure… annotations that can be used to customize auto-configuration settings. Tip It’s also possible to use the @AutoConfigure… annotations with the standard @SpringBootTest annotation. You can use this combination if you’re not interested in ‘slicing’ your application but you want some of the auto-configured test beans. Auto-configured JSON tests To test that Object JSON serialization and deserialization is working as expected you can use the @JsonTest annotation. @JsonTest will auto-configure Jackson ObjectMapper, any @JsonComponent beans and any Jackson Modules. It also configures Gson if you happen to be using that instead of, or as well as, Jackson. If you need to configure elements of the auto-configuration you can use the @AutoConfigureJsonTesters annotation. Spring Boot includes AssertJ based helpers that work with the JSONassert and JsonPath libraries to check that JSON is as expected. The JacksonHelper, GsonHelper and BasicJsonTester classes can be used for Jackson, Gson and Strings respectively. Any helper fields on the test class will be automatically initialized when using @JsonTest. import org.junit.*; import org.junit.runner.*; import org.springframework.boot.test.autoconfigure.json.*; import org.springframework.boot.test.context.*; import org.springframework.boot.test.json.*; import org.springframework.test.context.junit4.*; import static org.assertj.core.api.Assertions.*; @RunWith(SpringRunner.class) @JsonTest public class MyJsonTests { private JacksonTester json; @Test public void testSerialize() throws Exception { VehicleDetails details = new VehicleDetails("Honda", "Civic"); // Assert against a `.json` file in the same package as the test assertThat(this.json.write(details)).isEqualToJson("expected.json"); // Or use JSON path based assertions assertThat(this.json.write(details)).hasJsonPathStringValue("@.make"); assertThat(this.json.write(details)).extractingJsonPathStringValue("@.make") .isEqualTo("Honda"); } @Test public void testDeserialize() throws Exception { String content = "{\"make\":\"Ford\",\"model\":\"Focus\"}"; assertThat(this.json.parse(content)) .isEqualTo(new VehicleDetails("Ford", "Focus")); assertThat(this.json.parseObject(content).getMake()).isEqualTo("Ford"); } } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 134 Note JSON helper classes can also be used directly in standard unit tests. Simply call the initFields method of the helper in your @Before method if you aren’t using @JsonTest. Auto-configured Spring MVC tests To test Spring MVC controllers are working as expected you can use the @WebMvcTest annotation. @WebMvcTest will auto-configure the Spring MVC infrastructure and limit scanned beans to @Controller, @ControllerAdvice, @JsonComponent, Filter, WebMvcConfigurer and HandlerMethodArgumentResolver. Regular @Component beans will not be scanned when using this annotation. Often @WebMvcTest will be limited to a single controller and used in combination with @MockBean to provide mock implementations for required collaborators. @WebMvcTest is meta-annotated with @AutoConfigureMockMvc which provides auto-configuration of MockMvc. Mock MVC offers a powerful way to quickly test MVC controllers without needing to start a full HTTP server. import org.junit.*; import org.junit.runner.*; import org.springframework.beans.factory.annotation.*; import org.springframework.boot.test.autoconfigure.web.servlet.*; import org.springframework.boot.test.mock.mockito.*; import static org.assertj.core.api.Assertions.*; import static org.mockito.BDDMockito.*; import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*; import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*; @RunWith(SpringRunner.class) @WebMvcTest(UserVehicleController.class) public class MyControllerTests { @Autowired private MockMvc mvc; @MockBean private UserVehicleService userVehicleService; @Test public void testExample() throws Exception { given(this.userVehicleService.getVehicleDetails("sboot")) .willReturn(new VehicleDetails("Honda", "Civic")); this.mvc.perform(get("/sboot/vehicle").accept(MediaType.TEXT_PLAIN)) .andExpect(status().isOk()).andExpect(content().string("Honda Civic")); } } Tip If you need to configure elements of the auto-configuration (for example when servlet filters should be applied) you can use attributes in the @AutoConfigureMockMvc annotation. If you use HtmlUnit or Selenium, auto-configuration will also provide a WebClient bean and/or a WebDriver bean. Here is an example that uses HtmlUnit: import com.gargoylesoftware.htmlunit.*; import org.junit.*; Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 135 import org.junit.runner.*; import org.springframework.beans.factory.annotation.*; import org.springframework.boot.test.autoconfigure.web.servlet.*; import org.springframework.boot.test.mock.mockito.*; import static org.assertj.core.api.Assertions.*; import static org.mockito.BDDMockito.*; @RunWith(SpringRunner.class) @WebMvcTest(UserVehicleController.class) public class MyHtmlUnitTests { @Autowired private WebClient webClient; @MockBean private UserVehicleService userVehicleService; @Test public void testExample() throws Exception { given(this.userVehicleService.getVehicleDetails("sboot")) .willReturn(new VehicleDetails("Honda", "Civic")); HtmlPage page = this.webClient.getPage("/sboot/vehicle.html"); assertThat(page.getBody().getTextContent()).isEqualTo("Honda Civic"); } } Auto-configured Data JPA tests @DataJpaTest can be used if you want to test JPA applications. By default it will configure an in- memory embedded database, scan for @Entity classes and configure Spring Data JPA repositories. Regular @Component beans will not be loaded into the ApplicationContext. Data JPA tests are transactional and rollback at the end of each test by default, see the docs.spring.io/spring/docs/4.3.0.RELEASE/spring-framework-reference/htmlsingle#testcontext-tx- enabling-transactions [relevant section] in the Spring Reference Documentation for more details. If that’s not what you want, you can disable transaction management for a test or for the whole class as follows: import org.junit.*; import org.junit.runner.*; import org.springframework.boot.test.autoconfigure.orm.jpa.*; import org.springframework.test.context.transaction.TestTransaction; import org.springframework.transaction.annotation.Propagation; @RunWith(SpringRunner.class) @DataJpaTest @Transactional(propagation = Propagation.NOT_SUPPORTED) public class ExampleNonTransactionalTests { } Data JPA tests may also inject a TestEntityManager bean which provides an alternative to the standard JPA EntityManager specifically designed for tests. If you want to use TestEntityManager outside of @DataJpaTests you can also use the @AutoConfigureTestEntityManager annotation. import org.junit.*; import org.junit.runner.*; import org.springframework.boot.test.autoconfigure.orm.jpa.*; import static org.assertj.core.api.Assertions.*; @RunWith(SpringRunner.class) @DataJpaTest Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 136 public class ExampleRepositoryTests { @Autowired private TestEntityManager entityManager; @Autowired private UserRepository repository; @Test public void testExample() throws Exception { this.entityManager.persist(new User("sboot", "1234")); User user = this.repository.findByUsername("sboot"); assertThat(user.getUsername()).isEqualTo("sboot"); assertThat(user.getVin()).isEqualTo("1234"); } } In-memory embedded databases generally work well for tests since they are fast and don’t require any developer installation. If, however, you prefer to run tests against a real database you can use the @AutoConfigureTestDatabase annotation: @RunWith(SpringRunner.class) @DataJpaTest @AutoConfigureTestDatabase(replace=Replace.NONE) public class ExampleRepositoryTests { // ... } Auto-configured REST clients Use @RestClientTest annotation can be used if you want to test REST clients. By default it will auto configure Jackson and GSON support, configure a RestTemplateBuilder and add support for MockRestServiceServer. The specific beans that you want to test should be specified using value or components attribute of @RestClientTest: @RunWith(SpringRunner.class) @RestClientTest(RemoteVehicleDetailsService.class) public class ExampleRestClientTest { @Autowired private MyService service; @Autowired private MockRestServiceServer server; @Test public void getVehicleDetailsWhenResultIsSuccessShouldReturnDetails() throws Exception { this.server.expect(requestTo("/greet/details")) .andRespond(withSuccess("hello", MediaType.TEXT_PLAIN)); String greeting = this.service.callRestService(); assertThat(greeting).isEqualTo("hello"); } } Auto-configured Spring REST Docs tests The @AutoConfigureRestDocs annotation can be used if you want to use Spring REST Docs in your tests. It will automatically configure MockMvc to use Spring REST Docs and remove the need for Spring REST Docs' JUnit rule. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 137 import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest; import org.springframework.http.MediaType; import org.springframework.test.context.junit4.SpringRunner; import org.springframework.test.web.servlet.MockMvc; import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.document; import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get; import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*; @RunWith(SpringRunner.class) @WebMvcTest(UserController.class) @AutoConfigureRestDocs("target/generated-snippets") public class UserDocumentationTests { @Autowired private MockMvc mvc; @Test public void listUsers() throws Exception { this.mvc.perform(get("/users").accept(MediaType.TEXT_PLAIN)) .andExpect(status().isOk()) .andDo(document("list-users")); } } In addition to configuring the output directory, @AutoConfigureRestDocs can also configure the host, scheme, and port that will appear in any documented URIs. If you require more control over Spring REST Docs' configuration a RestDocsMockMvcConfigurationCustomizer bean can be used: @TestConfiguration static class CustomizationConfiguration implements RestDocsMockMvcConfigurationCustomizer { @Override public void customize(MockMvcRestDocumentationConfigurer configurer) { configurer.snippets().withTemplateFormat(TemplateFormats.markdown()); } } If you want to make use of Spring REST Docs' support for a parameterized output directory, you can create a RestDocumentationResultHandler bean. The auto-configuration will call alwaysDo with this result handler, thereby causing each MockMvc call to automatically generate the default snippets: @TestConfiguration static class ResultHandlerConfiguration { @Bean public RestDocumentationResultHandler restDocumentation() { return MockMvcRestDocumentation.document("{method-name}"); } } Using Spock to test Spring Boot applications If you wish to use Spock to test a Spring Boot application you should add a dependency on Spock’s spock-spring module to your application’s build. spock-spring integrates Spring’s test framework into Spock. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 138 Note The annotations described above can be used with Spock, i.e. you can annotate your Specification with @SpringBootTest to suit the needs of your tests. 41.4 Test utilities A few test utility classes are packaged as part of spring-boot that are generally useful when testing your application. ConfigFileApplicationContextInitializer ConfigFileApplicationContextInitializer is an ApplicationContextInitializer that can apply to your tests to load Spring Boot application.properties files. You can use this when you don’t need the full features provided by @SpringBootTest. @ContextConfiguration(classes = Config.class, initializers = ConfigFileApplicationContextInitializer.class) EnvironmentTestUtils EnvironmentTestUtils allows you to quickly add properties to a ConfigurableEnvironment or ConfigurableApplicationContext. Simply call it with key=value strings: EnvironmentTestUtils.addEnvironment(env, "org=Spring", "name=Boot"); OutputCapture OutputCapture is a JUnit Rule that you can use to capture System.out and System.err output. Simply declare the capture as a @Rule then use toString() for assertions: import org.junit.Rule; import org.junit.Test; import org.springframework.boot.test.rule.OutputCapture; import static org.hamcrest.Matchers.*; import static org.junit.Assert.*; public class MyTest { @Rule public OutputCapture capture = new OutputCapture(); @Test public void testName() throws Exception { System.out.println("Hello World!"); assertThat(capture.toString(), containsString("World")); } } TestRestTemplate TestRestTemplate is a convenience alternative to Spring’s RestTemplate that is useful in integration tests. You can get a vanilla template or one that sends Basic HTTP authentication (with a username and password). In either case the template will behave in a test-friendly way: not following redirects (so you can assert the response location), ignoring cookies (so the template is stateless), and not throwing exceptions on server-side errors. It is recommended, but not mandatory, to use Apache Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 139 HTTP Client (version 4.3.2 or better), and if you have that on your classpath the TestRestTemplate will respond by configuring the client appropriately. public class MyTest { private TestRestTemplate template = new TestRestTemplate(); @Test public void testRequest() throws Exception { HttpHeaders headers = template.getForEntity("http://myhost.com", String.class).getHeaders(); assertThat(headers.getLocation().toString(), containsString("myotherhost")); } } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 140 42. WebSockets Spring Boot provides WebSockets auto-configuration for embedded Tomcat (8 and 7), Jetty 9 and Undertow. If you’re deploying a war file to a standalone container, Spring Boot assumes that the container will be responsible for the configuration of its WebSocket support. Spring Framework provides rich WebSocket support that can be easily accessed via the spring- boot-starter-websocket module. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 141 43. Web Services Spring Boot provides Web Services auto-configuration so that all is required is defining your Endpoints. The Spring Web Services features can be easily accessed via the spring-boot-starter- webservices module. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 142 44. Creating your own auto-configuration If you work in a company that develops shared libraries, or if you work on an open-source or commercial library, you might want to develop your own auto-configuration. Auto-configuration classes can be bundled in external jars and still be picked-up by Spring Boot. Auto-configuration can be associated to a "starter" that provides the auto-configuration code as well as the typical libraries that you would use with it. We will first cover what you need to know to build your own auto-configuration and we will move on to the typical steps required to create a custom starter. Tip A demo project is available to showcase how you can create a starter step by step. 44.1 Understanding auto-configured beans Under the hood, auto-configuration is implemented with standard @Configuration classes. Additional @Conditional annotations are used to constrain when the auto-configuration should apply. Usually auto-configuration classes use @ConditionalOnClass and @ConditionalOnMissingBean annotations. This ensures that auto-configuration only applies when relevant classes are found and when you have not declared your own @Configuration. You can browse the source code of spring-boot-autoconfigure to see the @Configuration classes that we provide (see the META-INF/spring.factories file). 44.2 Locating auto-configuration candidates Spring Boot checks for the presence of a META-INF/spring.factories file within your published jar. The file should list your configuration classes under the EnableAutoConfiguration key. org.springframework.boot.autoconfigure.EnableAutoConfiguration=\ com.mycorp.libx.autoconfigure.LibXAutoConfiguration,\ com.mycorp.libx.autoconfigure.LibXWebAutoConfiguration You can use the @AutoConfigureAfter or @AutoConfigureBefore annotations if your configuration needs to be applied in a specific order. For example, if you provide web-specific configuration, your class may need to be applied after WebMvcAutoConfiguration. If you want to order certain auto-configurations that shouldn’t have any direct knowledge of each other, you can also use @AutoconfigureOrder. That annotation has the same semantic as the regular @Order annotation but provides a dedicated order for auto-configuration classes. Note Auto-configurations have to be loaded that way only. Make sure that they are defined in a specific package space and that they are never the target of component scan in particular. 44.3 Condition annotations You almost always want to include one or more @Conditional annotations on your auto-configuration class. The @ConditionalOnMissingBean is one common example that is used to allow developers to ‘override’ auto-configuration if they are not happy with your defaults. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 143 Spring Boot includes a number of @Conditional annotations that you can reuse in your own code by annotating @Configuration classes or individual @Bean methods. Class conditions The @ConditionalOnClass and @ConditionalOnMissingClass annotations allows configuration to be included based on the presence or absence of specific classes. Due to the fact that annotation metadata is parsed using ASM you can actually use the value attribute to refer to the real class, even though that class might not actually appear on the running application classpath. You can also use the name attribute if you prefer to specify the class name using a String value. Bean conditions The @ConditionalOnBean and @ConditionalOnMissingBean annotations allow a bean to be included based on the presence or absence of specific beans. You can use the value attribute to specify beans by type, or name to specify beans by name. The search attribute allows you to limit the ApplicationContext hierarchy that should be considered when searching for beans. Tip You need to be very careful about the order that bean definitions are added as these conditions are evaluated based on what has been processed so far. For this reason, we recommend only using @ConditionalOnBean and @ConditionalOnMissingBean annotations on auto- configuration classes (since these are guaranteed to load after any user-define beans definitions have been added). Note @ConditionalOnBean and @ConditionalOnMissingBean do not prevent @Configuration classes from being created. Using these conditions at the class level is equivalent to marking each contained @Bean method with the annotation. Property conditions The @ConditionalOnProperty annotation allows configuration to be included based on a Spring Environment property. Use the prefix and name attributes to specify the property that should be checked. By default any property that exists and is not equal to false will be matched. You can also create more advanced checks using the havingValue and matchIfMissing attributes. Resource conditions The @ConditionalOnResource annotation allows configuration to be included only when a specific resource is present. Resources can be specified using the usual Spring conventions, for example, file:/home/user/test.dat. Web application conditions The @ConditionalOnWebApplication and @ConditionalOnNotWebApplication annotations allow configuration to be included depending on whether the application is a 'web application'. A web application is any application that is using a Spring WebApplicationContext, defines a session scope or has a StandardServletEnvironment. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 144 SpEL expression conditions The @ConditionalOnExpression annotation allows configuration to be included based on the result of a SpEL expression. 44.4 Creating your own starter A full Spring Boot starter for a library may contain the following components: • The autoconfigure module that contains the auto-configuration code. • The starter module that provides a dependency to the autoconfigure module as well as the library and any additional dependencies that are typically useful. In a nutshell, adding the starter should be enough to start using that library. Tip You may combine the auto-configuration code and the dependency management in a single module if you don’t need to separate those two concerns. Naming Please make sure to provide a proper namespace for your starter. Do not start your module names with spring-boot, even if you are using a different Maven groupId. We may offer an official support for the thing you’re auto-configuring in the future. Here is a rule of thumb. Let’s assume that you are creating a starter for "acme", name the auto-configure module acme-spring-boot-autoconfigure and the starter acme-spring-boot-starter. If you only have one module combining the two, use acme-spring-boot-starter. Besides, if your starter provides configuration keys, use a proper namespace for them. In particular, do not include your keys in the namespaces that Spring Boot uses (e.g. server, management, spring, etc). These are "ours" and we may improve/modify them in the future in such a way it could break your things. Make sure to trigger meta-data generation so that IDE assistance is available for your keys as well. You may want to review the generated meta-data (META-INF/spring-configuration- metadata.json) to make sure your keys are properly documented. Autoconfigure module The autoconfigure module contains everything that is necessary to get started with the library. It may also contain configuration keys definition (@ConfigurationProperties) and any callback interface that can be used to further customize how the components are initialized. Tip You should mark the dependencies to the library as optional so that you can include the autoconfigure module in your projects more easily. If you do it that way, the library won’t be provided and Spring Boot will back off by default. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 145 Starter module The starter is an empty jar, really. Its only purpose is to provide the necessary dependencies to work with the library; see it as an opinionated view of what is required to get started. Do not make assumptions about the project in which your starter is added. If the library you are auto- configuring typically requires other starters, mention them as well. Providing a proper set of default dependencies may be hard if the number of optional dependencies is high as you should avoid bringing unnecessary dependencies for a typical usage of the library. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 146 45. What to read next If you want to learn more about any of the classes discussed in this section you can check out the Spring Boot API documentation or you can browse the source code directly. If you have specific questions, take a look at the how-to section. If you are comfortable with Spring Boot’s core features, you can carry on and read about production- ready features. Part V. Spring Boot Actuator: Production-ready features Spring Boot includes a number of additional features to help you monitor and manage your application when it’s pushed to production. You can choose to manage and monitor your application using HTTP endpoints, with JMX or even by remote shell (SSH or Telnet). Auditing, health and metrics gathering can be automatically applied to your application. Actuator HTTP endpoints are only available with a Spring MVC-based application. In particular, it will not work with Jersey unless you enable Spring MVC as well. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 148 46. Enabling production-ready features The spring-boot-actuator module provides all of Spring Boot’s production-ready features. The simplest way to enable the features is to add a dependency to the spring-boot-starter-actuator ‘Starter’. Definition of Actuator An actuator is a manufacturing term, referring to a mechanical device for moving or controlling something. Actuators can generate a large amount of motion from a small change. To add the actuator to a Maven based project, add the following ‘Starter’ dependency: org.springframework.boot spring-boot-starter-actuator For Gradle, use the declaration: dependencies { compile("org.springframework.boot:spring-boot-starter-actuator") } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 149 47. Endpoints Actuator endpoints allow you to monitor and interact with your application. Spring Boot includes a number of built-in endpoints and you can also add your own. For example the health endpoint provides basic application health information. The way that endpoints are exposed will depend on the type of technology that you choose. Most applications choose HTTP monitoring, where the ID of the endpoint is mapped to a URL. For example, by default, the health endpoint will be mapped to /health. The following endpoints are available: ID Description Sensitive Default actuator Provides a hypermedia-based “discovery page” for the other endpoints. Requires Spring HATEOAS to be on the classpath. true autoconfig Displays an auto-configuration report showing all auto- configuration candidates and the reason why they ‘were’ or ‘were not’ applied. true beans Displays a complete list of all the Spring beans in your application. true configprops Displays a collated list of all @ConfigurationProperties. true docs Displays documentation, including example requests and responses, for the Actuator’s endpoints. Requires spring- boot-actuator-docs to be on the classpath. false dump Performs a thread dump. true env Exposes properties from Spring’s ConfigurableEnvironment. true flyway Shows any Flyway database migrations that have been applied. true health Shows application health information (when the application is secure, a simple ‘status’ when accessed over an unauthenticated connection or full message details when authenticated). false info Displays arbitrary application info. false liquibase Shows any Liquibase database migrations that have been applied. true logfile Returns the contents of the logfile (if logging.file or logging.path properties have been set). Only available via MVC. Supports the use of the HTTP Range header to retrieve part of the log file’s content. true Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 150 ID Description Sensitive Default metrics Shows ‘metrics’ information for the current application. true mappings Displays a collated list of all @RequestMapping paths. true shutdown Allows the application to be gracefully shutdown (not enabled by default). true trace Displays trace information (by default the last few HTTP requests). true Note Depending on how an endpoint is exposed, the sensitive property may be used as a security hint. For example, sensitive endpoints will require a username/password when they are accessed over HTTP (or simply disabled if web security is not enabled). 47.1 Customizing endpoints Endpoints can be customized using Spring properties. You can change if an endpoint is enabled, if it is considered sensitive and even its id. For example, here is an application.properties that changes the sensitivity and id of the beans endpoint and also enables shutdown. endpoints.beans.id=springbeans endpoints.beans.sensitive=false endpoints.shutdown.enabled=true Note The prefix #endpoints + . + name” is used to uniquely identify the endpoint that is being configured. By default, all endpoints except for shutdown are enabled. If you prefer to specifically “opt-in” endpoint enablement you can use the endpoints.enabled property. For example, the following will disable all endpoints except for info: endpoints.enabled=false endpoints.info.enabled=true Likewise, you can also choose to globally set the “sensitive” flag of all endpoints. By default, the sensitive flag depends on the type of endpoint (see the table above). For example, to mark all endpoints as sensitive except info: endpoints.sensitive=true endpoints.info.sensitive=false 47.2 Hypermedia for actuator MVC endpoints If Spring HATEOAS is on the classpath (e.g. through the spring-boot-starter-hateoas or if you are using Spring Data REST) then the HTTP endpoints from the Actuator are enhanced with Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 151 hypermedia links, and a “discovery page” is added with links to all the endpoints. The “discovery page” is available on /actuator by default. It is implemented as an endpoint, allowing properties to be used to configure its path (endpoints.actuator.path) and whether or not it is enabled (endpoints.actuator.enabled). When a custom management context path is configured, the “discovery page” will automatically move from /actuator to the root of the management context. For example, if the management context path is /management then the discovery page will be available from /management. If the HAL Browser is on the classpath via its webjar (org.webjars:hal-browser), or via the spring-data-rest-hal-browser then an HTML “discovery page”, in the form of the HAL Browser, is also provided. 47.3 CORS support Cross-origin resource sharing (CORS) is a W3C specification that allows you to specify in a flexible way what kind of cross domain requests are authorized. Actuator’s MVC endpoints can be configured to support such scenarios. CORS support is disabled by default and is only enabled once the endpoints.cors.allowed- origins property has been set. The configuration below permits GET and POST calls from the example.com domain: endpoints.cors.allowed-origins=http://example.com endpoints.cors.allowed-methods=GET,POST Tip Check EndpointCorsProperties for a complete list of options. 47.4 Adding custom endpoints If you add a @Bean of type Endpoint then it will automatically be exposed over JMX and HTTP (if there is an server available). An HTTP endpoints can be customized further by creating a bean of type MvcEndpoint. Your MvcEndpoint is not a @Controller but it can use @RequestMapping (and @Managed*) to expose resources. Tip If you are doing this as a library feature consider adding a configuration class annotated with @ManagementContextConfiguration to /META-INF/spring.factories under the key org.springframework.boot.actuate.autoconfigure.ManagementContextConfiguration. If you do that then the endpoint will move to a child context with all the other MVC endpoints if your users ask for a separate management port or address. A configuration declared this way can be a WebConfigurerAdapter if it wants to add static resources (for instance) to the management endpoints. 47.5 Health information Health information can be used to check the status of your running application. It is often used by monitoring software to alert someone if a production system goes down. The default information exposed by the health endpoint depends on how it is accessed. For an unauthenticated connection in a secure Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 152 application a simple ‘status’ message is returned, and for an authenticated connection additional details are also displayed (see Section 48.6, “HTTP health endpoint access restrictions” for HTTP details). Health information is collected from all HealthIndicator beans defined in your ApplicationContext. Spring Boot includes a number of auto-configured HealthIndicators and you can also write your own. 47.6 Security with HealthIndicators Information returned by HealthIndicators is often somewhat sensitive in nature. For example, you probably don’t want to publish details of your database server to the world. For this reason, by default, only the health status is exposed over an unauthenticated HTTP connection. If you are happy for complete health information to always be exposed you can set endpoints.health.sensitive to false. Health responses are also cached to prevent “denial of service” attacks. Use the endpoints.health.time-to-live property if you want to change the default cache period of 1000 milliseconds. Auto-configured HealthIndicators The following HealthIndicators are auto-configured by Spring Boot when appropriate: Name Description CassandraHealthIndicatorChecks that a Cassandra database is up. DiskSpaceHealthIndicatorChecks for low disk space. DataSourceHealthIndicatorChecks that a connection to DataSource can be obtained. ElasticsearchHealthIndicatorChecks that an ElasticSearch cluster is up. JmsHealthIndicatorChecks that a JMS broker is up. MailHealthIndicatorChecks that a mail server is up. MongoHealthIndicatorChecks that a Mongo database is up. RabbitHealthIndicatorChecks that a Rabbit server is up. RedisHealthIndicatorChecks that a Redis server is up. SolrHealthIndicatorChecks that a Solr server is up. Tip It is possible to disable them all using the management.health.defaults.enabled property. Writing custom HealthIndicators To provide custom health information you can register Spring beans that implement the HealthIndicator interface. You need to provide an implementation of the health() method and return a Health response. The Health response should include a status and can optionally include additional details to be displayed. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 153 import org.springframework.boot.actuate.health.HealthIndicator; import org.springframework.stereotype.Component; @Component public class MyHealthIndicator implements HealthIndicator { @Override public Health health() { int errorCode = check(); // perform some specific health check if (errorCode != 0) { return Health.down().withDetail("Error Code", errorCode).build(); } return Health.up().build(); } } Note The identifier for a given HealthIndicator is the name of the bean without the HealthIndicator suffix if it exists. In the example above, the health information will be available in an entry named my. In addition to Spring Boot’s predefined Status types, it is also possible for Health to return a custom Status that represents a new system state. In such cases a custom implementation of the HealthAggregator interface also needs to be provided, or the default implementation has to be configured using the management.health.status.order configuration property. For example, assuming a new Status with code FATAL is being used in one of your HealthIndicator implementations. To configure the severity order add the following to your application properties: management.health.status.order=DOWN, OUT_OF_SERVICE, UNKNOWN, UP You might also want to register custom status mappings with the HealthMvcEndpoint if you access the health endpoint over HTTP. For example you could map FATAL to HttpStatus.SERVICE_UNAVAILABLE. 47.7 Application information Application information exposes various information collected from all InfoContributor beans defined in your ApplicationContext. Spring Boot includes a number of auto-configured InfoContributors and you can also write your own. Auto-configured InfoContributors The following InfoContributors are auto-configured by Spring Boot when appropriate: Name Description EnvironmentInfoContributorExpose any key from the Environment under the info key. GitInfoContributorExpose git information if a git.properties file is available. BuildInfoContributorExpose build information if a META-INF/build-info.properties file is available. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 154 Tip It is possible to disable them all using the management.info.defaults.enabled property. Custom application info information You can customize the data exposed by the info endpoint by setting info.* Spring properties. All Environment properties under the info key will be automatically exposed. For example, you could add the following to your application.properties: info.app.encoding=UTF-8 info.app.java.source=1.8 info.app.java.target=1.8 Tip Rather than hardcoding those values you could also expand info properties at build time. Assuming you are using Maven, you could rewrite the example above as follows: info.app.encoding=@project.build.sourceEncoding@ info.app.java.source=@java.version@ info.app.java.target=@java.version@ Git commit information Another useful feature of the info endpoint is its ability to publish information about the state of your git source code repository when the project was built. If a GitProperties bean is available, the git.branch, git.commit.id and git.commit.time properties will be exposed. Tip A GitProperties bean is auto-configured if a git.properties file is available at the root of the classpath. See Generate git information for more details. If you want to display the full git information (i.e. the full content of git.properties), use the management.info.git.mode property: management.info.git.mode=full Build information The info endpoint can also publish information about your build if a BuildProperties bean is available. This happens if a META-INF/build-info.properties file is available in the classpath. Tip The Maven and Gradle plugins can both generate that file, see Generate build information for more details. Writing custom InfoContributors To provide custom application information you can register Spring beans that implement the InfoContributor interface. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 155 The example below contributes an example entry with a single value: import java.util.Collections; import org.springframework.boot.actuate.info.Info; import org.springframework.boot.actuate.info.InfoContributor; import org.springframework.stereotype.Component; @Component public class ExampleInfoContributor implements InfoContributor { @Override public void contribute(Info.Builder builder) { builder.withDetail("example", Collections.singletonMap("key", "value")); } } If you hit the info endpoint you should see a response that contains the following additional entry: { "example": { "key" : "value" } } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 156 48. Monitoring and management over HTTP If you are developing a Spring MVC application, Spring Boot Actuator will auto-configure all enabled endpoints to be exposed over HTTP. The default convention is to use the id of the endpoint as the URL path. For example, health is exposed as /health. 48.1 Securing sensitive endpoints If you add ‘Spring Security’ to your project, all sensitive endpoints exposed over HTTP will be protected. By default ‘basic’ authentication will be used with the username user and a generated password (which is printed on the console when the application starts). Tip Generated passwords are logged as the application starts. Search for ‘Using default security password’. You can use Spring properties to change the username and password and to change the security role(s) required to access the endpoints. For example, you might set the following in your application.properties: security.user.name=admin security.user.password=secret management.security.roles=SUPERUSER Tip If you don’t use Spring Security and your HTTP endpoints are exposed publicly, you should carefully consider which endpoints you enable. See Section 47.1, “Customizing endpoints” for details of how you can set endpoints.enabled to false then “opt-in” only specific endpoints. 48.2 Customizing the management endpoint paths Sometimes it is useful to group all management endpoints under a single path. For example, your application might already use /info for another purpose. You can use the management.context- path property to set a prefix for your management endpoint: management.context-path=/manage The application.properties example above will change the endpoint from /{id} to /manage/ {id} (e.g. /manage/info). You can also change the “id” of an endpoint (using endpoints.{name}.id) which then changes the default resource path for the MVC endpoint. Legal endpoint ids are composed only of alphanumeric characters (because they can be exposed in a number of places, including JMX object names, where special characters are forbidden). The MVC path can be changed separately by configuring endpoints.{name}.path, and there is no validation on those values (so you can use anything that is legal in a URL path). For example, to change the location of the /health endpoint to /ping/me you can set endpoints.health.path=/ping/me. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 157 Tip If you provide a custom MvcEndpoint remember to include a settable path property, and default it to /{id} if you want your code to behave like the standard MVC endpoints. (Take a look at the HealthMvcEndpoint to see how you might do that.) If your custom endpoint is an Endpoint (not an MvcEndpoint) then Spring Boot will take care of the path for you. 48.3 Customizing the management server port Exposing management endpoints using the default HTTP port is a sensible choice for cloud based deployments. If, however, your application runs inside your own data center you may prefer to expose endpoints using a different HTTP port. The management.port property can be used to change the HTTP port. management.port=8081 Since your management port is often protected by a firewall, and not exposed to the public you might not need security on the management endpoints, even if your main application is secure. In that case you will have Spring Security on the classpath, and you can disable management security like this: management.security.enabled=false (If you don’t have Spring Security on the classpath then there is no need to explicitly disable the management security in this way, and it might even break the application.) 48.4 Customizing the management server address You can customize the address that the management endpoints are available on by setting the management.address property. This can be useful if you want to listen only on an internal or ops- facing network, or to only listen for connections from localhost. Note You can only listen on a different address if the port is different to the main server port. Here is an example application.properties that will not allow remote management connections: management.port=8081 management.address=127.0.0.1 48.5 Disabling HTTP endpoints If you don’t want to expose endpoints over HTTP you can set the management port to -1: management.port=-1 48.6 HTTP health endpoint access restrictions The information exposed by the health endpoint varies depending on whether or not it’s accessed anonymously, and whether or not the enclosing application is secure. By default, when accessed anonymously in a secure application, any details about the server’s health are hidden and the endpoint will simply indicate whether or not the server is up or down. Furthermore, when accessed anonymously, Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 158 the response is cached for a configurable period to prevent the endpoint being used in a denial of service attack. The endpoints.health.time-to-live property is used to configure the caching period in milliseconds. It defaults to 1000, i.e. one second. The above-described restrictions can be enhanced, thereby allowing only authenticated users full access to the health endpoint in a secure application. To do so, set endpoints.health.sensitive to true. Here’s a summary of behavior (with default sensitive flag value “false” indicated in bold): management.security.enabledendpoints.health.sensitiveUnauthenticated Authenticated false false Full content Full content false true Status only Full content true false Status only Full content true true No content Full content Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 159 49. Monitoring and management over JMX Java Management Extensions (JMX) provide a standard mechanism to monitor and manage applications. By default Spring Boot will expose management endpoints as JMX MBeans under the org.springframework.boot domain. 49.1 Customizing MBean names The name of the MBean is usually generated from the id of the endpoint. For example the health endpoint is exposed as org.springframework.boot/Endpoint/healthEndpoint. If your application contains more than one Spring ApplicationContext you may find that names clash. To solve this problem you can set the endpoints.jmx.unique-names property to true so that MBean names are always unique. You can also customize the JMX domain under which endpoints are exposed. Here is an example application.properties: endpoints.jmx.domain=myapp endpoints.jmx.unique-names=true 49.2 Disabling JMX endpoints If you don’t want to expose endpoints over JMX you can set the endpoints.jmx.enabled property to false: endpoints.jmx.enabled=false 49.3 Using Jolokia for JMX over HTTP Jolokia is a JMX-HTTP bridge giving an alternative method of accessing JMX beans. To use Jolokia, simply include a dependency to org.jolokia:jolokia-core. For example, using Maven you would add the following: org.jolokia jolokia-core Jolokia can then be accessed using /jolokia on your management HTTP server. Customizing Jolokia Jolokia has a number of settings that you would traditionally configure using servlet parameters. With Spring Boot you can use your application.properties, simply prefix the parameter with jolokia.config.: jolokia.config.debug=true Disabling Jolokia If you are using Jolokia but you don’t want Spring Boot to configure it, simply set the endpoints.jolokia.enabled property to false: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 160 endpoints.jolokia.enabled=false Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 161 50. Monitoring and management using a remote shell Spring Boot supports an integrated Java shell called ‘CRaSH’. You can use CRaSH to ssh or telnet into your running application. To enable remote shell support, add the following dependency to your project: org.springframework.boot spring-boot-starter-remote-shell Tip If you want to also enable telnet access you will additionally need a dependency on org.crsh:crsh.shell.telnet. Note CRaSH requires to run with a JDK as it compiles commands on the fly. If a basic help command fails, you are probably running with a JRE. 50.1 Connecting to the remote shell By default the remote shell will listen for connections on port 2000. The default user is user and the default password will be randomly generated and displayed in the log output. If your application is using Spring Security, the shell will use the same configuration by default. If not, a simple authentication will be applied and you should see a message like this: Using default password for shell access: ec03e16c-4cf4-49ee-b745-7c8255c1dd7e Linux and OSX users can use ssh to connect to the remote shell, Windows users can download and install PuTTY. $ ssh -p 2000 user@localhost user@localhost's password: . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.4.0.BUILD-SNAPSHOT) on myhost Type help for a list of commands. Spring Boot provides metrics, beans, autoconfig and endpoint commands. Remote shell credentials You can use the management.shell.auth.simple.user.name and management.shell.auth.simple.user.password properties to configure custom connection credentials. It is also possible to use a ‘Spring Security’ AuthenticationManager to handle login duties. See the CrshAutoConfiguration and ShellProperties Javadoc for full details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 162 50.2 Extending the remote shell The remote shell can be extended in a number of interesting ways. Remote shell commands You can write additional shell commands using Groovy or Java (see the CRaSH documentation for details). By default Spring Boot will search for commands in the following locations: • classpath*:/commands/** • classpath*:/crash/commands/** Tip You can change the search path by settings a shell.command-path-patterns property. Here is a simple ‘hello’ command that could be loaded from src/main/resources/commands/ hello.groovy package commands import org.crsh.cli.Command import org.crsh.cli.Usage import org.crsh.command.InvocationContext class hello { @Usage("Say Hello") @Command def main(InvocationContext context) { return "Hello" } } Spring Boot adds some additional attributes to InvocationContext that you can access from your command: Attribute Name Description spring.boot.version The version of Spring Boot spring.version The version of the core Spring Framework spring.beanfactory Access to the Spring BeanFactory spring.environment Access to the Spring Environment Remote shell plugins In addition to new commands, it is also possible to extend other CRaSH shell features. All Spring Beans that extend org.crsh.plugin.CRaSHPlugin will be automatically registered with the shell. For more information please refer to the CRaSH reference documentation. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 163 51. Metrics Spring Boot Actuator includes a metrics service with ‘gauge’ and ‘counter’ support. A ‘gauge’ records a single value; and a ‘counter’ records a delta (an increment or decrement). Spring Boot Actuator also provides a PublicMetrics interface that you can implement to expose metrics that you cannot record via one of those two mechanisms. Look at SystemPublicMetrics for an example. Metrics for all HTTP requests are automatically recorded, so if you hit the metrics endpoint you should see a response similar to this: { "counter.status.200.root": 20, "counter.status.200.metrics": 3, "counter.status.200.star-star": 5, "counter.status.401.root": 4, "gauge.response.star-star": 6, "gauge.response.root": 2, "gauge.response.metrics": 3, "classes": 5808, "classes.loaded": 5808, "classes.unloaded": 0, "heap": 3728384, "heap.committed": 986624, "heap.init": 262144, "heap.used": 52765, "nonheap": 0, "nonheap.committed": 77568, "nonheap.init": 2496, "nonheap.used": 75826, "mem": 986624, "mem.free": 933858, "processors": 8, "threads": 15, "threads.daemon": 11, "threads.peak": 15, "threads.totalStarted": 42, "uptime": 494836, "instance.uptime": 489782, "datasource.primary.active": 5, "datasource.primary.usage": 0.25 } Here we can see basic memory, heap, class loading, processor and thread pool information along with some HTTP metrics. In this instance the root (‘/’) and /metrics URLs have returned HTTP 200 responses 20 and 3 times respectively. It also appears that the root URL returned HTTP 401 (unauthorized) 4 times. The double asterisks (star-star) comes from a request matched by Spring MVC as /** (normally a static resource). The gauge shows the last response time for a request. So the last request to root took 2ms to respond and the last to /metrics took 3ms. Note In this example we are actually accessing the endpoint over HTTP using the /metrics URL, this explains why metrics appears in the response. 51.1 System metrics The following system metrics are exposed by Spring Boot: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 164 • The total system memory in KB (mem) • The amount of free memory in KB (mem.free) • The number of processors (processors) • The system uptime in milliseconds (uptime) • The application context uptime in milliseconds (instance.uptime) • The average system load (systemload.average) • Heap information in KB (heap, heap.committed, heap.init, heap.used) • Thread information (threads, thread.peak, thread.daemon) • Class load information (classes, classes.loaded, classes.unloaded) • Garbage collection information (gc.xxx.count, gc.xxx.time) 51.2 DataSource metrics The following metrics are exposed for each supported DataSource defined in your application: • The number of active connections (datasource.xxx.active) • The current usage of the connection pool (datasource.xxx.usage). All data source metrics share the datasource. prefix. The prefix is further qualified for each data source: • If the data source is the primary data source (that is either the only available data source or the one flagged @Primary amongst the existing ones), the prefix is datasource.primary. • If the data source bean name ends with DataSource, the prefix is the name of the bean without DataSource (i.e. datasource.batch for batchDataSource). • In all other cases, the name of the bean is used. It is possible to override part or all of those defaults by registering a bean with a customized version of DataSourcePublicMetrics. By default, Spring Boot provides metadata for all supported data sources; you can add additional DataSourcePoolMetadataProvider beans if your favorite data source isn’t supported out of the box. See DataSourcePoolMetadataProvidersConfiguration for examples. 51.3 Cache metrics The following metrics are exposed for each supported cache defined in your application: • The current size of the cache (cache.xxx.size) • Hit ratio (cache.xxx.hit.ratio) • Miss ratio (cache.xxx.miss.ratio) Note Cache providers do not expose the hit/miss ratio in a consistent way. While some expose an aggregated value (i.e. the hit ratio since the last time the stats were cleared), others expose a Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 165 temporal value (i.e. the hit ratio of the last second). Check your caching provider documentation for more details. If two different cache managers happen to define the same cache, the name of the cache is prefixed by the name of the CacheManager bean. It is possible to override part or all of those defaults by registering a bean with a customized version of CachePublicMetrics. By default, Spring Boot provides cache statistics for EhCache, Hazelcast, Infinispan, JCache and Guava. You can add additional CacheStatisticsProvider beans if your favorite caching library isn’t supported out of the box. See CacheStatisticsAutoConfiguration for examples. 51.4 Tomcat session metrics If you are using Tomcat as your embedded servlet container, session metrics will automatically be exposed. The httpsessions.active and httpsessions.max keys provide the number of active and maximum sessions. 51.5 Recording your own metrics To record your own metrics inject a CounterService and/or GaugeService into your bean. The CounterService exposes increment, decrement and reset methods; the GaugeService provides a submit method. Here is a simple example that counts the number of times that a method is invoked: import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.actuate.metrics.CounterService; import org.springframework.stereotype.Service; @Service public class MyService { private final CounterService counterService; @Autowired public MyService(CounterService counterService) { this.counterService = counterService; } public void exampleMethod() { this.counterService.increment("services.system.myservice.invoked"); } } Tip You can use any string as a metric name but you should follow guidelines of your chosen store/ graphing technology. Some good guidelines for Graphite are available on Matt Aimonetti’s Blog. 51.6 Adding your own public metrics To add additional metrics that are computed every time the metrics endpoint is invoked, simply register additional PublicMetrics implementation bean(s). By default, all such beans are gathered by the endpoint. You can easily change that by defining your own MetricsEndpoint. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 166 51.7 Special features with Java 8 The default implementation of GaugeService and CounterService provided by Spring Boot depends on the version of Java that you are using. With Java 8 (or better) the implementation switches to a high-performance version optimized for fast writes, backed by atomic in-memory buffers, rather than by the immutable but relatively expensive Metric type (counters are approximately 5 times faster and gauges approximately twice as fast as the repository-based implementations). The Dropwizard metrics services (see below) are also very efficient even for Java 7 (they have backports of some of the Java 8 concurrency libraries), but they do not record timestamps for metric values. If performance of metric gathering is a concern then it is always advisable to use one of the high-performance options, and also to only read metrics infrequently, so that the writes are buffered locally and only read when needed. Note The old MetricRepository and its InMemoryMetricRepository implementation are not used by default if you are on Java 8 or if you are using Dropwizard metrics. 51.8 Metric writers, exporters and aggregation Spring Boot provides a couple of implementations of a marker interface called Exporter which can be used to copy metric readings from the in-memory buffers to a place where they can be analyzed and displayed. Indeed, if you provide a @Bean that implements the MetricWriter interface (or GaugeWriter for simple use cases) and mark it @ExportMetricWriter, then it will automatically be hooked up to an Exporter and fed metric updates every 5 seconds (configured via spring.metrics.export.delay-millis). In addition, any MetricReader that you define and mark as @ExportMetricReader will have its values exported by the default exporter. The default exporter is a MetricCopyExporter which tries to optimize itself by not copying values that haven’t changed since it was last called (the optimization can be switched off using a flag spring.metrics.export.send-latest). Note also that the Dropwizard MetricRegistry has no support for timestamps, so the optimization is not available if you are using Dropwizard metrics (all metrics will be copied on every tick). The default values for the export trigger (delay-millis, includes, excludes and send-latest) can be set as spring.metrics.export.*. Individual values for specific MetricWriters can be set as spring.metrics.export.triggers..* where is a bean name (or pattern for matching bean names). Warning The automatic export of metrics is disabled if you switch off the default MetricRepository (e.g. by using Dropwizard metrics). You can get back the same functionality be declaring a bean of your own of type MetricReader and declaring it to be @ExportMetricReader. Example: Export to Redis If you provide a @Bean of type RedisMetricRepository and mark it @ExportMetricWriter the metrics are exported to a Redis cache for aggregation. The RedisMetricRepository has two important parameters to configure it for this purpose: prefix and key (passed into its constructor). It is best to use a prefix that is unique to the application instance (e.g. using a random value and maybe the logical name of the application to make it possible to correlate with other instances of the Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 167 same application). The “key” is used to keep a global index of all metric names, so it should be unique “globally”, whatever that means for your system (e.g. two instances of the same system could share a Redis cache if they have distinct keys). Example: @Bean @ExportMetricWriter MetricWriter metricWriter(MetricExportProperties export) { return new RedisMetricRepository(connectionFactory, export.getRedis().getPrefix(), export.getRedis().getKey()); } application.properties. spring.metrics.export.redis.prefix: metrics.mysystem.${spring.application.name:application}. ${random.value:0000} spring.metrics.export.redis.key: keys.metrics.mysystem The prefix is constructed with the application name and id at the end, so it can easily be used to identify a group of processes with the same logical name later. Note It’s important to set both the key and the prefix. The key is used for all repository operations, and can be shared by multiple repositories. If multiple repositories share a key (like in the case where you need to aggregate across them), then you normally have a read-only “master” repository that has a short, but identifiable, prefix (like “metrics.mysystem”), and many write-only repositories with prefixes that start with the master prefix (like metrics.mysystem.* in the example above). It is efficient to read all the keys from a “master” repository like that, but inefficient to read a subset with a longer prefix (e.g. using one of the writing repositories). Tip The example above uses MetricExportProperties to inject and extract the key and prefix. This is provided to you as a convenience by Spring Boot, configured with sensible defaults. There is nothing to stop you using your own values as long as they follow the recommendations. Example: Export to Open TSDB If you provide a @Bean of type OpenTsdbGaugeWriter and mark it @ExportMetricWriter metrics are exported to Open TSDB for aggregation. The OpenTsdbGaugeWriter has a url property that you need to set to the Open TSDB “/put” endpoint, e.g. localhost:4242/api/put). It also has a namingStrategy that you can customize or configure to make the metrics match the data structure you need on the server. By default it just passes through the metric name as an Open TSDB metric name, and adds the tags “domain” (with value “org.springframework.metrics”) and “process” (with the value equal to the object hash of the naming strategy). Thus, after running the application and generating some metrics you can inspect the metrics in the TSD UI (localhost:4242 by default). Example: curl localhost:4242/api/query?start=1h-ago&m=max:counter.status.200.root [ { "metric": "counter.status.200.root", "tags": { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 168 "domain": "org.springframework.metrics", "process": "b968a76" }, "aggregateTags": [], "dps": { "1430492872": 2, "1430492875": 6 } } ] Example: Export to Statsd To export metrics to Statsd, make sure first that you have added com.timgroup:java-statsd- client as a dependency of your project (Spring Boot provides a dependency management for it). Then add a spring.metrics.export.statsd.host value to your application.properties file. Connections will be opened to port 8125 unless a spring.metrics.export.statsd.port override is provided. You can use spring.metrics.export.statsd.prefix if you want a custom prefix. Alternatively, you can provide a @Bean of type StatsdMetricWriter and mark it @ExportMetricWriter: @Value("${spring.application.name:application}.${random.value:0000}") private String prefix = "metrics"; @Bean @ExportMetricWriter MetricWriter metricWriter() { return new StatsdMetricWriter(prefix, "localhost", 8125); } Example: Export to JMX If you provide a @Bean of type JmxMetricWriter marked @ExportMetricWriter the metrics are exported as MBeans to the local server (the MBeanExporter is provided by Spring Boot JMX auto- configuration as long as it is switched on). Metrics can then be inspected, graphed, alerted etc. using any tool that understands JMX (e.g. JConsole or JVisualVM). Example: @Bean @ExportMetricWriter MetricWriter metricWriter(MBeanExporter exporter) { return new JmxMetricWriter(exporter); } Each metric is exported as an individual MBean. The format for the ObjectNames is given by an ObjectNamingStrategy which can be injected into the JmxMetricWriter (the default breaks up the metric name and tags the first two period-separated sections in a way that should make the metrics group nicely in JVisualVM or JConsole). 51.9 Aggregating metrics from multiple sources There is an AggregateMetricReader that you can use to consolidate metrics from different physical sources. Sources for the same logical metric just need to publish them with a period-separated prefix, and the reader will aggregate (by truncating the metric names, and dropping the prefix). Counters are summed and everything else (i.e. gauges) take their most recent value. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 169 This is very useful if multiple application instances are feeding to a central (e.g. Redis) repository and you want to display the results. Particularly recommended in conjunction with a MetricReaderPublicMetrics for hooking up to the results to the “/metrics” endpoint. Example: @Autowired private MetricExportProperties export; @Bean public PublicMetrics metricsAggregate() { return new MetricReaderPublicMetrics(aggregatesMetricReader()); } private MetricReader globalMetricsForAggregation() { return new RedisMetricRepository(this.connectionFactory, this.export.getRedis().getAggregatePrefix(), this.export.getRedis().getKey()); } private MetricReader aggregatesMetricReader() { AggregateMetricReader repository = new AggregateMetricReader( globalMetricsForAggregation()); return repository; } Note The example above uses MetricExportProperties to inject and extract the key and prefix. This is provided to you as a convenience by Spring Boot, and the defaults will be sensible. They are set up in MetricExportAutoConfiguration. Note The MetricReaders above are not @Beans and are not marked as @ExportMetricReader because they are just collecting and analyzing data from other repositories, and don’t want to export their values. 51.10 Dropwizard Metrics A default MetricRegistry Spring bean will be created when you declare a dependency to the io.dropwizard.metrics:metrics-core library; you can also register you own @Bean instance if you need customizations. Users of the Dropwizard ‘Metrics’ library will find that Spring Boot metrics are automatically published to com.codahale.metrics.MetricRegistry. Metrics from the MetricRegistry are also automatically exposed via the /metrics endpoint When Dropwizard metrics are in use, the default CounterService and GaugeService are replaced with a DropwizardMetricServices, which is a wrapper around the MetricRegistry (so you can @Autowired one of those services and use it as normal). You can also create “special” Dropwizard metrics by prefixing your metric names with the appropriate type (i.e. timer.*, histogram.* for gauges, and meter.* for counters). 51.11 Message channel integration If a MessageChannel bean called metricsChannel exists, then a MetricWriter will be created that writes metrics to that channel. The writer is automatically hooked up to an exporter (as for all writers), so all metric values will appear on the channel, and additional analysis or actions can be taken by subscribers (it’s up to you to provide the channel and any subscribers you need). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 170 52. Auditing Spring Boot Actuator has a flexible audit framework that will publish events once Spring Security is in play (‘authentication success’, ‘failure’ and ‘access denied’ exceptions by default). This can be very useful for reporting, and also to implement a lock-out policy based on authentication failures. To customize published security events you can provide your own implementations of AbstractAuthenticationAuditListener and AbstractAuthorizationAuditListener. You can also choose to use the audit services for your own business events. To do that you can either inject the existing AuditEventRepository into your own components and use that directly, or you can simply publish AuditApplicationEvent via the Spring ApplicationEventPublisher (using ApplicationEventPublisherAware). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 171 53. Tracing Tracing is automatically enabled for all HTTP requests. You can view the trace endpoint and obtain basic information about the last few requests: [{ "timestamp": 1394343677415, "info": { "method": "GET", "path": "/trace", "headers": { "request": { "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8", "Connection": "keep-alive", "Accept-Encoding": "gzip, deflate", "User-Agent": "Mozilla/5.0 Gecko/Firefox", "Accept-Language": "en-US,en;q=0.5", "Cookie": "_ga=GA1.1.827067509.1390890128; ..." "Authorization": "Basic ...", "Host": "localhost:8080" }, "response": { "Strict-Transport-Security": "max-age=31536000 ; includeSubDomains", "X-Application-Context": "application:8080", "Content-Type": "application/json;charset=UTF-8", "status": "200" } } } },{ "timestamp": 1394343684465, ... }] 53.1 Custom tracing If you need to trace additional events you can inject a TraceRepository into your Spring beans. The add method accepts a single Map structure that will be converted to JSON and logged. By default an InMemoryTraceRepository will be used that stores the last 100 events. You can define your own instance of the InMemoryTraceRepository bean if you need to expand the capacity. You can also create your own alternative TraceRepository implementation if needed. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 172 54. Process monitoring In Spring Boot Actuator you can find a couple of classes to create files that are useful for process monitoring: • ApplicationPidFileWriter creates a file containing the application PID (by default in the application directory with the file name application.pid). • EmbeddedServerPortFileWriter creates a file (or files) containing the ports of the embedded server (by default in the application directory with the file name application.port). These writers are not activated by default, but you can enable them in one of the ways described below. 54.1 Extend configuration In META-INF/spring.factories file you can activate the listener(s) that writes a PID file. Example: org.springframework.context.ApplicationListener=\ org.springframework.boot.actuate.system.ApplicationPidFileWriter, org.springframework.boot.actuate.system.EmbeddedServerPortFileWriter 54.2 Programmatically You can also activate a listener by invoking the SpringApplication.addListeners(…) method and passing the appropriate Writer object. This method also allows you to customize the file name and path via the Writer constructor. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 173 55. What to read next If you want to explore some of the concepts discussed in this chapter, you can take a look at the actuator sample applications. You also might want to read about graphing tools such as Graphite. Otherwise, you can continue on, to read about ‘deployment options’ or jump ahead for some in-depth information about Spring Boot’s build tool plugins. Part VI. Deploying Spring Boot applications Spring Boot’s flexible packaging options provide a great deal of choice when it comes to deploying your application. You can easily deploy Spring Boot applications to a variety of cloud platforms, to a container images (such as Docker) or to virtual/real machines. This section covers some of the more common deployment scenarios. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 175 56. Deploying to the cloud Spring Boot’s executable jars are ready-made for most popular cloud PaaS (platform-as-a-service) providers. These providers tend to require that you “bring your own container”; they manage application processes (not Java applications specifically), so they need some intermediary layer that adapts your application to the cloud’s notion of a running process. Two popular cloud providers, Heroku and Cloud Foundry, employ a “buildpack” approach. The buildpack wraps your deployed code in whatever is needed to start your application: it might be a JDK and a call to java, it might be an embedded web server, or it might be a full-fledged application server. A buildpack is pluggable, but ideally you should be able to get by with as few customizations to it as possible. This reduces the footprint of functionality that is not under your control. It minimizes divergence between development and production environments. Ideally, your application, like a Spring Boot executable jar, has everything that it needs to run packaged within it. In this section we’ll look at what it takes to get the simple application that we developed in the “Getting Started” section up and running in the Cloud. 56.1 Cloud Foundry Cloud Foundry provides default buildpacks that come into play if no other buildpack is specified. The Cloud Foundry Java buildpack has excellent support for Spring applications, including Spring Boot. You can deploy stand-alone executable jar applications, as well as traditional .war packaged applications. Once you’ve built your application (using, for example, mvn clean package) and installed the cf command line tool, simply deploy your application using the cf push command as follows, substituting the path to your compiled .jar. Be sure to have logged in with your cf command line client before pushing an application. $ cf push acloudyspringtime -p target/demo-0.0.1-SNAPSHOT.jar See the cf push documentation for more options. If there is a Cloud Foundry manifest.yml file present in the same directory, it will be consulted. Note Here we are substituting acloudyspringtime for whatever value you give cf as the name of your application. At this point cf will start uploading your application: Uploading acloudyspringtime... OK Preparing to start acloudyspringtime... OK -----> Downloaded app package (8.9M) -----> Java Buildpack source: system -----> Downloading Open JDK 1.7.0_51 from .../x86_64/openjdk-1.7.0_51.tar.gz (1.8s) Expanding Open JDK to .java-buildpack/open_jdk (1.2s) -----> Downloading Spring Auto Reconfiguration from 0.8.7 .../auto-reconfiguration-0.8.7.jar (0.1s) -----> Uploading droplet (44M) Checking status of app 'acloudyspringtime'... 0 of 1 instances running (1 starting) ... 0 of 1 instances running (1 down) ... 0 of 1 instances running (1 starting) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 176 ... 1 of 1 instances running (1 running) App started Congratulations! The application is now live! It’s easy to then verify the status of the deployed application: $ cf apps Getting applications in ... OK name requested state instances memory disk urls ... acloudyspringtime started 1/1 512M 1G acloudyspringtime.cfapps.io ... Once Cloud Foundry acknowledges that your application has been deployed, you should be able to hit the application at the URI given, in this case http://acloudyspringtime.cfapps.io/. Binding to services By default, metadata about the running application as well as service connection information is exposed to the application as environment variables (for example: $VCAP_SERVICES). This architecture decision is due to Cloud Foundry’s polyglot (any language and platform can be supported as a buildpack) nature; process-scoped environment variables are language agnostic. Environment variables don’t always make for the easiest API so Spring Boot automatically extracts them and flattens the data into properties that can be accessed through Spring’s Environment abstraction: @Component class MyBean implements EnvironmentAware { private String instanceId; @Override public void setEnvironment(Environment environment) { this.instanceId = environment.getProperty("vcap.application.instance_id"); } // ... } All Cloud Foundry properties are prefixed with vcap. You can use vcap properties to access application information (such as the public URL of the application) and service information (such as database credentials). See CloudFoundryVcapEnvironmentPostProcessor Javadoc for complete details. Tip The Spring Cloud Connectors project is a better fit for tasks such as configuring a DataSource. Spring Boot includes auto-configuration support and a spring-boot-starter-cloud- connectors starter. 56.2 Heroku Heroku is another popular PaaS platform. To customize Heroku builds, you provide a Procfile, which provides the incantation required to deploy an application. Heroku assigns a port for the Java application to use and then ensures that routing to the external URI works. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 177 You must configure your application to listen on the correct port. Here’s the Procfile for our starter REST application: web: java -Dserver.port=$PORT -jar target/demo-0.0.1-SNAPSHOT.jar Spring Boot makes -D arguments available as properties accessible from a Spring Environment instance. The server.port configuration property is fed to the embedded Tomcat, Jetty or Undertow instance which then uses it when it starts up. The $PORT environment variable is assigned to us by the Heroku PaaS. Heroku by default will use Java 1.8. This is fine as long as your Maven or Gradle build is set to use the same version (Maven users can use the java.version property). If you want to use JDK 1.7, create a new file adjacent to your pom.xml and Procfile, called system.properties. In this file add the following: java.runtime.version=1.7 This should be everything you need. The most common workflow for Heroku deployments is to git push the code to production. $ git push heroku master Initializing repository, done. Counting objects: 95, done. Delta compression using up to 8 threads. Compressing objects: 100% (78/78), done. Writing objects: 100% (95/95), 8.66 MiB | 606.00 KiB/s, done. Total 95 (delta 31), reused 0 (delta 0) -----> Java app detected -----> Installing OpenJDK 1.8... done -----> Installing Maven 3.3.1... done -----> Installing settings.xml... done -----> Executing: mvn -B -DskipTests=true clean install [INFO] Scanning for projects... Downloading: http://repo.spring.io/... Downloaded: http://repo.spring.io/... (818 B at 1.8 KB/sec) .... Downloaded: http://s3pository.heroku.com/jvm/... (152 KB at 595.3 KB/sec) [INFO] Installing /tmp/build_0c35a5d2-a067-4abc-a232-14b1fb7a8229/target/... [INFO] Installing /tmp/build_0c35a5d2-a067-4abc-a232-14b1fb7a8229/pom.xml ... [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 59.358s [INFO] Finished at: Fri Mar 07 07:28:25 UTC 2014 [INFO] Final Memory: 20M/493M [INFO] ------------------------------------------------------------------------ -----> Discovering process types Procfile declares types -> web -----> Compressing... done, 70.4MB -----> Launching... done, v6 http://agile-sierra-1405.herokuapp.com/ deployed to Heroku To git@heroku.com:agile-sierra-1405.git * [new branch] master -> master Your application should now be up and running on Heroku. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 178 56.3 OpenShift OpenShift is the RedHat public (and enterprise) PaaS solution. Like Heroku, it works by running scripts triggered by git commits, so you can script the launching of a Spring Boot application in pretty much any way you like as long as the Java runtime is available (which is a standard feature you can ask for at OpenShift). To do this you can use the DIY Cartridge and hooks in your repository under .openshift/ action_scripts: The basic model is to: 1. Ensure Java and your build tool are installed remotely, e.g. using a pre_build hook (Java and Maven are installed by default, Gradle is not) 2. Use a build hook to build your jar (using Maven or Gradle), e.g. #!/bin/bash cd $OPENSHIFT_REPO_DIR mvn package -s .openshift/settings.xml -DskipTests=true 3. Add a start hook that calls java -jar … #!/bin/bash cd $OPENSHIFT_REPO_DIR nohup java -jar target/*.jar --server.port=${OPENSHIFT_DIY_PORT} --server.address=${OPENSHIFT_DIY_IP} & 4. Use a stop hook (since the start is supposed to return cleanly), e.g. #!/bin/bash source $OPENSHIFT_CARTRIDGE_SDK_BASH PID=$(ps -ef | grep java.*\.jar | grep -v grep | awk '{ print $2 }') if [ -z "$PID" ] then client_result "Application is already stopped" else kill $PID fi 5. Embed service bindings from environment variables provided by the platform in your application.properties, e.g. spring.datasource.url: jdbc:mysql://${OPENSHIFT_MYSQL_DB_HOST}:${OPENSHIFT_MYSQL_DB_PORT}/ ${OPENSHIFT_APP_NAME} spring.datasource.username: ${OPENSHIFT_MYSQL_DB_USERNAME} spring.datasource.password: ${OPENSHIFT_MYSQL_DB_PASSWORD} There’s a blog on running Gradle in OpenShift on their website that will get you started with a gradle build to run the app. 56.4 Boxfuse and Amazon Web Services Boxfuse works by turning your Spring Boot executable jar or war into a minimal VM image that can be deployed unchanged either on VirtualBox or on AWS. Boxfuse comes with deep integration for Spring Boot and will use the information from your Spring Boot configuration file to automatically configure ports and health check URLs. Boxfuse leverages this information both for the images it produces as well as for all the resources it provisions (instances, security groups, elastic load balancers, etc). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 179 Once you have created a Boxfuse account, connected it to your AWS account, and installed the latest version of the Boxfuse Client, you can deploy your Spring Boot application to AWS as follows (ensure the application has been built by Maven or Gradle first using, for example, mvn clean package): $ boxfuse run myapp-1.0.jar -env=prod See the boxfuse run documentation for more options. If there is a boxfuse.com/docs/commandline/ #configuration [boxfuse.conf] file present in the current directory, it will be consulted. Tip By default Boxfuse will activate a Spring profile named boxfuse on startup and if your executable jar or war contains an boxfuse.com/docs/payloads/springboot.html#configuration [application-boxfuse.properties] file, Boxfuse will base its configuration based on the properties it contains. At this point boxfuse will create an image for your application, upload it, and then configure and start the necessary resources on AWS: Fusing Image for myapp-1.0.jar ... Image fused in 00:06.838s (53937 K) -> axelfontaine/myapp:1.0 Creating axelfontaine/myapp ... Pushing axelfontaine/myapp:1.0 ... Verifying axelfontaine/myapp:1.0 ... Creating Elastic IP ... Mapping myapp-axelfontaine.boxfuse.io to 52.28.233.167 ... Waiting for AWS to create an AMI for axelfontaine/myapp:1.0 in eu-central-1 (this may take up to 50 seconds) ... AMI created in 00:23.557s -> ami-d23f38cf Creating security group boxfuse-sg_axelfontaine/myapp:1.0 ... Launching t2.micro instance of axelfontaine/myapp:1.0 (ami-d23f38cf) in eu-central-1 ... Instance launched in 00:30.306s -> i-92ef9f53 Waiting for AWS to boot Instance i-92ef9f53 and Payload to start at http://52.28.235.61/ ... Payload started in 00:29.266s -> http://52.28.235.61/ Remapping Elastic IP 52.28.233.167 to i-92ef9f53 ... Waiting 15s for AWS to complete Elastic IP Zero Downtime transition ... Deployment completed successfully. axelfontaine/myapp:1.0 is up and running at http://myapp- axelfontaine.boxfuse.io/ Your application should now be up and running on AWS. There’s a blog on deploying Spring Boot apps on EC2 as well as documentation for the Boxfuse Spring Boot integration on their website that will get you started with a Maven build to run the app. 56.5 Google App Engine Google App Engine is tied to the Servlet 2.5 API, so you can’t deploy a Spring Application there without some modifications. See the Servlet 2.5 section of this guide. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 180 57. Installing Spring Boot applications In additional to running Spring Boot applications using java -jar it is also possible to make fully executable applications for Unix systems. This makes it very easy to install and manage Spring Boot applications in common production environments. To create a ‘fully executable’ jar with Maven use the following plugin configuration: org.springframework.boot spring-boot-maven-plugin true With Gradle, the equivalent configuration would be: apply plugin: 'spring-boot' springBoot { executable = true } Note Fully executable jars work by embedding an extra script at the front of the file. Not all tools currently accept this format so you may not always be able to use this technique. Note The default script supports most Linux distributions and is tested on CentOS and Ubuntu. Other platforms, such as OS X and FreeBSD, will require the use of a custom embeddedLaunchScript. Note When a fully executable jar is run, it uses the jar’s directory as the working directory. 57.1 Unix/Linux services Spring Boot application can be easily started as Unix/Linux services using either init.d or systemd. Installation as an init.d service (System V) The default executable script that can be embedded into Spring Boot jars will act as an init.d script when it is symlinked to /etc/init.d. The standard start, stop, restart and status commands can be used. The script supports the following features: • Starts the services as the user that owns the jar file • Tracks application’s PID using /var/run//.pid • Writes console logs to /var/log/.log Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 181 Assuming that you have a Spring Boot application installed in /var/myapp, to install a Spring Boot application as an init.d service simply create a symlink: $ sudo ln -s /var/myapp/myapp.jar /etc/init.d/myapp Once installed, you can start and stop the service in the usual way. You can also flag the application to start automatically using your standard operating system tools. For example, if you use Debian: $ update-rc.d myapp defaults Securing an init.d service Note The following is a set of guidelines on how to secure a Spring Boot application that’s being run as an init.d service. It is not intended to be an exhaustive list of everything that should be done to harden an application and the environment in which it runs. When executed as root, as is the case when root is being used to start an init.d service, the default executable script will run the application as the user which owns the jar file. You should never run a Spring Boot application as root so your application’s jar file should never be owned by root. Instead, create a specific user to run your application and use chown to make it the owner of the jar file. For example: $ chown bootapp:bootapp your-app.jar In this case, the default executable script will run the application as the bootapp user. Tip To reduce the chances of the application’s user account being compromised, you should consider preventing it from using a login shell. Set the account’s shell to /usr/sbin/nologin, for example. You should also take steps to prevent the modification of your application’s jar file. Firstly, configure its permissions so that it cannot be written and can only be read or executed by its owner: $ chmod 500 your-app.jar Secondly, you should also take steps to limit the damage if your application or the account that’s running it is compromised. If an attacker does gain access, they could make the jar file writable and change its contents. One way to protect against this is to make it immutable using chattr: $ sudo chattr +i your-app.jar This will prevent any user, including root, from modifying the jar. If root is used to control the application’s service and you use a .conf file to customize its startup, the .conf file will be read and evaluated by the root user. It should be secured accordingly. Use chmod so that the file can only be read by the owner and use chown to make root the owner: $ chmod 400 your-app.conf $ sudo chown root:root your-app.conf Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 182 Installation as a systemd service Systemd is the successor of the System V init system, and is now being used by many modern Linux distributions. Although you can continue to use init.d scripts with systemd, it is also possible to launch Spring Boot applications using systemd ‘service’ scripts. Assuming that you have a Spring Boot application installed in /var/myapp, to install a Spring Boot application as a systemd service create a script named myapp.service using the following example and place it in /etc/systemd/system directory: [Unit] Description=myapp After=syslog.target [Service] User=myapp ExecStart=/var/myapp/myapp.jar SuccessExitStatus=143 [Install] WantedBy=multi-user.target Tip Remember to change the Description, User and ExecStart fields for your application. Note that unlike when running as an init.d service, user that runs the application, PID file and console log file behave differently under systemd and must be configured using appropriate fields in ‘service’ script. Consult the service unit configuration man page for more details. To flag the application to start automatically on system boot use the following command: $ systemctl enable myapp.service Refer to man systemctl for more details. Customizing the startup script The script accepts the following parameters as environment variables, so you can change the default behavior in a script or on the command line: Variable Description MODE The “mode” of operation. The default depends on the way the jar was built, but will usually be auto (meaning it tries to guess if it is an init script by checking if it is a symlink in a directory called init.d). You can explicitly set it to service so that the stop|start|status|restart commands work, or to run if you just want to run the script in the foreground. USE_START_STOP_DAEMONIf the start-stop-daemon command, when it’s available, should be used to control the process. Defaults to true. PID_FOLDER The root name of the pid folder (/var/run by default). LOG_FOLDER The name of the folder to put log files in (/var/log by default). CONF_FOLDERThe name of the folder to read .conf files from (same folder as jar-file by default). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 183 Variable Description LOG_FILENAMEThe name of the log file in the LOG_FOLDER (.log by default). APP_NAME The name of the app. If the jar is run from a symlink the script guesses the app name, but if it is not a symlink, or you want to explicitly set the app name this can be useful. RUN_ARGS The arguments to pass to the program (the Spring Boot app). JAVA_HOME The location of the java executable is discovered by using the PATH by default, but you can set it explicitly if there is an executable file at $JAVA_HOME/bin/java. JAVA_OPTS Options that are passed to the JVM when it is launched. JARFILE The explicit location of the jar file, in case the script is being used to launch a jar that it is not actually embedded in. DEBUG if not empty will set the -x flag on the shell process, making it easy to see the logic in the script. Note The PID_FOLDER, LOG_FOLDER and LOG_FILENAME variables are only valid for an init.d service. With systemd the equivalent customizations are made using ‘service’ script. Check the service unit configuration man page for more details. In addition, the following properties can be changed when the script is written by using the embeddedLaunchScriptProperties option of the Spring Boot Maven or Gradle plugins. Name Description mode The script mode. Defaults to auto. initInfoProvidesThe Provides section of “INIT INFO”. Defaults to spring-boot-application for Gradle and to ${project.artifactId} for Maven. initInfoShortDescriptionThe Short-Description section of “INIT INFO”. Defaults to Spring Boot Application for Gradle and to ${project.name} for Maven. initInfoDescriptionThe Description section of “INIT INFO”. Defaults to Spring Boot Application for Gradle and to ${project.description} (falling back to ${project.name}) for Maven. initInfoChkconfigThe chkconfig section of “INIT INFO”. Defaults to 2345 99 01. logFolder The default value for LOG_FOLDER. Only valid for an init.d service. pidFolder The default value for PID_FOLDER. Only valid for an init.d service. useStartStopDaemonIf the start-stop-daemon command, when it’s available, should be used to control the process. Defaults to true. Customizing the startup script with a conf file With the exception of JARFILE and APP_NAME, the above settings can be configured using a .conf file, Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 184 JAVA_OPTS=-Xmx1024M LOG_FOLDER=/custom/log/folder The file is expected next to the jar file and have the same name but suffixed with .conf rather than .jar. For example, a jar named /var/myapp/myapp.jar will use the configuration file named / var/myapp/myapp.conf if it exists. You can also use the CONF_FOLDER property to customize the location of that file. To learn about securing this file appropriately, please refer to the guidelines for securing an init.d service. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 185 58. Microsoft Windows services Spring Boot application can be started as Windows service using winsw. A sample maintained separately to the core of Spring Boot describes step-by-step how you can create a Windows service for your Spring Boot application. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 186 59. What to read next Check out the Cloud Foundry, Heroku, OpenShift and Boxfuse web sites for more information about the kinds of features that a PaaS can offer. These are just four of the most popular Java PaaS providers, since Spring Boot is so amenable to cloud-based deployment you’re free to consider other providers as well. The next section goes on to cover the Spring Boot CLI; or you can jump ahead to read about build tool plugins. Part VII. Spring Boot CLI The Spring Boot CLI is a command line tool that can be used if you want to quickly develop with Spring. It allows you to run Groovy scripts, which means that you have a familiar Java-like syntax, without so much boilerplate code. You can also bootstrap a new project or write your own command for it. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 188 60. Installing the CLI The Spring Boot CLI can be installed manually; using SDKMAN! (the SDK Manager) or using Homebrew or MacPorts if you are an OSX user. See Section 10.2, “Installing the Spring Boot CLI” in the “Getting started” section for comprehensive installation instructions. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 189 61. Using the CLI Once you have installed the CLI you can run it by typing spring. If you run spring without any arguments, a simple help screen is displayed: $ spring usage: spring [--help] [--version] [] Available commands are: run [options] [--] [args] Run a spring groovy script ... more command help is shown here You can use help to get more details about any of the supported commands. For example: $ spring help run spring run - Run a spring groovy script usage: spring run [options] [--] [args] Option Description ------ ----------- --autoconfigure [Boolean] Add autoconfigure compiler transformations (default: true) --classpath, -cp Additional classpath entries -e, --edit Open the file with the default system editor --no-guess-dependencies Do not attempt to guess dependencies --no-guess-imports Do not attempt to guess imports -q, --quiet Quiet logging -v, --verbose Verbose logging of dependency resolution --watch Watch the specified file for changes The version command provides a quick way to check which version of Spring Boot you are using. $ spring version Spring CLI v1.4.0.BUILD-SNAPSHOT 61.1 Running applications using the CLI You can compile and run Groovy source code using the run command. The Spring Boot CLI is completely self-contained so you don’t need any external Groovy installation. Here is an example “hello world” web application written in Groovy: hello.groovy. @RestController class WebApplication { @RequestMapping("/") String home() { "Hello World!" } } To compile and run the application type: $ spring run hello.groovy Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 190 To pass command line arguments to the application, you need to use a -- to separate them from the “spring” command arguments, e.g. $ spring run hello.groovy -- --server.port=9000 To set JVM command line arguments you can use the JAVA_OPTS environment variable, e.g. $ JAVA_OPTS=-Xmx1024m spring run hello.groovy Deduced “grab” dependencies Standard Groovy includes a @Grab annotation which allows you to declare dependencies on a third- party libraries. This useful technique allows Groovy to download jars in the same way as Maven or Gradle would, but without requiring you to use a build tool. Spring Boot extends this technique further, and will attempt to deduce which libraries to “grab” based on your code. For example, since the WebApplication code above uses @RestController annotations, “Tomcat” and “Spring MVC” will be grabbed. The following items are used as “grab hints”: Items Grabs JdbcTemplate, NamedParameterJdbcTemplate, DataSource JDBC Application. @EnableJms JMS Application. @EnableCaching Caching abstraction. @Test JUnit. @EnableRabbit RabbitMQ. @EnableReactor Project Reactor. extends Specification Spock test. @EnableBatchProcessing Spring Batch. @MessageEndpoint @EnableIntegrationPatterns Spring Integration. @EnableDeviceResolver Spring Mobile. @Controller @RestController @EnableWebMvc Spring MVC + Embedded Tomcat. @EnableWebSecurity Spring Security. @EnableTransactionManagement Spring Transaction Management. Tip See subclasses of CompilerAutoConfiguration in the Spring Boot CLI source code to understand exactly how customizations are applied. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 191 Deduced “grab” coordinates Spring Boot extends Groovy’s standard @Grab support by allowing you to specify a dependency without a group or version, for example @Grab('freemarker'). This will consult Spring Boot’s default dependency metadata to deduce the artifact’s group and version. Note that the default metadata is tied to the version of the CLI that you’re using – it will only change when you move to a new version of the CLI, putting you in control of when the versions of your dependencies may change. A table showing the dependencies and their versions that are included in the default metadata can be found in the appendix. Default import statements To help reduce the size of your Groovy code, several import statements are automatically included. Notice how the example above refers to @Component, @RestController and @RequestMapping without needing to use fully-qualified names or import statements. Tip Many Spring annotations will work without using import statements. Try running your application to see what fails before adding imports. Automatic main method Unlike the equivalent Java application, you do not need to include a public static void main(String[] args) method with your Groovy scripts. A SpringApplication is automatically created, with your compiled code acting as the source. Custom dependency management By default, the CLI uses the dependency management declared in spring-boot-dependencies when resolving @Grab dependencies. Additional dependency management, that will override the default dependency management, can be configured using the @DependencyManagementBom annotation. The annotation’s value should specify the coordinates (groupId:artifactId:version) of one or more Maven BOMs. For example, the following declaration: @DependencyManagementBom("com.example.custom-bom:1.0.0") Will pick up custom-bom-1.0.0.pom in a Maven repository under com/example/custom- versions/1.0.0/. When multiple BOMs are specified they are applied in the order that they’re declared. For example: @DependencyManagementBom(["com.example.custom-bom:1.0.0", "com.example.another-bom:1.0.0"]) indicates that dependency management in another-bom will override the dependency management in custom-bom. You can use @DependencyManagementBom anywhere that you can use @Grab, however, to ensure consistent ordering of the dependency management, you can only use @DependencyManagementBom at most once in your application. A useful source of dependency management (that is Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 192 a superset of Spring Boot’s dependency management) is the Spring IO Platform, e.g. @DependencyManagementBom('io.spring.platform:platform-bom:1.1.2.RELEASE'). 61.2 Testing your code The test command allows you to compile and run tests for your application. Typical usage looks like this: $ spring test app.groovy tests.groovy Total: 1, Success: 1, : Failures: 0 Passed? true In this example, tests.groovy contains JUnit @Test methods or Spock Specification classes. All the common framework annotations and static methods should be available to you without having to import them. Here is the tests.groovy file that we used above (with a JUnit test): class ApplicationTests { @Test void homeSaysHello() { assertEquals("Hello World!", new WebApplication().home()) } } Tip If you have more than one test source files, you might prefer to organize them into a test directory. 61.3 Applications with multiple source files You can use “shell globbing” with all commands that accept file input. This allows you to easily use multiple files from a single directory, e.g. $ spring run *.groovy This technique can also be useful if you want to segregate your “test” or “spec” code from the main application code: $ spring test app/*.groovy test/*.groovy 61.4 Packaging your application You can use the jar command to package your application into a self-contained executable jar file. For example: $ spring jar my-app.jar *.groovy The resulting jar will contain the classes produced by compiling the application and all of the application’s dependencies so that it can then be run using java -jar. The jar file will also contain entries from the application’s classpath. You can add explicit paths to the jar using --include and --exclude (both are comma-separated, and both accept prefixes to the values “+” and “-” to signify that they should be removed from the defaults). The default includes are Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 193 public/**, resources/**, static/**, templates/**, META-INF/**, * and the default excludes are .*, repository/**, build/**, target/**, **/*.jar, **/*.groovy See the output of spring help jar for more information. 61.5 Initialize a new project The init command allows you to create a new project using start.spring.io without leaving the shell. For example: $ spring init --dependencies=web,data-jpa my-project Using service at https://start.spring.io Project extracted to '/Users/developer/example/my-project' This creates a my-project directory with a Maven-based project using spring-boot-starter- web and spring-boot-starter-data-jpa. You can list the capabilities of the service using the -- list flag $ spring init --list ======================================= Capabilities of https://start.spring.io ======================================= Available dependencies: ----------------------- actuator - Actuator: Production ready features to help you monitor and manage your application ... web - Web: Support for full-stack web development, including Tomcat and spring-webmvc websocket - Websocket: Support for WebSocket development ws - WS: Support for Spring Web Services Available project types: ------------------------ gradle-build - Gradle Config [format:build, build:gradle] gradle-project - Gradle Project [format:project, build:gradle] maven-build - Maven POM [format:build, build:maven] maven-project - Maven Project [format:project, build:maven] (default) ... The init command supports many options, check the help output for more details. For instance, the following command creates a gradle project using Java 8 and war packaging: $ spring init --build=gradle --java-version=1.8 --dependencies=websocket --packaging=war sample-app.zip Using service at https://start.spring.io Content saved to 'sample-app.zip' 61.6 Using the embedded shell Spring Boot includes command-line completion scripts for BASH and zsh shells. If you don’t use either of these shells (perhaps you are a Windows user) then you can use the shell command to launch an integrated shell. $ spring shell Spring Boot (v1.4.0.BUILD-SNAPSHOT) Hit TAB to complete. Type \'help' and hit RETURN for help, and \'exit' to quit. From inside the embedded shell you can run other commands directly: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 194 $ version Spring CLI v1.4.0.BUILD-SNAPSHOT The embedded shell supports ANSI color output as well as tab completion. If you need to run a native command you can use the ! prefix. Hitting ctrl-c will exit the embedded shell. 61.7 Adding extensions to the CLI You can add extensions to the CLI using the install command. The command takes one or more sets of artifact coordinates in the format group:artifact:version. For example: $ spring install com.example:spring-boot-cli-extension:1.0.0.RELEASE In addition to installing the artifacts identified by the coordinates you supply, all of the artifacts' dependencies will also be installed. To uninstall a dependency use the uninstall command. As with the install command, it takes one or more sets of artifact coordinates in the format group:artifact:version. For example: $ spring uninstall com.example:spring-boot-cli-extension:1.0.0.RELEASE It will uninstall the artifacts identified by the coordinates you supply and their dependencies. To uninstall all additional dependencies you can use the --all option. For example: $ spring uninstall --all Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 195 62. Developing application with the Groovy beans DSL Spring Framework 4.0 has native support for a beans{} “DSL” (borrowed from Grails), and you can embed bean definitions in your Groovy application scripts using the same format. This is sometimes a good way to include external features like middleware declarations. For example: @Configuration class Application implements CommandLineRunner { @Autowired SharedService service @Override void run(String... args) { println service.message } } import my.company.SharedService beans { service(SharedService) { message = "Hello World" } } You can mix class declarations with beans{} in the same file as long as they stay at the top level, or you can put the beans DSL in a separate file if you prefer. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 196 63. Configuring the CLI with settings.xml The Spring Boot CLI uses Aether, Maven’s dependency resolution engine, to resolve dependencies. The CLI makes use of the Maven configuration found in ~/.m2/settings.xml to configure Aether. The following configuration settings are honored by the CLI: • Offline • Mirrors • Servers • Proxies • Profiles • Activation • Repositories • Active profiles Please refer to Maven’s settings documentation for further information. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 197 64. What to read next There are some sample groovy scripts available from the GitHub repository that you can use to try out the Spring Boot CLI. There is also extensive Javadoc throughout the source code. If you find that you reach the limit of the CLI tool, you will probably want to look at converting your application to full Gradle or Maven built “groovy project”. The next section covers Spring Boot’s Build tool plugins that you can use with Gradle or Maven. Part VIII. Build tool plugins Spring Boot provides build tool plugins for Maven and Gradle. The plugins offer a variety of features, including the packaging of executable jars. This section provides more details on both plugins, as well as some help should you need to extend an unsupported build system. If you are just getting started, you might want to read “Chapter 13, Build systems” from the Part III, “Using Spring Boot” section first. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 199 65. Spring Boot Maven plugin The Spring Boot Maven Plugin provides Spring Boot support in Maven, allowing you to package executable jar or war archives and run an application “in-place”. To use it you must be using Maven 3.2 (or better). Note Refer to the Spring Boot Maven Plugin Site for complete plugin documentation. 65.1 Including the plugin To use the Spring Boot Maven Plugin simply include the appropriate XML in the plugins section of your pom.xml 4.0.0 org.springframework.boot spring-boot-maven-plugin 1.4.0.BUILD-SNAPSHOT repackage This configuration will repackage a jar or war that is built during the package phase of the Maven lifecycle. The following example shows both the repackaged jar, as well as the original jar, in the target directory: $ mvn package $ ls target/*.jar target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original If you don’t include the configuration as above, you can run the plugin on its own (but only if the package goal is used as well). For example: $ mvn package spring-boot:repackage $ ls target/*.jar target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original If you are using a milestone or snapshot release you will also need to add appropriate pluginRepository elements: spring-snapshots http://repo.spring.io/snapshot Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 200 spring-milestones http://repo.spring.io/milestone 65.2 Packaging executable jar and war files Once spring-boot-maven-plugin has been included in your pom.xml it will automatically attempt to rewrite archives to make them executable using the spring-boot:repackage goal. You should configure your project to build a jar or war (as appropriate) using the usual packaging element: jar Your existing archive will be enhanced by Spring Boot during the package phase. The main class that you want to launch can either be specified using a configuration option, or by adding a Main-Class attribute to the manifest in the usual way. If you don’t specify a main class the plugin will search for a class with a public static void main(String[] args) method. To build and run a project artifact, you can type the following: $ mvn package $ java -jar target/mymodule-0.0.1-SNAPSHOT.jar To build a war file that is both executable and deployable into an external container you need to mark the embedded container dependencies as “provided”, e.g: war org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-tomcat provided Tip See the “Section 82.1, “Create a deployable war file”” section for more details on how to create a deployable war file. Advanced configuration options and examples are available in the plugin info page. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 201 66. Spring Boot Gradle plugin The Spring Boot Gradle Plugin provides Spring Boot support in Gradle, allowing you to package executable jar or war archives, run Spring Boot applications and use the dependency management provided by spring-boot-dependencies. 66.1 Including the plugin To use the Spring Boot Gradle Plugin simply include a buildscript dependency and apply the spring-boot plugin: buildscript { dependencies { classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.0.BUILD-SNAPSHOT") } } apply plugin: 'spring-boot' If you are using a milestone or snapshot release you will also need to add appropriate repositories reference: buildscript { repositories { maven.url "http://repo.spring.io/snapshot" maven.url "http://repo.spring.io/milestone" } // ... } 66.2 Gradle dependency management The spring-boot plugin automatically applies the Dependency Management Plugin and configures in to import the spring-boot-starter-parent bom. This provides a similar dependency management experience to the one that is enjoyed by Maven users. For example, it allows you to omit version numbers when declaring dependencies that are managed in the bom. To make use of this functionality, simply declare dependencies in the usual way, but leave the version number empty: dependencies { compile("org.springframework.boot:spring-boot-starter-web") compile("org.thymeleaf:thymeleaf-spring4") compile("nz.net.ultraq.thymeleaf:thymeleaf-layout-dialect") } Note The version of the spring-boot gradle plugin that you declare determines the version of the spring-boot-starter-parent bom that is imported (this ensures that builds are always repeatable). You should always set the version of the spring-boot gradle plugin to the actual Spring Boot version that you wish to use. Details of the versions that are provided can be found in the appendix. The dependency management plugin will only supply a version where one is not specified. To use a version of an artifact that differs from the one that the plugin would provide, simply specify the version when you declare the dependency as you usually would. For example: dependencies { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 202 compile("org.thymeleaf:thymeleaf-spring4:2.1.1.RELEASE") } To learn more about the capabilities of the Dependency Management Plugin, please refer to its documentation. 66.3 Packaging executable jar and war files Once the spring-boot plugin has been applied to your project it will automatically attempt to rewrite archives to make them executable using the bootRepackage task. You should configure your project to build a jar or war (as appropriate) in the usual way. The main class that you want to launch can either be specified using a configuration option, or by adding a Main-Class attribute to the manifest. If you don’t specify a main class the plugin will search for a class with a public static void main(String[] args) method. Tip Check Section 66.6, “Repackage configuration” for a full list of configuration options. To build and run a project artifact, you can type the following: $ gradle build $ java -jar build/libs/mymodule-0.0.1-SNAPSHOT.jar To build a war file that is both executable and deployable into an external container, you need to mark the embedded container dependencies as belonging to a configuration named “providedRuntime”, e.g: ... apply plugin: 'war' war { baseName = 'myapp' version = '0.5.0' } repositories { jcenter() maven { url "http://repo.spring.io/libs-snapshot" } } configurations { providedRuntime } dependencies { compile("org.springframework.boot:spring-boot-starter-web") providedRuntime("org.springframework.boot:spring-boot-starter-tomcat") ... } Tip See the “Section 82.1, “Create a deployable war file”” section for more details on how to create a deployable war file. 66.4 Running a project in-place To run a project in place without building a jar first you can use the “bootRun” task: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 203 $ gradle bootRun If devtools has been added to your project it will automatically monitor your application for changes. Alternatively, you can also run the application so that your static classpath resources (i.e. in src/main/ resources by default) are reloadable in the live application, which can be helpful at development time. bootRun { addResources = true } Making static classpath resources reloadable means that bootRun does not use the output of the processResources task, i.e., when invoked using bootRun, your application will use the resources in their unprocessed form. 66.5 Spring Boot plugin configuration The gradle plugin automatically extends your build script DSL with a springBoot element for global configuration of the Boot plugin. Set the appropriate properties as you would with any other Gradle extension (see below for a list of configuration options): springBoot { backupSource = false } 66.6 Repackage configuration The plugin adds a bootRepackage task which you can also configure directly, e.g.: bootRepackage { mainClass = 'demo.Application' } The following configuration options are available: Name Description enabled Boolean flag to switch the repackager off (sometimes useful if you want the other Boot features but not this one) mainClass The main class that should be run. If not specified, and you have applied the application plugin, the mainClassName project property will be used. If the application plugin has not been applied or no mainClassName has been specified, the archive will be searched for a suitable class. "Suitable" means a unique class with a well-formed main() method (if more than one is found the build will fail). If you have applied the application plugin, the main class can also be specified via its "run" task (main property) and/or its "startScripts" task (mainClassName property) as an alternative to using the "springBoot" configuration. classifier A file name segment (before the extension) to add to the archive, so that the original is preserved in its original location. Defaults to null in which case the archive is repackaged in place. The default is convenient for many purposes, but if you want to use Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 204 Name Description the original jar as a dependency in another project, it’s best to use an extension to define the executable archive. withJarTask The name or value of the Jar task (defaults to all tasks of type Jar) which is used to locate the archive to repackage. customConfiguration The name of the custom configuration which is used to populate the nested lib directory (without specifying this you get all compile and runtime dependencies). executable Boolean flag to indicate if jar files are fully executable on Unix like operating systems. Defaults to false. embeddedLaunchScript The embedded launch script to prepend to the front of the jar if it is fully executable. If not specified the 'Spring Boot' default script will be used. embeddedLaunchScriptPropertiesAdditional properties that to be expanded in the launch script. The default script supports a mode property which can contain the values auto, service or run. excludeDevtools Boolean flag to indicate if the devtools jar should be excluded from the repackaged archives. Defaults to false. 66.7 Repackage with custom Gradle configuration Sometimes it may be more appropriate to not package default dependencies resolved from compile, runtime and provided scopes. If the created executable jar file is intended to be run as it is, you need to have all dependencies nested inside it; however, if the plan is to explode a jar file and run the main class manually, you may already have some of the libraries available via CLASSPATH. This is a situation where you can repackage your jar with a different set of dependencies. Using a custom configuration will automatically disable dependency resolving from compile, runtime and provided scopes. Custom configuration can be either defined globally (inside the springBoot section) or per task. task clientJar(type: Jar) { appendix = 'client' from sourceSets.main.output exclude('**/*Something*') } task clientBoot(type: BootRepackage, dependsOn: clientJar) { withJarTask = clientJar customConfiguration = "mycustomconfiguration" } In above example, we created a new clientJar Jar task to package a customized file set from your compiled sources. Then we created a new clientBoot BootRepackage task and instructed it to work with only clientJar task and mycustomconfiguration. configurations { mycustomconfiguration.exclude group: 'log4j' } dependencies { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 205 mycustomconfiguration configurations.runtime } The configuration that we are referring to in BootRepackage is a normal Gradle configuration. In the above example we created a new configuration named mycustomconfiguration instructing it to derive from a runtime and exclude the log4j group. If the clientBoot task is executed, the repackaged boot jar will have all dependencies from runtime but no log4j jars. Configuration options The following configuration options are available: Name Description mainClass The main class that should be run by the executable archive. providedConfiguration The name of the provided configuration (defaults to providedRuntime). backupSource If the original source archive should be backed-up before being repackaged (defaults to true). customConfiguration The name of the custom configuration. layout The type of archive, corresponding to how the dependencies are laid out inside (defaults to a guess based on the archive type). requiresUnpack A list of dependencies (in the form “groupId:artifactId” that must be unpacked from fat jars in order to run. Items are still packaged into the fat jar, but they will be automatically unpacked when it runs. 66.8 Understanding how the Gradle plugin works When spring-boot is applied to your Gradle project a default task named bootRepackage is created automatically. The bootRepackage task depends on Gradle assemble task, and when executed, it tries to find all jar artifacts whose qualifier is empty (i.e. tests and sources jars are automatically skipped). Due to the fact that bootRepackage finds 'all' created jar artifacts, the order of Gradle task execution is important. Most projects only create a single jar file, so usually this is not an issue; however, if you are planning to create a more complex project setup, with custom Jar and BootRepackage tasks, there are few tweaks to consider. If you are 'just' creating custom jar files from your project you can simply disable default jar and bootRepackage tasks: jar.enabled = false bootRepackage.enabled = false Another option is to instruct the default bootRepackage task to only work with a default jar task. bootRepackage.withJarTask = jar If you have a default project setup where the main jar file is created and repackaged, 'and' you still want to create additional custom jars, you can combine your custom repackage tasks together and use dependsOn so that the bootJars task will run after the default bootRepackage task is executed: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 206 task bootJars bootJars.dependsOn = [clientBoot1,clientBoot2,clientBoot3] build.dependsOn(bootJars) All the above tweaks are usually used to avoid situations where an already created boot jar is repackaged again. Repackaging an existing boot jar will not break anything, but you may find that it includes unnecessary dependencies. 66.9 Publishing artifacts to a Maven repository using Gradle If you are declaring dependencies without versions and you want to publish artifacts to a Maven repository you will need to configure the Maven publication with details of Spring Boot’s dependency management. This can be achieved by configuring it to publish poms that inherit from spring-boot- starter-parent or that import dependency management from spring-boot-dependencies. The exact details of this configuration depend on how you’re using Gradle and how you’re trying to publish the artifacts. Configuring Gradle to produce a pom that inherits dependency management The following is an example of configuring Gradle to generate a pom that inherits from spring-boot- starter-parent. Please refer to the Gradle User Guide for further information. uploadArchives { repositories { mavenDeployer { pom { project { parent { groupId "org.springframework.boot" artifactId "spring-boot-starter-parent" version "1.4.0.BUILD-SNAPSHOT" } } } } } } Configuring Gradle to produce a pom that imports dependency management The following is an example of configuring Gradle to generate a pom that imports the dependency management provided by spring-boot-dependencies. Please refer to the Gradle User Guide for further information. uploadArchives { repositories { mavenDeployer { pom { project { dependencyManagement { dependencies { dependency { groupId "org.springframework.boot" artifactId "spring-boot-dependencies" version "1.4.0.BUILD-SNAPSHOT" type "pom" scope "import" } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 207 } } } } } } } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 208 67. Spring Boot AntLib module The Spring Boot AntLib module provides basic Spring Boot support for Apache Ant. You can use the module to create executable jars. To use the module you need to declare an additional spring-boot namespace in your build.xml: ... You’ll need to remember to start Ant using the -lib option, for example: $ ant -lib Tip The “Using Spring Boot” section includes a more complete example of using Apache Ant with spring-boot-antlib 67.1 Spring Boot Ant tasks Once the spring-boot-antlib namespace has been declared, the following additional tasks are available. spring-boot:exejar The exejar task can be used to creates a Spring Boot executable jar. The following attributes are supported by the task: Attribute Description Required destfile The destination jar file to create Yes classes The root directory of Java class files Yes start-class The main application class to run No (default is first class found declaring a main method) The following nested elements can be used with the task: Element Description resources One or more Resource Collections describing a set of Resources that should be added to the content of the created jar file. lib One or more Resource Collections that should be added to the set of jar libraries that make up the runtime dependency classpath of the application. Examples Specify start-class. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 209 Detect start-class. 67.2 spring-boot:findmainclass The findmainclass task is used internally by exejar to locate a class declaring a main. You can also use this task directly in your build if needed. The following attributes are supported Attribute Description Required classesroot The root directory of Java class files Yes (unless mainclass is specified) mainclass Can be used to short-circuit the main class search No property The Ant property that should be set with the result No (result will be logged if unspecified) Examples Find and log. Find and set. Override and set. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 210 68. Supporting other build systems If you want to use a build tool other than Maven, Gradle or Ant, you will likely need to develop your own plugin. Executable jars need to follow a specific format and certain entries need to be written in an uncompressed form (see the executable jar format section in the appendix for details). The Spring Boot Maven and Gradle plugins both make use of spring-boot-loader-tools to actually generate jars. You are also free to use this library directly yourself if you need to. 68.1 Repackaging archives To repackage an existing archive so that it becomes a self-contained executable archive use org.springframework.boot.loader.tools.Repackager. The Repackager class takes a single constructor argument that refers to an existing jar or war archive. Use one of the two available repackage() methods to either replace the original file or write to a new destination. Various settings can also be configured on the repackager before it is run. 68.2 Nested libraries When repackaging an archive you can include references to dependency files using the org.springframework.boot.loader.tools.Libraries interface. We don’t provide any concrete implementations of Libraries here as they are usually build system specific. If your archive already includes libraries you can use Libraries.NONE. 68.3 Finding a main class If you don’t use Repackager.setMainClass() to specify a main class, the repackager will use ASM to read class files and attempt to find a suitable class with a public static void main(String[] args) method. An exception is thrown if more than one candidate is found. 68.4 Example repackage implementation Here is a typical example repackage: Repackager repackager = new Repackager(sourceJarFile); repackager.setBackupSource(false); repackager.repackage(new Libraries() { @Override public void doWithLibraries(LibraryCallback callback) throws IOException { // Build system specific implementation, callback for each dependency // callback.library(new Library(nestedFile, LibraryScope.COMPILE)); } }); Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 211 69. What to read next If you’re interested in how the build tool plugins work you can look at the spring-boot-tools module on GitHub. More technical details of the executable jar format are covered in the appendix. If you have specific build-related questions you can check out the “how-to” guides. Part IX. ‘How-to’ guides This section provides answers to some common ‘how do I do that…’ type of questions that often arise when using Spring Boot. This is by no means an exhaustive list, but it does cover quite a lot. If you are having a specific problem that we don’t cover here, you might want to check out stackoverflow.com to see if someone has already provided an answer; this is also a great place to ask new questions (please use the spring-boot tag). We’re also more than happy to extend this section; If you want to add a ‘how-to’ you can send us a pull request. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 213 70. Spring Boot application 70.1 Troubleshoot auto-configuration The Spring Boot auto-configuration tries its best to ‘do the right thing’, but sometimes things fail and it can be hard to tell why. There is a really useful ConditionEvaluationReport available in any Spring Boot ApplicationContext. You will see it if you enable DEBUG logging output. If you use the spring- boot-actuator there is also an autoconfig endpoint that renders the report in JSON. Use that to debug the application and see what features have been added (and which not) by Spring Boot at runtime. Many more questions can be answered by looking at the source code and the Javadoc. Some rules of thumb: • Look for classes called *AutoConfiguration and read their sources, in particular the @Conditional* annotations to find out what features they enable and when. Add --debug to the command line or a System property -Ddebug to get a log on the console of all the auto-configuration decisions that were made in your app. In a running Actuator app look at the autoconfig endpoint (‘/autoconfig’ or the JMX equivalent) for the same information. • Look for classes that are @ConfigurationProperties (e.g. ServerProperties) and read from there the available external configuration options. The @ConfigurationProperties has a name attribute which acts as a prefix to external properties, thus ServerProperties has prefix="server" and its configuration properties are server.port, server.address etc. In a running Actuator app look at the configprops endpoint. • Look for use of RelaxedPropertyResolver to pull configuration values explicitly out of the Environment. It often is used with a prefix. • Look for @Value annotations that bind directly to the Environment. This is less flexible than the RelaxedPropertyResolver approach, but does allow some relaxed binding, specifically for OS environment variables (so CAPITALS_AND_UNDERSCORES are synonyms for period.separated). • Look for @ConditionalOnExpression annotations that switch features on and off in response to SpEL expressions, normally evaluated with placeholders resolved from the Environment. 70.2 Customize the Environment or ApplicationContext before it starts A SpringApplication has ApplicationListeners and ApplicationContextInitializers that are used to apply customizations to the context or environment. Spring Boot loads a number of such customizations for use internally from META-INF/spring.factories. There is more than one way to register additional ones: • Programmatically per application by calling the addListeners and addInitializers methods on SpringApplication before you run it. • Declaratively per application by setting context.initializer.classes or context.listener.classes. • Declaratively for all applications by adding a META-INF/spring.factories and packaging a jar file that the applications all use as a library. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 214 The SpringApplication sends some special ApplicationEvents to the listeners (even some before the context is created), and then registers the listeners for events published by the ApplicationContext as well. See Section 23.4, “Application events and listeners” in the ‘Spring Boot features’ section for a complete list. 70.3 Build an ApplicationContext hierarchy (adding a parent or root context) You can use the ApplicationBuilder class to create parent/child ApplicationContext hierarchies. See Section 23.3, “Fluent builder API” in the ‘Spring Boot features’ section for more information. 70.4 Create a non-web application Not all Spring applications have to be web applications (or web services). If you want to execute some code in a main method, but also bootstrap a Spring application to set up the infrastructure to use, then it’s easy with the SpringApplication features of Spring Boot. A SpringApplication changes its ApplicationContext class depending on whether it thinks it needs a web application or not. The first thing you can do to help it is to just leave the servlet API dependencies off the classpath. If you can’t do that (e.g. you are running 2 applications from the same code base) then you can explicitly call setWebEnvironment(false) on your SpringApplication instance, or set the applicationContextClass property (through the Java API or with external properties). Application code that you want to run as your business logic can be implemented as a CommandLineRunner and dropped into the context as a @Bean definition. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 215 71. Properties & configuration 71.1 Automatically expand properties at build time Rather than hardcoding some properties that are also specified in your project’s build configuration, you can automatically expand them using the existing build configuration instead. This is possible in both Maven and Gradle. Automatic property expansion using Maven You can automatically expand properties from the Maven project using resource filtering. If you use the spring-boot-starter-parent you can then refer to your Maven ‘project properties’ via @..@ placeholders, e.g. app.encoding=@project.build.sourceEncoding@ app.java.version=@java.version@ Tip The spring-boot:run can add src/main/resources directly to the classpath (for hot reloading purposes) if you enable the addResources flag. This circumvents the resource filtering and this feature. You can use the exec:java goal instead or customize the plugin’s configuration, see the plugin usage page for more details. If you don’t use the starter parent, in your pom.xml you need (inside the element): src/main/resources true and (inside ): org.apache.maven.plugins maven-resources-plugin 2.7 @ false Note The useDefaultDelimiters property is important if you are using standard Spring placeholders in your configuration (e.g. ${foo}). These may be expanded by the build if that property is not set to false. Automatic property expansion using Gradle You can automatically expand properties from the Gradle project by configuring the Java plugin’s processResources task to do so: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 216 processResources { expand(project.properties) } You can then refer to your Gradle project’s properties via placeholders, e.g. app.name=${name} app.description=${description} Note Gradle’s expand method uses Groovy’s SimpleTemplateEngine which transforms ${..} tokens. The ${..} style conflicts with Spring’s own property placeholder mechanism. To use Spring property placeholders together with automatic expansion the Spring property placeholders need to be escaped like \${..}. 71.2 Externalize the configuration of SpringApplication A SpringApplication has bean properties (mainly setters) so you can use its Java API as you create the application to modify its behavior. Or you can externalize the configuration using properties in spring.main.*. E.g. in application.properties you might have. spring.main.web-environment=false spring.main.banner-mode=off and then the Spring Boot banner will not be printed on startup, and the application will not be a web application. Note The example above also demonstrates how flexible binding allows the use of underscores (_) as well as dashes (-) in property names. Properties defined in external configuration overrides the values specified via the Java API with the notable exception of the sources used to create the ApplicationContext. Let’s consider this application new SpringApplicationBuilder() .bannerMode(Banner.Mode.OFF) .sources(demo.MyApp.class) .run(args); used with the following configuration: spring.main.sources=com.acme.Config,com.acme.ExtraConfig spring.main.banner-mode=console The actual application will now show the banner (as overridden by configuration) and use three sources for the ApplicationContext (in that order): demo.MyApp, com.acme.Config, com.acme.ExtraConfig. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 217 71.3 Change the location of external properties of an application By default properties from different sources are added to the Spring Environment in a defined order (see Chapter 24, Externalized Configuration in the ‘Spring Boot features’ section for the exact order). A nice way to augment and modify this is to add @PropertySource annotations to your application sources. Classes passed to the SpringApplication static convenience methods, and those added using setSources() are inspected to see if they have @PropertySources, and if they do, those properties are added to the Environment early enough to be used in all phases of the ApplicationContext lifecycle. Properties added in this way have lower priority than any added using the default locations (e.g. application.properties), system properties, environment variables or the command line. You can also provide System properties (or environment variables) to change the behavior: • spring.config.name (SPRING_CONFIG_NAME), defaults to application as the root of the file name. • spring.config.location (SPRING_CONFIG_LOCATION) is the file to load (e.g. a classpath resource or a URL). A separate Environment property source is set up for this document and it can be overridden by system properties, environment variables or the command line. No matter what you set in the environment, Spring Boot will always load application.properties as described above. If YAML is used then files with the ‘.yml’ extension are also added to the list by default. Spring Boot logs the configuration files that are loaded at DEBUG level and the candidates it has not found at TRACE level. See ConfigFileApplicationListener for more detail. 71.4 Use ‘short’ command line arguments Some people like to use (for example) --port=9000 instead of --server.port=9000 to set configuration properties on the command line. You can easily enable this by using placeholders in application.properties, e.g. server.port=${port:8080} Tip If you are inheriting from the spring-boot-starter-parent POM, the default filter token of the maven-resources-plugins has been changed from ${*} to @ (i.e. @maven.token@ instead of ${maven.token}) to prevent conflicts with Spring-style placeholders. If you have enabled maven filtering for the application.properties directly, you may want to also change the default filter token to use other delimiters. Note In this specific case the port binding will work in a PaaS environment like Heroku and Cloud Foundry, since in those two platforms the PORT environment variable is set automatically and Spring can bind to capitalized synonyms for Environment properties. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 218 71.5 Use YAML for external properties YAML is a superset of JSON and as such is a very convenient syntax for storing external properties in a hierarchical format. E.g. spring: application: name: cruncher datasource: driverClassName: com.mysql.jdbc.Driver url: jdbc:mysql://localhost/test server: port: 9000 Create a file called application.yml and stick it in the root of your classpath, and also add snakeyaml to your dependencies (Maven coordinates org.yaml:snakeyaml, already included if you use the spring-boot-starter). A YAML file is parsed to a Java Map (like a JSON object), and Spring Boot flattens the map so that it is 1-level deep and has period-separated keys, a lot like people are used to with Properties files in Java. The example YAML above corresponds to an application.properties file spring.application.name=cruncher spring.datasource.driverClassName=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost/test server.port=9000 See Section 24.6, “Using YAML instead of Properties” in the ‘Spring Boot features’ section for more information about YAML. 71.6 Set the active Spring profiles The Spring Environment has an API for this, but normally you would set a System property (spring.profiles.active) or an OS environment variable (SPRING_PROFILES_ACTIVE). E.g. launch your application with a -D argument (remember to put it before the main class or jar archive): $ java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar In Spring Boot you can also set the active profile in application.properties, e.g. spring.profiles.active=production A value set this way is replaced by the System property or environment variable setting, but not by the SpringApplicationBuilder.profiles() method. Thus the latter Java API can be used to augment the profiles without changing the defaults. See Chapter 25, Profiles in the ‘Spring Boot features’ section for more information. 71.7 Change configuration depending on the environment A YAML file is actually a sequence of documents separated by --- lines, and each document is parsed separately to a flattened map. If a YAML document contains a spring.profiles key, then the profiles value (comma-separated list of profiles) is fed into the Spring Environment.acceptsProfiles() and if any of those profiles is active that document is included in the final merge (otherwise not). Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 219 Example: server: port: 9000 --- spring: profiles: development server: port: 9001 --- spring: profiles: production server: port: 0 In this example the default port is 9000, but if the Spring profile ‘development’ is active then the port is 9001, and if ‘production’ is active then it is 0. The YAML documents are merged in the order they are encountered (so later values override earlier ones). To do the same thing with properties files you can use application-${profile}.properties to specify profile-specific values. 71.8 Discover built-in options for external properties Spring Boot binds external properties from application.properties (or .yml) (and other places) into an application at runtime. There is not (and technically cannot be) an exhaustive list of all supported properties in a single location because contributions can come from additional jar files on your classpath. A running application with the Actuator features has a configprops endpoint that shows all the bound and bindable properties available through @ConfigurationProperties. The appendix includes an application.properties example with a list of the most common properties supported by Spring Boot. The definitive list comes from searching the source code for @ConfigurationProperties and @Value annotations, as well as the occasional use of RelaxedPropertyResolver. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 220 72. Embedded servlet containers 72.1 Add a Servlet, Filter or Listener to an application There are two ways to add Servlet, Filter, ServletContextListener and the other listeners supported by the Servlet spec to your application. You can either provide Spring beans for them, or enable scanning for Servlet components. Add a Servlet, Filter or Listener using a Spring bean To add a Servlet, Filter, or Servlet *Listener provide a @Bean definition for it. This can be very useful when you want to inject configuration or dependencies. However, you must be very careful that they don’t cause eager initialization of too many other beans because they have to be installed in the container very early in the application lifecycle (e.g. it’s not a good idea to have them depend on your DataSource or JPA configuration). You can work around restrictions like that by initializing them lazily when first used instead of on initialization. In the case of Filters and Servlets you can also add mappings and init parameters by adding a FilterRegistrationBean or ServletRegistrationBean instead of or as well as the underlying component. Note If no dispatcherType is specified on a filter registration, it will match FORWARD,INCLUDE and REQUEST. If async has been enabled, it will match ASYNC as well. If you are migrating a filter that has no dispatcher element in web.xml you will need to specify a dispatcherType yourself: @Bean public FilterRegistrationBean myFilterRegistration() { FilterRegistrationBean registration = new FilterRegistrationBean(); registration.setDispatcherTypes(DispatcherType.REQUEST); .... return registration; } Disable registration of a Servlet or Filter As described above any Servlet or Filter beans will be registered with the servlet container automatically. To disable registration of a particular Filter or Servlet bean create a registration bean for it and mark it as disabled. For example: @Bean public FilterRegistrationBean registration(MyFilter filter) { FilterRegistrationBean registration = new FilterRegistrationBean(filter); registration.setEnabled(false); return registration; } Add Servlets, Filters, and Listeners using classpath scanning @WebServlet, @WebFilter, and @WebListener annotated classes can be automatically registered with an embedded servlet container by annotating a @Configuration class with Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 221 @ServletComponentScan and specifying the package(s) containing the components that you want to register. By default, @ServletComponentScan will scan from the package of the annotated class. 72.2 Change the HTTP port In a standalone application the main HTTP port defaults to 8080, but can be set with server.port (e.g. in application.properties or as a System property). Thanks to relaxed binding of Environment values you can also use SERVER_PORT (e.g. as an OS environment variable). To switch off the HTTP endpoints completely, but still create a WebApplicationContext, use server.port=-1 (this is sometimes useful for testing). For more details look at the section called “Customizing embedded servlet containers” in the ‘Spring Boot features’ section, or the ServerProperties source code. 72.3 Use a random unassigned HTTP port To scan for a free port (using OS natives to prevent clashes) use server.port=0. 72.4 Discover the HTTP port at runtime You can access the port the server is running on from log output or from the EmbeddedWebApplicationContext via its EmbeddedServletContainer. The best way to get that and be sure that it has initialized is to add a @Bean of type ApplicationListener and pull the container out of the event when it is published. Tests that use @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) can also inject the actual port into a field using the @LocalServerPort annotation. For example: @RunWith(SpringJUnit4ClassRunner.class) @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) public class MyWebIntegrationTests { @Autowired EmbeddedWebApplicationContext server; @LocalServerPort int port; // ... } Note @LocalServerPort is a meta-annotation for @Value("${local.server.port}"). Don’t try to inject the port in a regular application. As we just saw, the value is only set once the container has initialized; contrary to a test, application code callbacks are processed early (i.e. before the value is actually available). 72.5 Configure SSL SSL can be configured declaratively by setting the various server.ssl.* properties, typically in application.properties or application.yml. For example: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 222 server.port=8443 server.ssl.key-store=classpath:keystore.jks server.ssl.key-store-password=secret server.ssl.key-password=another-secret See Ssl for details of all of the supported properties. Using configuration like the example above means the application will no longer support plain HTTP connector at port 8080. Spring Boot doesn’t support the configuration of both an HTTP connector and an HTTPS connector via application.properties. If you want to have both then you’ll need to configure one of them programmatically. It’s recommended to use application.properties to configure HTTPS as the HTTP connector is the easier of the two to configure programmatically. See the spring-boot-sample-tomcat-multi-connectors sample project for an example. 72.6 Configure Access Logging Access logs can be configured for Tomcat and Undertow via their respective namespaces. For instance, the following logs access on Tomcat with a custom pattern. server.tomcat.basedir=my-tomcat server.tomcat.accesslog.enabled=true server.tomcat.accesslog.pattern=%t %a "%r" %s (%D ms) Note The default location for logs is a logs directory relative to the tomcat base dir and said directory is a temp directory by default so you may want to fix Tomcat’s base directory or use an absolute path for the logs. In the example above, the logs will be available in my-tomcat/logs relative to the working directory of the application. Access logging for undertow can be configured in a similar fashion server.undertow.accesslog.enabled=true server.undertow.accesslog.pattern=%t %a "%r" %s (%D ms) Logs are stored in a logs directory relative to the working directory of the application. This can be customized via server.undertow.accesslog.directory. 72.7 Use behind a front-end proxy server Your application might need to send 302 redirects or render content with absolute links back to itself. When running behind a proxy, the caller wants a link to the proxy, and not to the physical address of the machine hosting your app. Typically such situations are handled via a contract with the proxy, which will add headers to tell the back end how to construct links to itself. If the proxy adds conventional X-Forwarded-For and X-Forwarded-Proto headers (most do this out of the box) the absolute links should be rendered correctly as long as server.use-forward- headers is set to true in your application.properties. Note If your application is running in Cloud Foundry or Heroku the server.use-forward-headers property will default to true if not specified. In all other instances it defaults to false. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 223 Customize Tomcat’s proxy configuration If you are using Tomcat you can additionally configure the names of the headers used to carry “forwarded” information: server.tomcat.remote-ip-header=x-your-remote-ip-header server.tomcat.protocol-header=x-your-protocol-header Tomcat is also configured with a default regular expression that matches internal proxies that are to be trusted. By default, IP addresses in 10/8, 192.168/16, 169.254/16 and 127/8 are trusted. You can customize the valve’s configuration by adding an entry to application.properties, e.g. server.tomcat.internal-proxies=192\\.168\\.\\d{1,3}\\.\\d{1,3} Note The double backslashes are only required when you’re using a properties file for configuration. If you are using YAML, single backslashes are sufficient and a value that’s equivalent to the one shown above would be 192\.168\.\d{1,3}\.\d{1,3}. Note You can trust all proxies by setting the internal-proxies to empty (but don’t do this in production). You can take complete control of the configuration of Tomcat’s RemoteIpValve by switching the automatic one off (i.e. set server.use-forward-headers=false) and adding a new valve instance in a TomcatEmbeddedServletContainerFactory bean. 72.8 Configure Tomcat Generally you can follow the advice from Section 71.8, “Discover built-in options for external properties” about @ConfigurationProperties (ServerProperties is the main one here), but also look at EmbeddedServletContainerCustomizer and various Tomcat-specific *Customizers that you can add in one of those. The Tomcat APIs are quite rich so once you have access to the TomcatEmbeddedServletContainerFactory you can modify it in a number of ways. Or the nuclear option is to add your own TomcatEmbeddedServletContainerFactory. 72.9 Enable Multiple Connectors with Tomcat Add a org.apache.catalina.connector.Connector to the TomcatEmbeddedServletContainerFactory which can allow multiple connectors, e.g. HTTP and HTTPS connector: @Bean public EmbeddedServletContainerFactory servletContainer() { TomcatEmbeddedServletContainerFactory tomcat = new TomcatEmbeddedServletContainerFactory(); tomcat.addAdditionalTomcatConnectors(createSslConnector()); return tomcat; } private Connector createSslConnector() { Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol"); Http11NioProtocol protocol = (Http11NioProtocol) connector.getProtocolHandler(); try { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 224 File keystore = new ClassPathResource("keystore").getFile(); File truststore = new ClassPathResource("keystore").getFile(); connector.setScheme("https"); connector.setSecure(true); connector.setPort(8443); protocol.setSSLEnabled(true); protocol.setKeystoreFile(keystore.getAbsolutePath()); protocol.setKeystorePass("changeit"); protocol.setTruststoreFile(truststore.getAbsolutePath()); protocol.setTruststorePass("changeit"); protocol.setKeyAlias("apitester"); return connector; } catch (IOException ex) { throw new IllegalStateException("can't access keystore: [" + "keystore" + "] or truststore: [" + "keystore" + "]", ex); } } 72.10 Use Jetty instead of Tomcat The Spring Boot starters (spring-boot-starter-web in particular) use Tomcat as an embedded container by default. You need to exclude those dependencies and include the Jetty one instead. Spring Boot provides Tomcat and Jetty dependencies bundled together as separate starters to help make this process as easy as possible. Example in Maven: org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-tomcat org.springframework.boot spring-boot-starter-jetty Example in Gradle: configurations { compile.exclude module: "spring-boot-starter-tomcat" } dependencies { compile("org.springframework.boot:spring-boot-starter-web:1.4.0.BUILD-SNAPSHOT") compile("org.springframework.boot:spring-boot-starter-jetty:1.4.0.BUILD-SNAPSHOT") // ... } 72.11 Configure Jetty Generally you can follow the advice from Section 71.8, “Discover built-in options for external properties” about @ConfigurationProperties (ServerProperties is the main one here), but also look at EmbeddedServletContainerCustomizer. The Jetty APIs are quite rich so once you have access to the JettyEmbeddedServletContainerFactory you can modify it in a number of ways. Or the nuclear option is to add your own JettyEmbeddedServletContainerFactory. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 225 72.12 Use Undertow instead of Tomcat Using Undertow instead of Tomcat is very similar to using Jetty instead of Tomcat. You need to exclude the Tomcat dependencies and include the Undertow starter instead. Example in Maven: org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-tomcat org.springframework.boot spring-boot-starter-undertow Example in Gradle: configurations { compile.exclude module: "spring-boot-starter-tomcat" } dependencies { compile("org.springframework.boot:spring-boot-starter-web:1.4.0.BUILD-SNAPSHOT") compile("org.springframework.boot:spring-boot-starter-undertow:1.4.0.BUILD-SNAPSHOT") // ... } 72.13 Configure Undertow Generally you can follow the advice from Section 71.8, “Discover built-in options for external properties” about @ConfigurationProperties (ServerProperties and ServerProperties.Undertow are the main ones here), but also look at EmbeddedServletContainerCustomizer. Once you have access to the UndertowEmbeddedServletContainerFactory you can use an UndertowBuilderCustomizer to modify Undertow’s configuration to meet your needs. Or the nuclear option is to add your own UndertowEmbeddedServletContainerFactory. 72.14 Enable Multiple Listeners with Undertow Add an UndertowBuilderCustomizer to the UndertowEmbeddedServletContainerFactory and add a listener to the Builder: @Bean public UndertowEmbeddedServletContainerFactory embeddedServletContainerFactory() { UndertowEmbeddedServletContainerFactory factory = new UndertowEmbeddedServletContainerFactory(); factory.addBuilderCustomizers(new UndertowBuilderCustomizer() { @Override public void customize(Builder builder) { builder.addHttpListener(8080, "0.0.0.0"); } }); return factory; } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 226 72.15 Use Tomcat 7 Tomcat 7 works with Spring Boot, but the default is to use Tomcat 8. If you cannot use Tomcat 8 (for example, because you are using Java 1.6) you will need to change your classpath to reference Tomcat 7 . Use Tomcat 7 with Maven If you are using the starters and parent you can just change the Tomcat version property, e.g. for a simple webapp or service: 7.0.59 ... org.springframework.boot spring-boot-starter-web ... Use Tomcat 7 with Gradle You can change the Tomcat version by setting the tomcat.version property: ext['tomcat.version'] = '7.0.59' dependencies { compile 'org.springframework.boot:spring-boot-starter-web' } 72.16 Use Jetty 8 Jetty 8 works with Spring Boot, but the default is to use Jetty 9. If you cannot use Jetty 9 (for example, because you are using Java 1.6) you will need to change your classpath to reference Jetty 8. You will also need to exclude Jetty’s WebSocket-related dependencies. Use Jetty 8 with Maven If you are using the starters and parent you can just add the Jetty starter with the required WebSocket exclusion and change the version properties, e.g. for a simple webapp or service: 8.1.15.v20140411 2.2.0.v201112011158 org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-tomcat org.springframework.boot spring-boot-starter-jetty Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 227 org.eclipse.jetty.websocket * Use Jetty 8 with Gradle You can set the jetty.version property and exclude the WebSocket dependency, e.g. for a simple webapp or service: ext['jetty.version'] = '8.1.15.v20140411' dependencies { compile ('org.springframework.boot:spring-boot-starter-web') { exclude group: 'org.springframework.boot', module: 'spring-boot-starter-tomcat' } compile ('org.springframework.boot:spring-boot-starter-jetty') { exclude group: 'org.eclipse.jetty.websocket' } } 72.17 Create WebSocket endpoints using @ServerEndpoint If you want to use @ServerEndpoint in a Spring Boot application that used an embedded container, you must declare a single ServerEndpointExporter @Bean: @Bean public ServerEndpointExporter serverEndpointExporter() { return new ServerEndpointExporter(); } This bean will register any @ServerEndpoint annotated beans with the underlying WebSocket container. When deployed to a standalone servlet container this role is performed by a servlet container initializer and the ServerEndpointExporter bean is not required. 72.18 Enable HTTP response compression HTTP response compression is supported by Jetty, Tomcat, and Undertow. It can be enabled via application.properties: server.compression.enabled=true By default, responses must be at least 2048 bytes in length for compression to be performed. This can be configured using the server.compression.min-response-size property. By default, responses will only be compressed if their content type is one of the following: • text/html • text/xml • text/plain • text/css This can be configured using the server.compression.mime-types property. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 228 73. Spring MVC 73.1 Write a JSON REST service Any Spring @RestController in a Spring Boot application should render JSON response by default as long as Jackson2 is on the classpath. For example: @RestController public class MyController { @RequestMapping("/thing") public MyThing thing() { return new MyThing(); } } As long as MyThing can be serialized by Jackson2 (e.g. a normal POJO or Groovy object) then localhost:8080/thing will serve a JSON representation of it by default. Sometimes in a browser you might see XML responses because browsers tend to send accept headers that prefer XML. 73.2 Write an XML REST service If you have the Jackson XML extension (jackson-dataformat-xml) on the classpath, it will be used to render XML responses and the very same example as we used for JSON would work. To use it, add the following dependency to your project: com.fasterxml.jackson.dataformat jackson-dataformat-xml You may also want to add a dependency on Woodstox. It’s faster than the default StAX implementation provided by the JDK and also adds pretty print support and improved namespace handling: org.codehaus.woodstox woodstox-core-asl If Jackson’s XML extension is not available, JAXB (provided by default in the JDK) will be used, with the additional requirement to have MyThing annotated as @XmlRootElement: @XmlRootElement public class MyThing { private String name; // .. getters and setters } To get the server to render XML instead of JSON you might have to send an Accept: text/xml header (or use a browser). 73.3 Customize the Jackson ObjectMapper Spring MVC (client and server side) uses HttpMessageConverters to negotiate content conversion in an HTTP exchange. If Jackson is on the classpath you already get the default converter(s) provided by Jackson2ObjectMapperBuilder. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 229 The ObjectMapper (or XmlMapper for Jackson XML converter) instance created by default have the following customized properties: • MapperFeature.DEFAULT_VIEW_INCLUSION is disabled • DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES is disabled Spring Boot has also some features to make it easier to customize this behavior. You can configure the ObjectMapper and XmlMapper instances using the environment. Jackson provides an extensive suite of simple on/off features that can be used to configure various aspects of its processing. These features are described in six enums in Jackson which map onto properties in the environment: Jackson enum Environment property com.fasterxml.jackson.databind.DeserializationFeaturespring.jackson.deserialization.=true| false com.fasterxml.jackson.core.JsonGenerator.Featurespring.jackson.generator.=true| false com.fasterxml.jackson.databind.MapperFeaturespring.jackson.mapper.=true| false com.fasterxml.jackson.core.JsonParser.Featurespring.jackson.parser.=true| false com.fasterxml.jackson.databind.SerializationFeaturespring.jackson.serialization.=true| false com.fasterxml.jackson.annotation.JsonInclude.Includespring.jackson.serialization- inclusion=always|non_null| non_absent|non_default|non_empty For example, to enable pretty print, set spring.jackson.serialization.indent_output=true. Note that, thanks to the use of relaxed binding, the case of indent_output doesn’t have to match the case of the corresponding enum constant which is INDENT_OUTPUT. If you want to replace the default ObjectMapper completely, define a @Bean of that type and mark it as @Primary. Defining a @Bean of type Jackson2ObjectMapperBuilder will allow you to customize both default ObjectMapper and XmlMapper (used in MappingJackson2HttpMessageConverter and MappingJackson2XmlHttpMessageConverter respectively). Another way to customize Jackson is to add beans of type com.fasterxml.jackson.databind.Module to your context. They will be registered with every bean of type ObjectMapper, providing a global mechanism for contributing custom modules when you add new features to your application. Finally, if you provide any @Beans of type MappingJackson2HttpMessageConverter then they will replace the default value in the MVC configuration. Also, a convenience bean is provided of type HttpMessageConverters (always available if you use the default MVC configuration) which has some useful methods to access the default and user-enhanced message converters. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 230 See also the Section 73.4, “Customize the @ResponseBody rendering” section and the WebMvcAutoConfiguration source code for more details. 73.4 Customize the @ResponseBody rendering Spring uses HttpMessageConverters to render @ResponseBody (or responses from @RestController). You can contribute additional converters by simply adding beans of that type in a Spring Boot context. If a bean you add is of a type that would have been included by default anyway (like MappingJackson2HttpMessageConverter for JSON conversions) then it will replace the default value. A convenience bean is provided of type HttpMessageConverters (always available if you use the default MVC configuration) which has some useful methods to access the default and user- enhanced message converters (useful, for example if you want to manually inject them into a custom RestTemplate). As in normal MVC usage, any WebMvcConfigurerAdapter beans that you provide can also contribute converters by overriding the configureMessageConverters method, but unlike with normal MVC, you can supply only additional converters that you need (because Spring Boot uses the same mechanism to contribute its defaults). Finally, if you opt-out of the Spring Boot default MVC configuration by providing your own @EnableWebMvc configuration, then you can take control completely and do everything manually using getMessageConverters from WebMvcConfigurationSupport. See the WebMvcAutoConfiguration source code for more details. 73.5 Handling Multipart File Uploads Spring Boot embraces the Servlet 3 javax.servlet.http.Part API to support uploading files. By default Spring Boot configures Spring MVC with a maximum file of 1Mb per file and a maximum of 10Mb of file data in a single request. You may override these values, as well as the location to which intermediate data is stored (e.g., to the /tmp directory) and the threshold past which data is flushed to disk by using the properties exposed in the MultipartProperties class. If you want to specify that files be unlimited, for example, set the spring.http.multipart.max-file-size property to -1. The multipart support is helpful when you want to receive multipart encoded file data as a @RequestParam-annotated parameter of type MultipartFile in a Spring MVC controller handler method. See the MultipartAutoConfiguration source for more details. 73.6 Switch off the Spring MVC DispatcherServlet Spring Boot wants to serve all content from the root of your application / down. If you would rather map your own servlet to that URL you can do it, but of course you may lose some of the other Boot MVC features. To add your own servlet and map it to the root resource just declare a @Bean of type Servlet and give it the special bean name dispatcherServlet (You can also create a bean of a different type with that name if you want to switch it off and not replace it). 73.7 Switch off the Default MVC configuration The easiest way to take complete control over MVC configuration is to provide your own @Configuration with the @EnableWebMvc annotation. This will leave all MVC configuration in your hands. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 231 73.8 Customize ViewResolvers A ViewResolver is a core component of Spring MVC, translating view names in @Controller to actual View implementations. Note that ViewResolvers are mainly used in UI applications, rather than REST-style services (a View is not used to render a @ResponseBody). There are many implementations of ViewResolver to choose from, and Spring on its own is not opinionated about which ones you should use. Spring Boot, on the other hand, installs one or two for you depending on what it finds on the classpath and in the application context. The DispatcherServlet uses all the resolvers it finds in the application context, trying each one in turn until it gets a result, so if you are adding your own you have to be aware of the order and in which position your resolver is added. WebMvcAutoConfiguration adds the following ViewResolvers to your context: • An InternalResourceViewResolver with bean id ‘defaultViewResolver’. This one locates physical resources that can be rendered using the DefaultServlet (e.g. static resources and JSP pages if you are using those). It applies a prefix and a suffix to the view name and then looks for a physical resource with that path in the servlet context (defaults are both empty, but accessible for external configuration via spring.mvc.view.prefix and spring.mvc.view.suffix). It can be overridden by providing a bean of the same type. • A BeanNameViewResolver with id ‘beanNameViewResolver’. This is a useful member of the view resolver chain and will pick up any beans with the same name as the View being resolved. It shouldn’t be necessary to override or replace it. • A ContentNegotiatingViewResolver with id ‘viewResolver’ is only added if there are actually beans of type View present. This is a ‘master’ resolver, delegating to all the others and attempting to find a match to the ‘Accept’ HTTP header sent by the client. There is a useful blog about ContentNegotiatingViewResolver that you might like to study to learn more, and also look at the source code for detail. You can switch off the auto-configured ContentNegotiatingViewResolver by defining a bean named ‘viewResolver’. • If you use Thymeleaf you will also have a ThymeleafViewResolver with id ‘thymeleafViewResolver’. It looks for resources by surrounding the view name with a prefix and suffix (externalized to spring.thymeleaf.prefix and spring.thymeleaf.suffix, defaults ‘classpath:/templates/’ and ‘.html’ respectively). It can be overridden by providing a bean of the same name. • If you use FreeMarker you will also have a FreeMarkerViewResolver with id ‘freeMarkerViewResolver’. It looks for resources in a loader path (externalized to spring.freemarker.templateLoaderPath, default ‘classpath:/templates/’) by surrounding the view name with a prefix and suffix (externalized to spring.freemarker.prefix and spring.freemarker.suffix, with empty and ‘.ftl’ defaults respectively). It can be overridden by providing a bean of the same name. • If you use Groovy templates (actually if groovy-templates is on your classpath) you will also have a GroovyMarkupViewResolver with id ‘groovyMarkupViewResolver’. It looks for resources in a loader path by surrounding the view name with a prefix and suffix (externalized to spring.groovy.template.prefix and spring.groovy.template.suffix, defaults ‘classpath:/templates/’ and ‘.tpl’ respectively). It can be overridden by providing a bean of the same name. • If you use Velocity you will also have a VelocityViewResolver with id ‘velocityViewResolver’. It looks for resources in a loader path (externalized to spring.velocity.resourceLoaderPath, Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 232 default ‘classpath:/templates/’) by surrounding the view name with a prefix and suffix (externalized to spring.velocity.prefix and spring.velocity.suffix, with empty and ‘.vm’ defaults respectively). It can be overridden by providing a bean of the same name. Check out WebMvcAutoConfiguration, ThymeleafAutoConfiguration, FreeMarkerAutoConfiguration, GroovyTemplateAutoConfiguration and VelocityAutoConfiguration 73.9 Velocity By default, Spring Boot configures a VelocityViewResolver. If you need a VelocityLayoutViewResolver instead, you can easily configure your own by creating a bean with name velocityViewResolver. You can also inject the VelocityProperties instance to apply the base defaults to your custom view resolver. The following example replaces the auto-configured velocity view resolver with a VelocityLayoutViewResolver defining a customized layoutUrl and all settings that would have been applied from the auto-configuration: @Bean(name = "velocityViewResolver") public VelocityLayoutViewResolver velocityViewResolver(VelocityProperties properties) { VelocityLayoutViewResolver resolver = new VelocityLayoutViewResolver(); properties.applyToViewResolver(resolver); resolver.setLayoutUrl("layout/default.vm"); return resolver; } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 233 74. Logging Spring Boot has no mandatory logging dependency, except for the Commons Logging API, of which there are many implementations to choose from. To use Logback you need to include it and jcl-over- slf4j (which implements the Commons Logging API) on the classpath. The simplest way to do that is through the starters which all depend on spring-boot-starter-logging. For a web application you only need spring-boot-starter-web since it depends transitively on the logging starter. For example, using Maven: org.springframework.boot spring-boot-starter-web Spring Boot has a LoggingSystem abstraction that attempts to configure logging based on the content of the classpath. If Logback is available it is the first choice. If the only change you need to make to logging is to set the levels of various loggers then you can do that in application.properties using the "logging.level" prefix, e.g. logging.level.org.springframework.web=DEBUG logging.level.org.hibernate=ERROR You can also set the location of a file to log to (in addition to the console) using "logging.file". To configure the more fine-grained settings of a logging system you need to use the native configuration format supported by the LoggingSystem in question. By default Spring Boot picks up the native configuration from its default location for the system (e.g. classpath:logback.xml for Logback), but you can set the location of the config file using the "logging.config" property. 74.1 Configure Logback for logging If you put a logback.xml in the root of your classpath it will be picked up from there (or logback- spring.xml to take advantage of the templating features provided by Boot). Spring Boot provides a default base configuration that you can include if you just want to set levels, e.g. If you look at that base.xml in the spring-boot jar, you will see that it uses some useful System properties which the LoggingSystem takes care of creating for you. These are: • ${PID} the current process ID. • ${LOG_FILE} if logging.file was set in Boot’s external configuration. • ${LOG_PATH} if logging.path was set (representing a directory for log files to live in). • ${LOG_EXCEPTION_CONVERSION_WORD} if logging.exception-conversion-word was set in Boot’s external configuration. Spring Boot also provides some nice ANSI colour terminal output on a console (but not in a log file) using a custom Logback converter. See the default base.xml configuration for details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 234 If Groovy is on the classpath you should be able to configure Logback with logback.groovy as well (it will be given preference if present). Configure logback for file only output If you want to disable console logging and write output only to a file you need a custom logback- spring.xml that imports file-appender.xml but not console-appender.xml: You also need to add logging.file to your application.properties: logging.file=myapplication.log 74.2 Configure Log4j for logging Spring Boot supports Log4j 2 for logging configuration if it is on the classpath. If you are using the starters for assembling dependencies that means you have to exclude Logback and then include log4j 2 instead. If you aren’t using the starters then you need to provide jcl-over-slf4j (at least) in addition to Log4j 2. The simplest path is probably through the starters, even though it requires some jiggling with excludes, .e.g. in Maven: org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter org.springframework.boot spring-boot-starter-logging org.springframework.boot spring-boot-starter-log4j2 Note The use of the Log4j starters gathers together the dependencies for common logging requirements (e.g. including having Tomcat use java.util.logging but configuring the output using Log4j 2). See the Actuator Log4j 2 samples for more detail and to see it in action. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 235 Use YAML or JSON to configure Log4j 2 In addition to its default XML configuration format, Log4j 2 also supports YAML and JSON configuration files. To configure Log4j 2 to use an alternative configuration file format, add the appropriate dependencies to the classpath and name your configuration files to match your chosen file format: Format Dependencies File names YAML com.fasterxml.jackson.core:jackson-databind com.fasterxml.jackson.dataformat:jackson-dataformat- yaml log4j2.yaml log4j2.yml JSON com.fasterxml.jackson.core:jackson-databind log4j2.json log4j2.jsn Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 236 75. Data Access 75.1 Configure a DataSource To override the default settings just define a @Bean of your own of type DataSource. Spring Boot provides a utility builder class DataSourceBuilder that can be used to create one of the standard ones (if it is on the classpath), or you can just create your own, and bind it to a set of Environment properties as explained in the section called “Third-party configuration”, e.g. @Bean @ConfigurationProperties(prefix="datasource.mine") public DataSource dataSource() { return new FancyDataSource(); } datasource.mine.jdbcUrl=jdbc:h2:mem:mydb datasource.mine.user=sa datasource.mine.poolSize=30 See Section 29.1, “Configure a DataSource” in the ‘Spring Boot features’ section and the DataSourceAutoConfiguration class for more details. Tip You could also do that if you want to configure a JNDI data-source. @Bean(destroyMethod="") @ConfigurationProperties(prefix="datasource.mine") public DataSource dataSource() throws Exception { JndiDataSourceLookup dataSourceLookup = new JndiDataSourceLookup(); return dataSourceLookup.getDataSource("java:comp/env/jdbc/YourDS"); } 75.2 Configure Two DataSources Creating more than one data source works the same as creating the first one. You might want to mark one of them as @Primary if you are using the default auto-configuration for JDBC or JPA (then that one will be picked up by any @Autowired injections). @Bean @Primary @ConfigurationProperties(prefix="datasource.primary") public DataSource primaryDataSource() { return DataSourceBuilder.create().build(); } @Bean @ConfigurationProperties(prefix="datasource.secondary") public DataSource secondaryDataSource() { return DataSourceBuilder.create().build(); } 75.3 Use Spring Data repositories Spring Data can create implementations for you of @Repository interfaces of various flavors. Spring Boot will handle all of that for you as long as those @Repositories are included in the same package (or a sub-package) of your @EnableAutoConfiguration class. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 237 For many applications all you will need is to put the right Spring Data dependencies on your classpath (there is a spring-boot-starter-data-jpa for JPA and a spring-boot-starter-data- mongodb for Mongodb), create some repository interfaces to handle your @Entity objects. Examples are in the JPA sample or the Mongodb sample. Spring Boot tries to guess the location of your @Repository definitions, based on the @EnableAutoConfiguration it finds. To get more control, use the @EnableJpaRepositories annotation (from Spring Data JPA). 75.4 Separate @Entity definitions from Spring configuration Spring Boot tries to guess the location of your @Entity definitions, based on the @EnableAutoConfiguration it finds. To get more control, you can use the @EntityScan annotation, e.g. @Configuration @EnableAutoConfiguration @EntityScan(basePackageClasses=City.class) public class Application { //... } 75.5 Configure JPA properties Spring Data JPA already provides some vendor-independent configuration options (e.g. for SQL logging) and Spring Boot exposes those, and a few more for hibernate as external configuration properties. The most common options to set are: spring.jpa.hibernate.ddl-auto=create-drop spring.jpa.hibernate.naming.physical-strategy=com.example.MyPhysicalNamingStrategy spring.jpa.database=H2 spring.jpa.show-sql=true The ddl-auto setting is a special case in that it has different defaults depending on whether you are using an embedded database (create-drop) or not (none). In addition all properties in spring.jpa.properties.* are passed through as normal JPA properties (with the prefix stripped) when the local EntityManagerFactory is created. Spring Boot provides a consistent naming strategy regardless of the Hibernate generation that you are using. If you are using Hibernate 4, you can customize it using spring.jpa.hibernate.naming.strategy; Hibernate 5 defines a Physical and Implicit naming strategies: Spring Boot configures SpringPhysicalNamingStrategy by default. This implementation provides the same table structure as Hibernate 4. If you’d rather use Hibernate 5’s default instead, set the following property: spring.jpa.hibernate.naming.physical- strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl See HibernateJpaAutoConfiguration and JpaBaseConfiguration for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 238 75.6 Use a custom EntityManagerFactory To take full control of the configuration of the EntityManagerFactory, you need to add a @Bean named ‘entityManagerFactory’. Spring Boot auto-configuration switches off its entity manager based on the presence of a bean of that type. 75.7 Use Two EntityManagers Even if the default EntityManagerFactory works fine, you will need to define a new one because otherwise the presence of the second bean of that type will switch off the default. To make it easy to do that you can use the convenient EntityManagerBuilder provided by Spring Boot, or if you prefer you can just use the LocalContainerEntityManagerFactoryBean directly from Spring ORM. Example: // add two data sources configured as above @Bean public LocalContainerEntityManagerFactoryBean customerEntityManagerFactory( EntityManagerFactoryBuilder builder) { return builder .dataSource(customerDataSource()) .packages(Customer.class) .persistenceUnit("customers") .build(); } @Bean public LocalContainerEntityManagerFactoryBean orderEntityManagerFactory( EntityManagerFactoryBuilder builder) { return builder .dataSource(orderDataSource()) .packages(Order.class) .persistenceUnit("orders") .build(); } The configuration above almost works on its own. To complete the picture you need to configure TransactionManagers for the two EntityManagers as well. One of them could be picked up by the default JpaTransactionManager in Spring Boot if you mark it as @Primary. The other would have to be explicitly injected into a new instance. Or you might be able to use a JTA transaction manager spanning both. If you are using Spring Data, you need to configure @EnableJpaRepositories accordingly: @Configuration @EnableJpaRepositories(basePackageClasses = Customer.class, entityManagerFactoryRef = "customerEntityManagerFactory") public class CustomerConfiguration { ... } @Configuration @EnableJpaRepositories(basePackageClasses = Order.class, entityManagerFactoryRef = "orderEntityManagerFactory") public class OrderConfiguration { ... } Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 239 75.8 Use a traditional persistence.xml Spring doesn’t require the use of XML to configure the JPA provider, and Spring Boot assumes you want to take advantage of that feature. If you prefer to use persistence.xml then you need to define your own @Bean of type LocalEntityManagerFactoryBean (with id ‘entityManagerFactory’, and set the persistence unit name there. See JpaBaseConfiguration for the default settings. 75.9 Use Spring Data JPA and Mongo repositories Spring Data JPA and Spring Data Mongo can both create Repository implementations for you automatically. If they are both present on the classpath, you might have to do some extra configuration to tell Spring Boot which one (or both) you want to create repositories for you. The most explicit way to do that is to use the standard Spring Data @Enable*Repositories and tell it the location of your Repository interfaces (where ‘*’ is ‘Jpa’ or ‘Mongo’ or both). There are also flags spring.data.*.repositories.enabled that you can use to switch the auto- configured repositories on and off in external configuration. This is useful for instance in case you want to switch off the Mongo repositories and still use the auto-configured MongoTemplate. The same obstacle and the same features exist for other auto-configured Spring Data repository types (Elasticsearch, Solr). Just change the names of the annotations and flags respectively. 75.10 Expose Spring Data repositories as REST endpoint Spring Data REST can expose the Repository implementations as REST endpoints for you as long as Spring MVC has been enabled for the application. Spring Boot exposes as set of useful properties from the spring.data.rest namespace that customize the RepositoryRestConfiguration. If you need to provide additional customization, you should use a RepositoryRestConfigurer bean. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 240 76. Database initialization An SQL database can be initialized in different ways depending on what your stack is. Or of course you can do it manually as long as the database is a separate process. 76.1 Initialize a database using JPA JPA has features for DDL generation, and these can be set up to run on startup against the database. This is controlled through two external properties: • spring.jpa.generate-ddl (boolean) switches the feature on and off and is vendor independent. • spring.jpa.hibernate.ddl-auto (enum) is a Hibernate feature that controls the behavior in a more fine-grained way. See below for more detail. 76.2 Initialize a database using Hibernate You can set spring.jpa.hibernate.ddl-auto explicitly and the standard Hibernate property values are none, validate, update, create, create-drop. Spring Boot chooses a default value for you based on whether it thinks your database is embedded (default create-drop) or not (default none). An embedded database is detected by looking at the Connection type: hsqldb, h2 and derby are embedded, the rest are not. Be careful when switching from in-memory to a ‘real’ database that you don’t make assumptions about the existence of the tables and data in the new platform. You either have to set ddl-auto explicitly, or use one of the other mechanisms to initialize the database. Note You can output the schema creation by enabling the org.hibernate.SQL logger. This is done for you automatically if you enable the debug mode. In addition, a file named import.sql in the root of the classpath will be executed on startup. This can be useful for demos and for testing if you are careful, but probably not something you want to be on the classpath in production. It is a Hibernate feature (nothing to do with Spring). 76.3 Initialize a database using Spring JDBC Spring JDBC has a DataSource initializer feature. Spring Boot enables it by default and loads SQL from the standard locations schema.sql and data.sql (in the root of the classpath). In addition Spring Boot will load the schema-${platform}.sql and data-${platform}.sql files (if present), where platform is the value of spring.datasource.platform, e.g. you might choose to set it to the vendor name of the database (hsqldb, h2, oracle, mysql, postgresql etc.). Spring Boot enables the fail-fast feature of the Spring JDBC initializer by default, so if the scripts cause exceptions the application will fail to start. The script locations can be changed by setting spring.datasource.schema and spring.datasource.data, and neither location will be processed if spring.datasource.initialize=false. To disable the fail-fast you can set spring.datasource.continue-on-error=true. This can be useful once an application has matured and been deployed a few times, since the scripts can act as ‘poor man’s migrations’ — inserts that fail mean that the data is already there, so there would be no need to prevent the application from running, for instance. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 241 If you want to use the schema.sql initialization in a JPA app (with Hibernate) then ddl- auto=create-drop will lead to errors if Hibernate tries to create the same tables. To avoid those errors set ddl-auto explicitly to "" (preferable) or "none". Whether or not you use ddl-auto=create- drop you can always use data.sql to initialize new data. 76.4 Initialize a Spring Batch database If you are using Spring Batch then it comes pre-packaged with SQL initialization scripts for most popular database platforms. Spring Boot will detect your database type, and execute those scripts by default, and in this case will switch the fail fast setting to false (errors are logged but do not prevent the application from starting). This is because the scripts are known to be reliable and generally do not contain bugs, so errors are ignorable, and ignoring them makes the scripts idempotent. You can switch off the initialization explicitly using spring.batch.initializer.enabled=false. 76.5 Use a higher-level database migration tool Spring Boot supports two higher-level migration tools: Flyway and Liquibase. Execute Flyway database migrations on startup To automatically run Flyway database migrations on startup, add the org.flywaydb:flyway-core to your classpath. The migrations are scripts in the form V__.sql (with an underscore- separated version, e.g. ‘1’ or ‘2_1’). By default they live in a folder classpath:db/migration but you can modify that using flyway.locations (a list). See the Flyway class from flyway-core for details of available settings like schemas etc. In addition Spring Boot provides a small set of properties in FlywayProperties that can be used to disable the migrations, or switch off the location checking. Spring Boot will call Flyway.migrate() to perform the database migration. If you would like more control, provide a @Bean that implements FlywayMigrationStrategy. Tip If you want to make use of Flyway callbacks, those scripts should also live in the classpath:db/ migration folder. By default Flyway will autowire the (@Primary) DataSource in your context and use that for migrations. If you like to use a different DataSource you can create one and mark its @Bean as @FlywayDataSource - if you do that remember to create another one and mark it as @Primary if you want two data sources. Or you can use Flyway’s native DataSource by setting flyway. [url,user,password] in external properties. There is a Flyway sample so you can see how to set things up. Execute Liquibase database migrations on startup To automatically run Liquibase database migrations on startup, add the org.liquibase:liquibase-core to your classpath. The master change log is by default read from db/changelog/db.changelog-master.yaml but can be set using liquibase.change-log. In addition to YAML, Liquibase also supports JSON, XML, and SQL change log formats. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 242 See LiquibaseProperties for details of available settings like contexts, default schema etc. There is a Liquibase sample so you can see how to set things up. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 243 77. Batch applications 77.1 Execute Spring Batch jobs on startup Spring Batch auto-configuration is enabled by adding @EnableBatchProcessing (from Spring Batch) somewhere in your context. By default it executes all Jobs in the application context on startup (see JobLauncherCommandLineRunner for details). You can narrow down to a specific job or jobs by specifying spring.batch.job.names (comma-separated job name patterns). If the application context includes a JobRegistry then the jobs in spring.batch.job.names are looked up in the registry instead of being autowired from the context. This is a common pattern with more complex systems where multiple jobs are defined in child contexts and registered centrally. See BatchAutoConfiguration and @EnableBatchProcessing for more details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 244 78. Actuator 78.1 Change the HTTP port or address of the actuator endpoints In a standalone application the Actuator HTTP port defaults to the same as the main HTTP port. To make the application listen on a different port set the external property management.port. To listen on a completely different network address (e.g. if you have an internal network for management and an external one for user applications) you can also set management.address to a valid IP address that the server is able to bind to. For more detail look at the ManagementServerProperties source code and Section 48.3, “Customizing the management server port” in the ‘Production-ready features’ section. 78.2 Customize the ‘whitelabel’ error page Spring Boot installs a ‘whitelabel’ error page that you will see in browser client if you encounter a server error (machine clients consuming JSON and other media types should see a sensible response with the right error code). Note Set server.error.whitelabel.enabled=false to switch the default error page off which will restore the default of the servlet container that you are using. Note that Spring Boot will still attempt to resolve the error view so you’d probably add you own error page rather than disabling it completely. Overriding the error page with your own depends on the templating technology that you are using. For example, if you are using Thymeleaf you would add an error.html template and if you are using FreeMarker you would add an error.ftl template. In general what you need is a View that resolves with a name of error, and/or a @Controller that handles the /error path. Unless you replaced some of the default configuration you should find a BeanNameViewResolver in your ApplicationContext so a @Bean with id error would be a simple way of doing that. Look at ErrorMvcAutoConfiguration for more options. See also the section on Error Handling for details of how to register handlers in the servlet container. 78.3 Actuator and Jersey Actuator HTTP endpoints are only available for Spring MVC-based applications. If you want to use Jersey and still use the actuator you will need to enable Spring MVC (by depending on spring- boot-starter-web, for example). By default, both Jersey and the Spring MVC dispatcher servlet are mapped to the same path (/). You will need to change the path for one of them (by configuring server.servlet-path for Spring MVC or spring.jersey.application-path for Jersey). For example, if you add server.servlet-path=/system into application.properties, the actuator HTTP endpoints will be available under /system. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 245 79. Security 79.1 Switch off the Spring Boot security configuration If you define a @Configuration with @EnableWebSecurity anywhere in your application it will switch off the default webapp security settings in Spring Boot. To tweak the defaults try setting properties in security.* (see SecurityProperties for details of available settings) and SECURITY section of Common application properties. 79.2 Change the AuthenticationManager and add user accounts If you provide a @Bean of type AuthenticationManager the default one will not be created, so you have the full feature set of Spring Security available (e.g. various authentication options). Spring Security also provides a convenient AuthenticationManagerBuilder which can be used to build an AuthenticationManager with common options. The recommended way to use this in a webapp is to inject it into a void method in a WebSecurityConfigurerAdapter, e.g. @Configuration public class SecurityConfiguration extends WebSecurityConfigurerAdapter { @Autowired public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception { auth.inMemoryAuthentication() .withUser("barry").password("password").roles("USER"); // ... etc. } // ... other stuff for application security } You will get the best results if you put this in a nested class, or a standalone class (i.e. not mixed in with a lot of other @Beans that might be allowed to influence the order of instantiation). The secure web sample is a useful template to follow. If you experience instantiation issues (e.g. using JDBC or JPA for the user detail store) it might be worth extracting the AuthenticationManagerBuilder callback into a GlobalAuthenticationConfigurerAdapter (in the init() method so it happens before the authentication manager is needed elsewhere), e.g. @Configuration public class AuthenticationManagerConfiguration extends GlobalAuthenticationConfigurerAdapter { @Override public void init(AuthenticationManagerBuilder auth) { auth.inMemoryAuthentication() // ... etc. } } 79.3 Enable HTTPS when running behind a proxy server Ensuring that all your main endpoints are only available over HTTPS is an important chore for any application. If you are using Tomcat as a servlet container, then Spring Boot will add Tomcat’s own Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 246 RemoteIpValve automatically if it detects some environment settings, and you should be able to rely on the HttpServletRequest to report whether it is secure or not (even downstream of a proxy server that handles the real SSL termination). The standard behavior is determined by the presence or absence of certain request headers (x-forwarded-for and x-forwarded-proto), whose names are conventional, so it should work with most front end proxies. You can switch on the valve by adding some entries to application.properties, e.g. server.tomcat.remote_ip_header=x-forwarded-for server.tomcat.protocol_header=x-forwarded-proto (The presence of either of those properties will switch on the valve. Or you can add the RemoteIpValve yourself by adding a TomcatEmbeddedServletContainerFactory bean.) Spring Security can also be configured to require a secure channel for all (or some requests). To switch that on in a Spring Boot application you just need to set security.require_ssl to true in application.properties. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 247 80. Hot swapping 80.1 Reload static content There are several options for hot reloading. The recommended approach is to use spring-boot- devtools as it provides additional development-time features such as support for fast application restarts and LiveReload as well as sensible development-time configuration (e.g. template caching). Alternatively, running in an IDE (especially with debugging on) is a good way to do development (all modern IDEs allow reloading of static resources and usually also hot-swapping of Java class changes). Finally, the Maven and Gradle plugins can be configured (see the addResources property) to support running from the command line with reloading of static files. You can use that with an external css/js compiler process if you are writing that code with higher level tools. 80.2 Reload templates without restarting the container Most of the templating technologies supported by Spring Boot include a configuration option to disable caching (see below for details). If you’re using the spring-boot-devtools module these properties will be automatically configured for you at development time. Thymeleaf templates If you are using Thymeleaf, then set spring.thymeleaf.cache to false. See ThymeleafAutoConfiguration for other Thymeleaf customization options. FreeMarker templates If you are using FreeMarker, then set spring.freemarker.cache to false. See FreeMarkerAutoConfiguration for other FreeMarker customization options. Groovy templates If you are using Groovy templates, then set spring.groovy.template.cache to false. See GroovyTemplateAutoConfiguration for other Groovy customization options. Velocity templates If you are using Velocity, then set spring.velocity.cache to false. See VelocityAutoConfiguration for other Velocity customization options. 80.3 Fast application restarts The spring-boot-devtools module includes support for automatic application restarts. Whilst not as fast a technologies such as JRebel or Spring Loaded it’s usually significantly faster than a “cold start”. You should probably give it a try before investigating some of the more complex reload options discussed below. For more details see the Chapter 20, Developer tools section. 80.4 Reload Java classes without restarting the container Modern IDEs (Eclipse, IDEA, etc.) all support hot swapping of bytecode, so if you make a change that doesn’t affect class or method signatures it should reload cleanly with no side effects. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 248 Spring Loaded goes a little further in that it can reload class definitions with changes in the method signatures. With some customization it can force an ApplicationContext to refresh itself (but there is no general mechanism to ensure that would be safe for a running application anyway, so it would only ever be a development time trick probably). Configuring Spring Loaded for use with Maven To use Spring Loaded with the Maven command line, just add it as a dependency in the Spring Boot plugin declaration, e.g. org.springframework.boot spring-boot-maven-plugin org.springframework springloaded 1.2.0.RELEASE This normally works pretty well with Eclipse and IntelliJ IDEA as long as they have their build configuration aligned with the Maven defaults (Eclipse m2e does this out of the box). Configuring Spring Loaded for use with Gradle and IntelliJ IDEA You need to jump through a few hoops if you want to use Spring Loaded in combination with Gradle and IntelliJ IDEA. By default, IntelliJ IDEA will compile classes into a different location than Gradle, causing Spring Loaded monitoring to fail. To configure IntelliJ IDEA correctly you can use the idea Gradle plugin: buildscript { repositories { jcenter() } dependencies { classpath "org.springframework.boot:spring-boot-gradle-plugin:1.4.0.BUILD-SNAPSHOT" classpath 'org.springframework:springloaded:1.2.0.RELEASE' } } apply plugin: 'idea' idea { module { inheritOutputDirs = false outputDir = file("$buildDir/classes/main/") } } // ... Note IntelliJ IDEA must be configured to use the same Java version as the command line Gradle task and springloaded must be included as a buildscript dependency. You can also additionally enable ‘Make Project Automatically’ inside IntelliJ IDEA to automatically compile your code whenever a file is saved. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 249 81. Build 81.1 Generate build information Both the Maven and Gradle plugin allow to generate build information containing the coordinates, name and version of the project. The plugin can also be configured to add additional properties through configuration. When such file is present, Spring Boot auto-configures a BuildProperties bean. To generate build information with Maven, add an execution for the build-info goal: org.springframework.boot spring-boot-maven-plugin 1.4.0.BUILD-SNAPSHOT build-info Tip Check the Spring Boot Maven Plugin documentation for more details. And to do the same with Gradle: springBoot { buildInfo() } Additional properties can be added using the DSL: springBoot { buildInfo { additionalProperties = [ 'foo': 'bar' ] } } 81.2 Generate git information Both Maven and Gradle allow to generate a git.properties file containing information about the state of your git source code repository when the project was built. For Maven users the spring-boot-starter-parent POM includes a pre-configured plugin to generate a git.properties file. Simply add the following declaration to your POM: pl.project13.maven git-commit-id-plugin Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 250 Gradle users can achieve the same result using the gradle-git-properties plugin plugins { id "com.gorylenko.gradle-git-properties" version "1.4.6" } 81.3 Customize dependency versions If you use a Maven build that inherits directly or indirectly from spring-boot-dependencies (for instance spring-boot-starter-parent) but you want to override a specific third-party dependency you can add appropriate elements. Browse the spring-boot-dependencies POM for a complete list of properties. For example, to pick a different slf4j version you would add the following: 1.7.5 Note This only works if your Maven project inherits (directly or indirectly) from spring- boot-dependencies. If you have added spring-boot-dependencies in your own dependencyManagement section with import you have to redefine the artifact yourself instead of overriding the property. Warning Each Spring Boot release is designed and tested against a specific set of third-party dependencies. Overriding versions may cause compatibility issues. To override dependency versions in Gradle, you can specify a version as shown below: ext['slf4j.version'] = '1.7.5' For additional information, please refer to the Gradle Dependency Management Plugin documentation. 81.4 Create an executable JAR with Maven The spring-boot-maven-plugin can be used to create an executable ‘fat’ JAR. If you are using the spring-boot-starter-parent POM you can simply declare the plugin and your jars will be repackaged: org.springframework.boot spring-boot-maven-plugin If you are not using the parent POM you can still use the plugin, however, you must additionally add an section: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 251 org.springframework.boot spring-boot-maven-plugin 1.4.0.BUILD-SNAPSHOT repackage See the plugin documentation for full usage details. 81.5 Create an additional executable JAR If you want to use your project as a library jar for other projects to depend on, and in addition have an executable (e.g. demo) version of it, you will want to configure the build in a slightly different way. For Maven the normal JAR plugin and the Spring Boot plugin both have a ‘classifier’ configuration that you can add to create an additional JAR. Example (using the Spring Boot Starter Parent to manage the plugin versions and other configuration defaults): org.springframework.boot spring-boot-maven-plugin exec Two jars are produced, the default one, and an executable one using the Boot plugin with classifier ‘exec’. For Gradle users the steps are similar. Example: bootRepackage { classifier = 'exec' } 81.6 Extract specific libraries when an executable jar runs Most nested libraries in an executable jar do not need to be unpacked in order to run, however, certain libraries can have problems. For example, JRuby includes its own nested jar support which assumes that the jruby-complete.jar is always directly available as a file in its own right. To deal with any problematic libraries, you can flag that specific nested jars should be automatically unpacked to the ‘temp folder’ when the executable jar first runs. For example, to indicate that JRuby should be flagged for unpack using the Maven Plugin you would add the following configuration: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 252 org.springframework.boot spring-boot-maven-plugin org.jruby jruby-complete And to do that same with Gradle: springBoot { requiresUnpack = ['org.jruby:jruby-complete'] } 81.7 Create a non-executable JAR with exclusions Often if you have an executable and a non-executable jar as build products, the executable version will have additional configuration files that are not needed in a library jar. E.g. the application.yml configuration file might excluded from the non-executable JAR. Here’s how to do that in Maven: org.springframework.boot spring-boot-maven-plugin exec maven-jar-plugin exec package jar exec package jar true application.yml Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 253 In Gradle you can create a new JAR archive with standard task DSL features, and then have the bootRepackage task depend on that one using its withJarTask property: jar { baseName = 'spring-boot-sample-profile' version = '0.0.0' excludes = ['**/application.yml'] } task('execJar', type:Jar, dependsOn: 'jar') { baseName = 'spring-boot-sample-profile' version = '0.0.0' classifier = 'exec' from sourceSets.main.output } bootRepackage { withJarTask = tasks['execJar'] } 81.8 Remote debug a Spring Boot application started with Maven To attach a remote debugger to a Spring Boot application started with Maven you can use the jvmArguments property of the maven plugin. Check this example for more details. 81.9 Remote debug a Spring Boot application started with Gradle To attach a remote debugger to a Spring Boot application started with Gradle you can use the applicationDefaultJvmArgs in build.gradle or --debug-jvm command line option. build.gradle: applicationDefaultJvmArgs = [ "-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005" ] Command line: $ gradle run --debug-jvm Check Gradle Application Plugin for more details. 81.10 Build an executable archive from Ant without using spring-boot-antlib To build with Ant you need to grab dependencies, compile and then create a jar or war archive. To make it executable you can either use the spring-boot-antlib module, or you can follow these instructions: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 254 1. If you are building a jar, package the application’s classes and resources in a nested BOOT-INF/ classes directory. If you are building a war, package the application’s classes in a nested WEB- INF/classes directory as usual. 2. Add the runtime dependencies in a nested BOOT-INF/lib directory for a jar or WEB-INF/lib for a war. Remember not to compress the entries in the archive. 3. Add the provided (embedded container) dependencies in a nested BOOT-INF/lib directory for jar or WEB-INF/lib-provided for a war. Remember not to compress the entries in the archive. 4. Add the spring-boot-loader classes at the root of the archive (so the Main-Class is available). 5. Use the appropriate launcher, e.g. JarLauncher for a jar file, as a Main-Class attribute in the manifest and specify the other properties it needs as manifest entries, principally a Start-Class. Example: The Ant Sample has a build.xml with a manual task that should work if you run it with $ ant -lib clean manual after which you can run the application with $ java -jar target/*.jar 81.11 How to use Java 6 If you want to use Spring Boot with Java 6 there are a small number of configuration changes that you will have to make. The exact changes depend on your application’s functionality. Embedded servlet container compatibility If you are using one of Boot’s embedded Servlet containers you will have to use a Java 6-compatible container. Both Tomcat 7 and Jetty 8 are Java 6 compatible. See Section 72.15, “Use Tomcat 7” and Section 72.16, “Use Jetty 8” for details. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 255 JTA API compatibility While the Java Transaction API itself doesn’t require Java 7 the official API jar contains classes that have been built to require Java 7. If you are using JTA then you will need to replace the official JTA 1.2 API jar with one that has been built to work on Java 6. To do so, exclude any transitive dependencies on javax.transaction:javax.transaction-api and replace them with a dependency on org.jboss.spec.javax.transaction:jboss-transaction-api_1.2_spec:1.0.0.Final Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 256 82. Traditional deployment 82.1 Create a deployable war file The first step in producing a deployable war file is to provide a SpringBootServletInitializer subclass and override its configure method. This makes use of Spring Framework’s Servlet 3.0 support and allows you to configure your application when it’s launched by the servlet container. Typically, you update your application’s main class to extend SpringBootServletInitializer: @SpringBootApplication public class Application extends SpringBootServletInitializer { @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { return application.sources(Application.class); } public static void main(String[] args) throws Exception { SpringApplication.run(Application.class, args); } } The next step is to update your build configuration so that your project produces a war file rather than a jar file. If you’re using Maven and using spring-boot-starter-parent (which configures Maven’s war plugin for you) all you need to do is modify pom.xml to change the packaging to war: war If you’re using Gradle, you need to modify build.gradle to apply the war plugin to the project: apply plugin: 'war' The final step in the process is to ensure that the embedded servlet container doesn’t interfere with the servlet container to which the war file will be deployed. To do so, you need to mark the embedded servlet container dependency as provided. If you’re using Maven: org.springframework.boot spring-boot-starter-tomcat provided And if you’re using Gradle: dependencies { // … providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat' // … } If you’re using the Spring Boot build tools, marking the embedded servlet container dependency as provided will produce an executable war file with the provided dependencies packaged in a lib- Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 257 provided directory. This means that, in addition to being deployable to a servlet container, you can also run your application using java -jar on the command line. Tip Take a look at Spring Boot’s sample applications for a Maven-based example of the above- described configuration. 82.2 Create a deployable war file for older servlet containers Older Servlet containers don’t have support for the ServletContextInitializer bootstrap process used in Servlet 3.0. You can still use Spring and Spring Boot in these containers but you are going to need to add a web.xml to your application and configure it to load an ApplicationContext via a DispatcherServlet. 82.3 Convert an existing application to Spring Boot For a non-web application it should be easy (throw away the code that creates your ApplicationContext and replace it with calls to SpringApplication or SpringApplicationBuilder). Spring MVC web applications are generally amenable to first creating a deployable war application, and then migrating it later to an executable war and/or jar. Useful reading is in the Getting Started Guide on Converting a jar to a war. Create a deployable war by extending SpringBootServletInitializer (e.g. in a class called Application), and add the Spring Boot @EnableAutoConfiguration annotation. Example: @Configuration @EnableAutoConfiguration @ComponentScan public class Application extends SpringBootServletInitializer { @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { // Customize the application or call application.sources(...) to add sources // Since our example is itself a @Configuration class we actually don't // need to override this method. return application; } } Remember that whatever you put in the sources is just a Spring ApplicationContext and normally anything that already works should work here. There might be some beans you can remove later and let Spring Boot provide its own defaults for them, but it should be possible to get something working first. Static resources can be moved to /public (or /static or /resources or /META-INF/resources) in the classpath root. Same for messages.properties (Spring Boot detects this automatically in the root of the classpath). Vanilla usage of Spring DispatcherServlet and Spring Security should require no further changes. If you have other features in your application, using other servlets or filters for instance, then you may need to add some configuration to your Application context, replacing those elements from the web.xml as follows: • A @Bean of type Servlet or ServletRegistrationBean installs that bean in the container as if it was a and in web.xml. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 258 • A @Bean of type Filter or FilterRegistrationBean behaves similarly (like a and . • An ApplicationContext in an XML file can be added to an @Import in your Application. Or simple cases where annotation configuration is heavily used already can be recreated in a few lines as @Bean definitions. Once the war is working we make it executable by adding a main method to our Application, e.g. public static void main(String[] args) { SpringApplication.run(Application.class, args); } Applications can fall into more than one category: • Servlet 3.0+ applications with no web.xml. • Applications with a web.xml. • Applications with a context hierarchy. • Applications without a context hierarchy. All of these should be amenable to translation, but each might require slightly different tricks. Servlet 3.0+ applications might translate pretty easily if they already use the Spring Servlet 3.0+ initializer support classes. Normally all the code from an existing WebApplicationInitializer can be moved into a SpringBootServletInitializer. If your existing application has more than one ApplicationContext (e.g. if it uses AbstractDispatcherServletInitializer) then you might be able to squash all your context sources into a single SpringApplication. The main complication you might encounter is if that doesn’t work and you need to maintain the context hierarchy. See the entry on building a hierarchy for examples. An existing parent context that contains web-specific features will usually need to be broken up so that all the ServletContextAware components are in the child context. Applications that are not already Spring applications might be convertible to a Spring Boot application, and the guidance above might help, but your mileage may vary. 82.4 Deploying a WAR to WebLogic To deploy a Spring Boot application to WebLogic you must ensure that your servlet initializer directly implements WebApplicationInitializer (even if you extend from a base class that already implements it). A typical initializer for WebLogic would be something like this: import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.context.web.SpringBootServletInitializer; import org.springframework.web.WebApplicationInitializer; @SpringBootApplication public class MyApplication extends SpringBootServletInitializer implements WebApplicationInitializer { } If you use logback, you will also need to tell WebLogic to prefer the packaged version rather than the version that pre-installed with the server. You can do this by adding a WEB-INF/weblogic.xml file with the following contents: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 259 org.slf4j 82.5 Deploying a WAR in an Old (Servlet 2.5) Container Spring Boot uses Servlet 3.0 APIs to initialize the ServletContext (register Servlets etc.) so you can’t use the same application out of the box in a Servlet 2.5 container. It is however possible to run a Spring Boot application on an older container with some special tools. If you include org.springframework.boot:spring-boot-legacy as a dependency (maintained separately to the core of Spring Boot and currently available at 1.0.0.RELEASE), all you should need to do is create a web.xml and declare a context listener to create the application context and your filters and servlets. The context listener is a special purpose one for Spring Boot, but the rest of it is normal for a Spring application in Servlet 2.5. Example: contextConfigLocation demo.Application org.springframework.boot.legacy.context.web.SpringBootContextLoaderListener metricFilter org.springframework.web.filter.DelegatingFilterProxy metricFilter /* appServlet org.springframework.web.servlet.DispatcherServlet contextAttribute org.springframework.web.context.WebApplicationContext.ROOT 1 appServlet / Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 260 In this example we are using a single application context (the one created by the context listener) and attaching it to the DispatcherServlet using an init parameter. This is normal in a Spring Boot application (you normally only have one application context). Part X. Appendices Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 262 Appendix A. Common application properties Various properties can be specified inside your application.properties/application.yml file or as command line switches. This section provides a list common Spring Boot properties and references to the underlying classes that consume them. Note Property contributions can come from additional jar files on your classpath so you should not consider this an exhaustive list. It is also perfectly legit to define your own properties. Warning This sample file is meant as a guide only. Do not copy/paste the entire content into your application; rather pick only the properties that you need. # =================================================================== # COMMON SPRING BOOT PROPERTIES # # This sample file is provided as a guideline. Do NOT copy it in its # entirety to your own application. ^^^ # =================================================================== # ---------------------------------------- # CORE PROPERTIES # ---------------------------------------- # BANNER banner.charset=UTF-8 # Banner file encoding. banner.location=classpath:banner.txt # Banner file location. banner.image.location=classpath:banner.gif # Banner image file location (jpg/png can also be used). banner.image.width= # Width of the banner image in chars (default 76) banner.image.height= # Height of the banner image in chars (default based on image height) banner.image.margin= # Left hand image margin in chars (default 2) banner.image.invert= # If images should be inverted for dark terminal themes (default false) # LOGGING logging.config= # Location of the logging configuration file. For instance `classpath:logback.xml` for Logback logging.exception-conversion-word=%wEx # Conversion word used when logging exceptions. logging.file= # Log file name. For instance `myapp.log` logging.level.*= # Log levels severity mapping. For instance `logging.level.org.springframework=DEBUG` logging.path= # Location of the log file. For instance `/var/log` logging.pattern.console= # Appender pattern for output to the console. Only supported with the default logback setup. logging.pattern.file= # Appender pattern for output to the file. Only supported with the default logback setup. logging.pattern.level= # Appender pattern for log level (default %5p). Only supported with the default logback setup. logging.register-shutdown-hook=false # Register a shutdown hook for the logging system when it is initialized. # AOP spring.aop.auto=true # Add @EnableAspectJAutoProxy. spring.aop.proxy-target-class=false # Whether subclass-based (CGLIB) proxies are to be created (true) as opposed to standard Java interface-based proxies (false). # IDENTITY (ContextIdApplicationContextInitializer) spring.application.index= # Application index. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 263 spring.application.name= # Application name. # ADMIN (SpringApplicationAdminJmxAutoConfiguration) spring.application.admin.enabled=false # Enable admin features for the application. spring.application.admin.jmx-name=org.springframework.boot:type=Admin,name=SpringApplication # JMX name of the application admin MBean. # AUTO-CONFIGURATION spring.autoconfigure.exclude= # Auto-configuration classes to exclude. # SPRING CORE spring.beaninfo.ignore=true # Skip search of BeanInfo classes. # SPRING CACHE (CacheProperties) spring.cache.cache-names= # Comma-separated list of cache names to create if supported by the underlying cache manager. spring.cache.caffeine.spec= # The spec to use to create caches. Check CaffeineSpec for more details on the spec format. spring.cache.couchbase.expiration=0 # Entry expiration in milliseconds. By default the entries never expire. spring.cache.ehcache.config= # The location of the configuration file to use to initialize EhCache. spring.cache.guava.spec= # The spec to use to create caches. Check CacheBuilderSpec for more details on the spec format. spring.cache.hazelcast.config= # The location of the configuration file to use to initialize Hazelcast. spring.cache.infinispan.config= # The location of the configuration file to use to initialize Infinispan. spring.cache.jcache.config= # The location of the configuration file to use to initialize the cache manager. spring.cache.jcache.provider= # Fully qualified name of the CachingProvider implementation to use to retrieve the JSR-107 compliant cache manager. Only needed if more than one JSR-107 implementation is available on the classpath. spring.cache.type= # Cache type, auto-detected according to the environment by default. # SPRING CONFIG - using environment property only (ConfigFileApplicationListener) spring.config.location= # Config file locations. spring.config.name=application # Config file name. # HAZELCAST (HazelcastProperties) spring.hazelcast.config= # The location of the configuration file to use to initialize Hazelcast. # PROJECT INFORMATION (ProjectInfoProperties) spring.info.build.location=classpath:META-INF/build-info.properties # Location of the generated build- info.properties file. spring.info.git.location=classpath:git.properties # Location of the generated git.properties file. # JMX spring.jmx.default-domain= # JMX domain name. spring.jmx.enabled=true # Expose management beans to the JMX domain. spring.jmx.server=mbeanServer # MBeanServer bean name. # Email (MailProperties) spring.mail.default-encoding=UTF-8 # Default MimeMessage encoding. spring.mail.host= # SMTP server host. For instance `smtp.example.com` spring.mail.jndi-name= # Session JNDI name. When set, takes precedence to others mail settings. spring.mail.password= # Login password of the SMTP server. spring.mail.port= # SMTP server port. spring.mail.properties.*= # Additional JavaMail session properties. spring.mail.protocol=smtp # Protocol used by the SMTP server. spring.mail.test-connection=false # Test that the mail server is available on startup. spring.mail.username= # Login user of the SMTP server. # APPLICATION SETTINGS (SpringApplication) spring.main.banner-mode=console # Mode used to display the banner when the application runs. spring.main.sources= # Sources (class name, package name or XML resource location) to include in the ApplicationContext. spring.main.web-environment= # Run the application in a web environment (auto-detected by default). # FILE ENCODING (FileEncodingApplicationListener) spring.mandatory-file-encoding= # Expected character encoding the application must use. # INTERNATIONALIZATION (MessageSourceAutoConfiguration) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 264 spring.messages.always-use-message-format=false # Set whether to always apply the MessageFormat rules, parsing even messages without arguments. spring.messages.basename=messages # Comma-separated list of basenames, each following the ResourceBundle convention. spring.messages.cache-seconds=-1 # Loaded resource bundle files cache expiration, in seconds. When set to -1, bundles are cached forever. spring.messages.encoding=UTF-8 # Message bundles encoding. spring.messages.fallback-to-system-locale=true # Set whether to fall back to the system Locale if no files for a specific Locale have been found. # OUTPUT spring.output.ansi.enabled=detect # Configure the ANSI output (can be "detect", "always", "never"). # PID FILE (ApplicationPidFileWriter) spring.pid.fail-on-write-error= # Fail if ApplicationPidFileWriter is used but it cannot write the PID file. spring.pid.file= # Location of the PID file to write (if ApplicationPidFileWriter is used). # PROFILES spring.profiles.active= # Comma-separated list of active profiles. spring.profiles.include= # Unconditionally activate the specified comma separated profiles. # SENDGRID (SendGridAutoConfiguration) spring.sendgrid.api-key= # SendGrid api key (alternative to username/password) spring.sendgrid.username= # SendGrid account username spring.sendgrid.password= # SendGrid account password spring.sendgrid.proxy.host= # SendGrid proxy host spring.sendgrid.proxy.port= # SendGrid proxy port # ---------------------------------------- # WEB PROPERTIES # ---------------------------------------- # EMBEDDED SERVER CONFIGURATION (ServerProperties) server.address= # Network address to which the server should bind to. server.compression.enabled=false # If response compression is enabled. server.compression.excluded-user-agents= # List of user-agents to exclude from compression. server.compression.mime-types= # Comma-separated list of MIME types that should be compressed. For instance `text/html,text/css,application/json` server.compression.min-response-size= # Minimum response size that is required for compression to be performed. For instance 2048 server.context-parameters.*= # Servlet context init parameters. For instance `server.context- parameters.a=alpha` server.context-path= # Context path of the application. server.display-name=application # Display name of the application. server.max-http-header-size=0 # Maximum size in bytes of the HTTP message header. server.max-http-post-size=0 # Maximum size in bytes of the HTTP post content. server.error.include-stacktrace=never # When to include a "stacktrace" attribute. server.error.path=/error # Path of the error controller. server.error.whitelabel.enabled=true # Enable the default error page displayed in browsers in case of a server error. server.jetty.acceptors= # Number of acceptor threads to use. server.jetty.selectors= # Number of selector threads to use. server.jsp-servlet.class-name=org.apache.jasper.servlet.JspServlet # The class name of the JSP servlet. server.jsp-servlet.init-parameters.*= # Init parameters used to configure the JSP servlet server.jsp-servlet.registered=true # Whether or not the JSP servlet is registered server.port=8080 # Server HTTP port. server.server-header= # The value sent in the server response header (uses servlet container default if empty) server.servlet-path=/ # Path of the main dispatcher servlet. server.use-forward-headers= # If X-Forwarded-* headers should be applied to the HttpRequest. server.session.cookie.comment= # Comment for the session cookie. server.session.cookie.domain= # Domain for the session cookie. server.session.cookie.http-only= # "HttpOnly" flag for the session cookie. server.session.cookie.max-age= # Maximum age of the session cookie in seconds. server.session.cookie.name= # Session cookie name. server.session.cookie.path= # Path of the session cookie. server.session.cookie.secure= # "Secure" flag for the session cookie. server.session.persistent=false # Persist session data between restarts. server.session.store-dir= # Directory used to store session data. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 265 server.session.timeout= # Session timeout in seconds. server.session.tracking-modes= # Session tracking modes (one or more of the following: "cookie", "url", "ssl"). server.ssl.ciphers= # Supported SSL ciphers. server.ssl.client-auth= # Whether client authentication is wanted ("want") or needed ("need"). Requires a trust store. server.ssl.enabled= # Enable SSL support. server.ssl.enabled-protocols= # Enabled SSL protocols. server.ssl.key-alias= # Alias that identifies the key in the key store. server.ssl.key-password= # Password used to access the key in the key store. server.ssl.key-store= # Path to the key store that holds the SSL certificate (typically a jks file). server.ssl.key-store-password= # Password used to access the key store. server.ssl.key-store-provider= # Provider for the key store. server.ssl.key-store-type= # Type of the key store. server.ssl.protocol=TLS # SSL protocol to use. server.ssl.trust-store= # Trust store that holds SSL certificates. server.ssl.trust-store-password= # Password used to access the trust store. server.ssl.trust-store-provider= # Provider for the trust store. server.ssl.trust-store-type= # Type of the trust store. server.tomcat.accesslog.directory=logs # Directory in which log files are created. Can be relative to the tomcat base dir or absolute. server.tomcat.accesslog.enabled=false # Enable access log. server.tomcat.accesslog.pattern=common # Format pattern for access logs. server.tomcat.accesslog.prefix=access_log # Log file name prefix. server.tomcat.accesslog.suffix=.log # Log file name suffix. server.tomcat.background-processor-delay=30 # Delay in seconds between the invocation of backgroundProcess methods. server.tomcat.basedir= # Tomcat base directory. If not specified a temporary directory will be used. server.tomcat.internal-proxies=10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\\ 192\\.168\\.\\d{1,3}\\.\\d{1,3}|\\ 169\\.254\\.\\d{1,3}\\.\\d{1,3}|\\ 127\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\\ 172\\.1[6-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\\ 172\\.2[0-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\\ 172\\.3[0-1]{1}\\.\\d{1,3}\\.\\d{1,3} # regular expression matching trusted IP addresses. server.tomcat.max-threads=0 # Maximum amount of worker threads. server.tomcat.min-spare-threads=0 # Minimum amount of worker threads. server.tomcat.port-header=X-Forwarded-Port # Name of the HTTP header used to override the original port value. server.tomcat.protocol-header= # Header that holds the incoming protocol, usually named "X-Forwarded- Proto". server.tomcat.protocol-header-https-value=https # Value of the protocol header that indicates that the incoming request uses SSL. server.tomcat.remote-ip-header= # Name of the http header from which the remote ip is extracted. For instance `X-FORWARDED-FOR` server.tomcat.uri-encoding=UTF-8 # Character encoding to use to decode the URI. server.undertow.accesslog.dir= # Undertow access log directory. server.undertow.accesslog.enabled=false # Enable access log. server.undertow.accesslog.pattern=common # Format pattern for access logs. server.undertow.buffer-size= # Size of each buffer in bytes. server.undertow.buffers-per-region= # Number of buffer per region. server.undertow.direct-buffers= # Allocate buffers outside the Java heap. server.undertow.io-threads= # Number of I/O threads to create for the worker. server.undertow.worker-threads= # Number of worker threads. # FREEMARKER (FreeMarkerAutoConfiguration) spring.freemarker.allow-request-override=false # Set whether HttpServletRequest attributes are allowed to override (hide) controller generated model attributes of the same name. spring.freemarker.allow-session-override=false # Set whether HttpSession attributes are allowed to override (hide) controller generated model attributes of the same name. spring.freemarker.cache=false # Enable template caching. spring.freemarker.charset=UTF-8 # Template encoding. spring.freemarker.check-template-location=true # Check that the templates location exists. spring.freemarker.content-type=text/html # Content-Type value. spring.freemarker.enabled=true # Enable MVC view resolution for this technology. spring.freemarker.expose-request-attributes=false # Set whether all request attributes should be added to the model prior to merging with the template. spring.freemarker.expose-session-attributes=false # Set whether all HttpSession attributes should be added to the model prior to merging with the template. spring.freemarker.expose-spring-macro-helpers=true # Set whether to expose a RequestContext for use by Spring's macro library, under the name "springMacroRequestContext". Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 266 spring.freemarker.prefer-file-system-access=true # Prefer file system access for template loading. File system access enables hot detection of template changes. spring.freemarker.prefix= # Prefix that gets prepended to view names when building a URL. spring.freemarker.request-context-attribute= # Name of the RequestContext attribute for all views. spring.freemarker.settings.*= # Well-known FreeMarker keys which will be passed to FreeMarker's Configuration. spring.freemarker.suffix= # Suffix that gets appended to view names when building a URL. spring.freemarker.template-loader-path=classpath:/templates/ # Comma-separated list of template paths. spring.freemarker.view-names= # White list of view names that can be resolved. # GROOVY TEMPLATES (GroovyTemplateAutoConfiguration) spring.groovy.template.allow-request-override=false # Set whether HttpServletRequest attributes are allowed to override (hide) controller generated model attributes of the same name. spring.groovy.template.allow-session-override=false # Set whether HttpSession attributes are allowed to override (hide) controller generated model attributes of the same name. spring.groovy.template.cache= # Enable template caching. spring.groovy.template.charset=UTF-8 # Template encoding. spring.groovy.template.check-template-location=true # Check that the templates location exists. spring.groovy.template.configuration.*= # See GroovyMarkupConfigurer spring.groovy.template.content-type=test/html # Content-Type value. spring.groovy.template.enabled=true # Enable MVC view resolution for this technology. spring.groovy.template.expose-request-attributes=false # Set whether all request attributes should be added to the model prior to merging with the template. spring.groovy.template.expose-session-attributes=false # Set whether all HttpSession attributes should be added to the model prior to merging with the template. spring.groovy.template.expose-spring-macro-helpers=true # Set whether to expose a RequestContext for use by Spring's macro library, under the name "springMacroRequestContext". spring.groovy.template.prefix= # Prefix that gets prepended to view names when building a URL. spring.groovy.template.request-context-attribute= # Name of the RequestContext attribute for all views. spring.groovy.template.resource-loader-path=classpath:/templates/ # Template path. spring.groovy.template.suffix=.tpl # Suffix that gets appended to view names when building a URL. spring.groovy.template.view-names= # White list of view names that can be resolved. # SPRING HATEOAS (HateoasProperties) spring.hateoas.use-hal-as-default-json-media-type=true # Specify if application/hal+json responses should be sent to requests that accept application/json. # HTTP message conversion spring.http.converters.preferred-json-mapper=jackson # Preferred JSON mapper to use for HTTP message conversion. Set to "gson" to force the use of Gson when both it and Jackson are on the classpath. # HTTP encoding (HttpEncodingProperties) spring.http.encoding.charset=UTF-8 # Charset of HTTP requests and responses. Added to the "Content-Type" header if not set explicitly. spring.http.encoding.enabled=true # Enable http encoding support. spring.http.encoding.force= # Force the encoding to the configured charset on HTTP requests and responses. spring.http.encoding.force-request= # Force the encoding to the configured charset on HTTP requests. Defaults to true when "force" has not been specified. spring.http.encoding.force-response= # Force the encoding to the configured charset on HTTP responses. # MULTIPART (MultipartProperties) spring.http.multipart.enabled=true # Enable support of multi-part uploads. spring.http.multipart.file-size-threshold=0 # Threshold after which files will be written to disk. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or Kilobyte size. spring.http.multipart.location= # Intermediate location of uploaded files. spring.http.multipart.max-file-size=1Mb # Max file size. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or Kilobyte size. spring.http.multipart.max-request-size=10Mb # Max request size. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or Kilobyte size. # JACKSON (JacksonProperties) spring.jackson.date-format= # Date format string or a fully-qualified date format class name. For instance `yyyy-MM-dd HH:mm:ss`. spring.jackson.default-property-inclusion= # Controls the inclusion of properties during serialization. spring.jackson.deserialization.*= # Jackson on/off features that affect the way Java objects are deserialized. spring.jackson.generator.*= # Jackson on/off features for generators. spring.jackson.joda-date-time-format= # Joda date time format string. If not configured, "date-format" will be used as a fallback if it is configured with a format string. spring.jackson.locale= # Locale used for formatting. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 267 spring.jackson.mapper.*= # Jackson general purpose on/off features. spring.jackson.parser.*= # Jackson on/off features for parsers. spring.jackson.property-naming-strategy= # One of the constants on Jackson's PropertyNamingStrategy. Can also be a fully-qualified class name of a PropertyNamingStrategy subclass. spring.jackson.serialization.*= # Jackson on/off features that affect the way Java objects are serialized. spring.jackson.serialization-inclusion= # Controls the inclusion of properties during serialization. Configured with one of the values in Jackson's JsonInclude.Include enumeration. spring.jackson.time-zone= # Time zone used when formatting dates. For instance `America/Los_Angeles` # JERSEY (JerseyProperties) spring.jersey.application-path= # Path that serves as the base URI for the application. Overrides the value of "@ApplicationPath" if specified. spring.jersey.filter.order=0 # Jersey filter chain order. spring.jersey.init.*= # Init parameters to pass to Jersey via the servlet or filter. spring.jersey.servlet.load-on-startup=-1 # Load on startup priority of the Jersey servlet. spring.jersey.type=servlet # Jersey integration type. Can be either "servlet" or "filter". # SPRING MOBILE DEVICE VIEWS (DeviceDelegatingViewResolverAutoConfiguration) spring.mobile.devicedelegatingviewresolver.enable-fallback=false # Enable support for fallback resolution. spring.mobile.devicedelegatingviewresolver.enabled=false # Enable device view resolver. spring.mobile.devicedelegatingviewresolver.mobile-prefix=mobile/ # Prefix that gets prepended to view names for mobile devices. spring.mobile.devicedelegatingviewresolver.mobile-suffix= # Suffix that gets appended to view names for mobile devices. spring.mobile.devicedelegatingviewresolver.normal-prefix= # Prefix that gets prepended to view names for normal devices. spring.mobile.devicedelegatingviewresolver.normal-suffix= # Suffix that gets appended to view names for normal devices. spring.mobile.devicedelegatingviewresolver.tablet-prefix=tablet/ # Prefix that gets prepended to view names for tablet devices. spring.mobile.devicedelegatingviewresolver.tablet-suffix= # Suffix that gets appended to view names for tablet devices. # SPRING MOBILE SITE PREFERENCE (SitePreferenceAutoConfiguration) spring.mobile.sitepreference.enabled=true # Enable SitePreferenceHandler. # MUSTACHE TEMPLATES (MustacheAutoConfiguration) spring.mustache.allow-request-override= # Set whether HttpServletRequest attributes are allowed to override (hide) controller generated model attributes of the same name. spring.mustache.allow-session-override= # Set whether HttpSession attributes are allowed to override (hide) controller generated model attributes of the same name. spring.mustache.cache= # Enable template caching. spring.mustache.charset= # Template encoding. spring.mustache.check-template-location= # Check that the templates location exists. spring.mustache.content-type= # Content-Type value. spring.mustache.enabled= # Enable MVC view resolution for this technology. spring.mustache.expose-request-attributes= # Set whether all request attributes should be added to the model prior to merging with the template. spring.mustache.expose-session-attributes= # Set whether all HttpSession attributes should be added to the model prior to merging with the template. spring.mustache.expose-spring-macro-helpers= # Set whether to expose a RequestContext for use by Spring's macro library, under the name "springMacroRequestContext". spring.mustache.prefix=classpath:/templates/ # Prefix to apply to template names. spring.mustache.request-context-attribute= # Name of the RequestContext attribute for all views. spring.mustache.suffix=.html # Suffix to apply to template names. spring.mustache.view-names= # White list of view names that can be resolved. # SPRING MVC (WebMvcProperties) spring.mvc.async.request-timeout= # Amount of time (in milliseconds) before asynchronous request handling times out. spring.mvc.date-format= # Date format to use. For instance `dd/MM/yyyy`. spring.mvc.dispatch-trace-request=false # Dispatch TRACE requests to the FrameworkServlet doService method. spring.mvc.dispatch-options-request=false # Dispatch OPTIONS requests to the FrameworkServlet doService method. spring.mvc.favicon.enabled=true # Enable resolution of favicon.ico. spring.mvc.ignore-default-model-on-redirect=true # If the content of the "default" model should be ignored during redirect scenarios. spring.mvc.locale= # Locale to use. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 268 spring.mvc.media-types.*= # Maps file extensions to media types for content negotiation. spring.mvc.message-codes-resolver-format= # Formatting strategy for message codes. For instance `PREFIX_ERROR_CODE`. spring.mvc.servlet.load-on-startup=-1 # Load on startup priority of the Spring Web Services servlet. spring.mvc.static-path-pattern=/** # Path pattern used for static resources. spring.mvc.throw-exception-if-no-handler-found=false # If a "NoHandlerFoundException" should be thrown if no Handler was found to process a request. spring.mvc.view.prefix= # Spring MVC view prefix. spring.mvc.view.suffix= # Spring MVC view suffix. # SPRING RESOURCES HANDLING (ResourceProperties) spring.resources.add-mappings=true # Enable default resource handling. spring.resources.cache-period= # Cache period for the resources served by the resource handler, in seconds. spring.resources.chain.cache=true # Enable caching in the Resource chain. spring.resources.chain.enabled= # Enable the Spring Resource Handling chain. Disabled by default unless at least one strategy has been enabled. spring.resources.chain.gzipped=false # Enable resolution of already gzipped resources. spring.resources.chain.html-application-cache=false # Enable HTML5 application cache manifest rewriting. spring.resources.chain.strategy.content.enabled=false # Enable the content Version Strategy. spring.resources.chain.strategy.content.paths=/** # Comma-separated list of patterns to apply to the Version Strategy. spring.resources.chain.strategy.fixed.enabled=false # Enable the fixed Version Strategy. spring.resources.chain.strategy.fixed.paths=/** # Comma-separated list of patterns to apply to the Version Strategy. spring.resources.chain.strategy.fixed.version= # Version string to use for the Version Strategy. spring.resources.static-locations=classpath:/META-INF/resources/,classpath:/resources/,classpath:/ static/,classpath:/public/ # Locations of static resources. # SPRING SESSION (SessionProperties) spring.session.hazelcast.map-name=spring:session:sessions # Name of the map used to store sessions. spring.session.jdbc.table-name=SPRING_SESSION # Name of database table used to store sessions. spring.session.mongo.collection-name=sessions # Collection name used to store sessions. spring.session.redis.flush-mode= # Flush mode for the Redis sessions. spring.session.redis.namespace= # Namespace for keys used to store sessions. spring.session.store-type= # Session store type. # SPRING SOCIAL (SocialWebAutoConfiguration) spring.social.auto-connection-views=false # Enable the connection status view for supported providers. # SPRING SOCIAL FACEBOOK (FacebookAutoConfiguration) spring.social.facebook.app-id= # your application's Facebook App ID spring.social.facebook.app-secret= # your application's Facebook App Secret # SPRING SOCIAL LINKEDIN (LinkedInAutoConfiguration) spring.social.linkedin.app-id= # your application's LinkedIn App ID spring.social.linkedin.app-secret= # your application's LinkedIn App Secret # SPRING SOCIAL TWITTER (TwitterAutoConfiguration) spring.social.twitter.app-id= # your application's Twitter App ID spring.social.twitter.app-secret= # your application's Twitter App Secret # THYMELEAF (ThymeleafAutoConfiguration) spring.thymeleaf.cache=true # Enable template caching. spring.thymeleaf.check-template-location=true # Check that the templates location exists. spring.thymeleaf.content-type=text/html # Content-Type value. spring.thymeleaf.enabled=true # Enable MVC Thymeleaf view resolution. spring.thymeleaf.encoding=UTF-8 # Template encoding. spring.thymeleaf.excluded-view-names= # Comma-separated list of view names that should be excluded from resolution. spring.thymeleaf.mode=HTML5 # Template mode to be applied to templates. See also StandardTemplateModeHandlers. spring.thymeleaf.prefix=classpath:/templates/ # Prefix that gets prepended to view names when building a URL. spring.thymeleaf.suffix=.html # Suffix that gets appended to view names when building a URL. spring.thymeleaf.template-resolver-order= # Order of the template resolver in the chain. spring.thymeleaf.view-names= # Comma-separated list of view names that can be resolved. # VELOCITY TEMPLATES (VelocityAutoConfiguration) spring.velocity.allow-request-override=false # Set whether HttpServletRequest attributes are allowed to override (hide) controller generated model attributes of the same name. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 269 spring.velocity.allow-session-override=false # Set whether HttpSession attributes are allowed to override (hide) controller generated model attributes of the same name. spring.velocity.cache= # Enable template caching. spring.velocity.charset=UTF-8 # Template encoding. spring.velocity.check-template-location=true # Check that the templates location exists. spring.velocity.content-type=text/html # Content-Type value. spring.velocity.date-tool-attribute= # Name of the DateTool helper object to expose in the Velocity context of the view. spring.velocity.enabled=true # Enable MVC view resolution for this technology. spring.velocity.expose-request-attributes=false # Set whether all request attributes should be added to the model prior to merging with the template. spring.velocity.expose-session-attributes=false # Set whether all HttpSession attributes should be added to the model prior to merging with the template. spring.velocity.expose-spring-macro-helpers=true # Set whether to expose a RequestContext for use by Spring's macro library, under the name "springMacroRequestContext". spring.velocity.number-tool-attribute= # Name of the NumberTool helper object to expose in the Velocity context of the view. spring.velocity.prefer-file-system-access=true # Prefer file system access for template loading. File system access enables hot detection of template changes. spring.velocity.prefix= # Prefix that gets prepended to view names when building a URL. spring.velocity.properties.*= # Additional velocity properties. spring.velocity.request-context-attribute= # Name of the RequestContext attribute for all views. spring.velocity.resource-loader-path=classpath:/templates/ # Template path. spring.velocity.suffix=.vm # Suffix that gets appended to view names when building a URL. spring.velocity.toolbox-config-location= # Velocity Toolbox config location. For instance `/WEB-INF/ toolbox.xml` spring.velocity.view-names= # White list of view names that can be resolved. # SPRING WEB SERVICES (WebServicesProperties) spring.webservices.path=/services # Path that serves as the base URI for the services. spring.webservices.servlet.init= # Servlet init parameters to pass to Spring Web Services. spring.webservices.servlet.load-on-startup=-1 # Load on startup priority of the Spring Web Services servlet. # ---------------------------------------- # SECURITY PROPERTIES # ---------------------------------------- # SECURITY (SecurityProperties) security.basic.authorize-mode=role # Security authorize mode to apply. security.basic.enabled=true # Enable basic authentication. security.basic.path=/** # Comma-separated list of paths to secure. security.basic.realm=Spring # HTTP basic realm name. security.enable-csrf=false # Enable Cross Site Request Forgery support. security.filter-order=0 # Security filter chain order. security.filter-dispatcher-types=ASYNC, FORWARD, INCLUDE, REQUEST # Security filter chain dispatcher types. security.headers.cache=true # Enable cache control HTTP headers. security.headers.content-type=true # Enable "X-Content-Type-Options" header. security.headers.frame=true # Enable "X-Frame-Options" header. security.headers.hsts= # HTTP Strict Transport Security (HSTS) mode (none, domain, all). security.headers.xss=true # Enable cross site scripting (XSS) protection. security.ignored= # Comma-separated list of paths to exclude from the default secured paths. security.require-ssl=false # Enable secure channel for all requests. security.sessions=stateless # Session creation policy (always, never, if_required, stateless). security.user.name=user # Default user name. security.user.password= # Password for the default user name. A random password is logged on startup by default. security.user.role=USER # Granted roles for the default user name. # SECURITY OAUTH2 CLIENT (OAuth2ClientProperties security.oauth2.client.client-id= # OAuth2 client id. security.oauth2.client.client-secret= # OAuth2 client secret. A random secret is generated by default # SECURITY OAUTH2 RESOURCES (ResourceServerProperties security.oauth2.resource.id= # Identifier of the resource. security.oauth2.resource.jwt.key-uri= # The URI of the JWT token. Can be set if the value is not available and the key is public. security.oauth2.resource.jwt.key-value= # The verification key of the JWT token. Can either be a symmetric secret or PEM-encoded RSA public key. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 270 security.oauth2.resource.prefer-token-info=true # Use the token info, can be set to false to use the user info. security.oauth2.resource.service-id=resource # security.oauth2.resource.token-info-uri= # URI of the token decoding endpoint. security.oauth2.resource.token-type= # The token type to send when using the userInfoUri. security.oauth2.resource.user-info-uri= # URI of the user endpoint. # SECURITY OAUTH2 SSO (OAuth2SsoProperties security.oauth2.sso.filter-order= # Filter order to apply if not providing an explicit WebSecurityConfigurerAdapter security.oauth2.sso.login-path=/login # Path to the login page, i.e. the one that triggers the redirect to the OAuth2 Authorization Server # ---------------------------------------- # DATA PROPERTIES # ---------------------------------------- # FLYWAY (FlywayProperties) flyway.baseline-description= # flyway.baseline-version=1 # version to start migration flyway.baseline-on-migrate= # flyway.check-location=false # Check that migration scripts location exists. flyway.clean-on-validation-error= # flyway.enabled=true # Enable flyway. flyway.encoding= # flyway.ignore-failed-future-migration= # flyway.init-sqls= # SQL statements to execute to initialize a connection immediately after obtaining it. flyway.locations=classpath:db/migration # locations of migrations scripts flyway.out-of-order= # flyway.password= # JDBC password if you want Flyway to create its own DataSource flyway.placeholder-prefix= # flyway.placeholder-replacement= # flyway.placeholder-suffix= # flyway.placeholders.*= # flyway.schemas= # schemas to update flyway.sql-migration-prefix=V # flyway.sql-migration-separator= # flyway.sql-migration-suffix=.sql # flyway.table= # flyway.url= # JDBC url of the database to migrate. If not set, the primary configured data source is used. flyway.user= # Login user of the database to migrate. flyway.validate-on-migrate= # # LIQUIBASE (LiquibaseProperties) liquibase.change-log=classpath:/db/changelog/db.changelog-master.yaml # Change log configuration path. liquibase.check-change-log-location=true # Check the change log location exists. liquibase.contexts= # Comma-separated list of runtime contexts to use. liquibase.default-schema= # Default database schema. liquibase.drop-first=false # Drop the database schema first. liquibase.enabled=true # Enable liquibase support. liquibase.labels= # Comma-separated list of runtime labels to use. liquibase.parameters.*= # Change log parameters. liquibase.password= # Login password of the database to migrate. liquibase.rollback-file= # File to which rollback SQL will be written when an update is performed. liquibase.url= # JDBC url of the database to migrate. If not set, the primary configured data source is used. liquibase.user= # Login user of the database to migrate. # COUCHBASE (CouchbaseProperties) spring.couchbase.bootstrap-hosts= # Couchbase nodes (host or IP address) to bootstrap from. spring.couchbase.bucket.name=default # Name of the bucket to connect to. spring.couchbase.bucket.password= # Password of the bucket. spring.couchbase.env.endpoints.key-value=1 # Number of sockets per node against the Key/value service. spring.couchbase.env.endpoints.query=1 # Number of sockets per node against the Query (N1QL) service. spring.couchbase.env.endpoints.view=1 # Number of sockets per node against the view service. spring.couchbase.env.ssl.enabled= # Enable SSL support. Enabled automatically if a "keyStore" is provided unless specified otherwise. spring.couchbase.env.ssl.key-store= # Path to the JVM key store that holds the certificates. spring.couchbase.env.ssl.key-store-password= # Password used to access the key store. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 271 spring.couchbase.env.timeouts.connect=5000 # Bucket connections timeout in milliseconds. spring.couchbase.env.timeouts.key-value=2500 # Blocking operations performed on a specific key timeout in milliseconds. spring.couchbase.env.timeouts.query=7500 # N1QL query operations timeout in milliseconds. spring.couchbase.env.timeouts.socket-connect=1000 # Socket connect connections timeout in milliseconds. spring.couchbase.env.timeouts.view=7500 # Regular and geospatial view operations timeout in milliseconds. # DAO (PersistenceExceptionTranslationAutoConfiguration) spring.dao.exceptiontranslation.enabled=true # Enable the PersistenceExceptionTranslationPostProcessor. # CASSANDRA (CassandraProperties) spring.data.cassandra.cluster-name= # Name of the Cassandra cluster. spring.data.cassandra.compression= # Compression supported by the Cassandra binary protocol. spring.data.cassandra.connect-timeout-millis= # Socket option: connection time out. spring.data.cassandra.consistency-level= # Queries consistency level. spring.data.cassandra.contact-points=localhost # Comma-separated list of cluster node addresses. spring.data.cassandra.fetch-size= # Queries default fetch size. spring.data.cassandra.keyspace-name= # Keyspace name to use. spring.data.cassandra.load-balancing-policy= # Class name of the load balancing policy. spring.data.cassandra.port= # Port of the Cassandra server. spring.data.cassandra.password= # Login password of the server. spring.data.cassandra.read-timeout-millis= # Socket option: read time out. spring.data.cassandra.reconnection-policy= # Reconnection policy class. spring.data.cassandra.retry-policy= # Class name of the retry policy. spring.data.cassandra.serial-consistency-level= # Queries serial consistency level. spring.data.cassandra.ssl=false # Enable SSL support. spring.data.cassandra.username= # Login user of the server. # DATA COUCHBASE (CouchbaseDataProperties) spring.data.couchbase.auto-index=false # Automatically create views and indexes. spring.data.couchbase.consistency=read-your-own-writes # Consistency to apply by default on generated queries. spring.data.couchbase.repositories.enabled=true # Enable Couchbase repositories. # ELASTICSEARCH (ElasticsearchProperties) spring.data.elasticsearch.cluster-name=elasticsearch # Elasticsearch cluster name. spring.data.elasticsearch.cluster-nodes= # Comma-separated list of cluster node addresses. If not specified, starts a client node. spring.data.elasticsearch.properties.*= # Additional properties used to configure the client. spring.data.elasticsearch.repositories.enabled=true # Enable Elasticsearch repositories. # MONGODB (MongoProperties) spring.data.mongodb.authentication-database= # Authentication database name. spring.data.mongodb.database=test # Database name. spring.data.mongodb.field-naming-strategy= # Fully qualified name of the FieldNamingStrategy to use. spring.data.mongodb.grid-fs-database= # GridFS database name. spring.data.mongodb.host=localhost # Mongo server host. spring.data.mongodb.password= # Login password of the mongo server. spring.data.mongodb.port=27017 # Mongo server port. spring.data.mongodb.repositories.enabled=true # Enable Mongo repositories. spring.data.mongodb.uri=mongodb://localhost/test # Mongo database URI. When set, host and port are ignored. spring.data.mongodb.username= # Login user of the mongo server. # DATA REDIS spring.data.redis.repositories.enabled=true # Enable Redis repositories. # NEO4J (Neo4jProperties) spring.data.neo4j.compiler= # Compiler to use. spring.data.neo4j.embedded.enabled=true # Enable embedded mode if the embedded driver is available. spring.data.neo4j.password= # Login password of the server. spring.data.neo4j.repositories.enabled=true # Enable Neo4j repositories. spring.data.neo4j.session.scope=singleton # Scope (lifetime) of the session. spring.data.neo4j.uri= # URI used by the driver. Auto-detected by default. spring.data.neo4j.username= # Login user of the server. # DATA REST (RepositoryRestProperties) spring.data.rest.base-path= # Base path to be used by Spring Data REST to expose repository resources. spring.data.rest.default-page-size= # Default size of pages. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 272 spring.data.rest.enable-enum-translation= # Enable enum value translation via the Spring Data REST default resource bundle. spring.data.rest.limit-param-name= # Name of the URL query string parameter that indicates how many results to return at once. spring.data.rest.max-page-size= # Maximum size of pages. spring.data.rest.page-param-name= # Name of the URL query string parameter that indicates what page to return. spring.data.rest.return-body-on-create= # Return a response body after creating an entity. spring.data.rest.return-body-on-update= # Return a response body after updating an entity. spring.data.rest.sort-param-name= # Name of the URL query string parameter that indicates what direction to sort results. # SOLR (SolrProperties) spring.data.solr.host=http://127.0.0.1:8983/solr # Solr host. Ignored if "zk-host" is set. spring.data.solr.repositories.enabled=true # Enable Solr repositories. spring.data.solr.zk-host= # ZooKeeper host address in the form HOST:PORT. # DATASOURCE (DataSourceAutoConfiguration & DataSourceProperties) spring.datasource.continue-on-error=false # Do not stop if an error occurs while initializing the database. spring.datasource.data= # Data (DML) script resource reference. spring.datasource.data-username= # User of the database to execute DML scripts (if different). spring.datasource.data-password= # Password of the database to execute DML scripts (if different). spring.datasource.dbcp.*= # Commons DBCP specific settings spring.datasource.dbcp2.*= # Commons DBCP2 specific settings spring.datasource.driver-class-name= # Fully qualified name of the JDBC driver. Auto-detected based on the URL by default. spring.datasource.hikari.*= # Hikari specific settings spring.datasource.initialize=true # Populate the database using 'data.sql'. spring.datasource.jmx-enabled=false # Enable JMX support (if provided by the underlying pool). spring.datasource.jndi-name= # JNDI location of the datasource. Class, url, username & password are ignored when set. spring.datasource.name=testdb # Name of the datasource. spring.datasource.password= # Login password of the database. spring.datasource.platform=all # Platform to use in the schema resource (schema-${platform}.sql). spring.datasource.schema= # Schema (DDL) script resource reference. spring.datasource.schema-username= # User of the database to execute DDL scripts (if different). spring.datasource.schema-password= # Password of the database to execute DDL scripts (if different). spring.datasource.separator=; # Statement separator in SQL initialization scripts. spring.datasource.sql-script-encoding= # SQL scripts encoding. spring.datasource.tomcat.*= # Tomcat datasource specific settings spring.datasource.type= # Fully qualified name of the connection pool implementation to use. By default, it is auto-detected from the classpath. spring.datasource.url= # JDBC url of the database. spring.datasource.username= # H2 Web Console (H2ConsoleProperties) spring.h2.console.enabled=false # Enable the console. spring.h2.console.path=/h2-console # Path at which the console will be available. spring.h2.console.settings.trace=false # Enable trace output. spring.h2.console.settings.web-allow-others=false # Enable remote access. # JOOQ (JooqAutoConfiguration) spring.jooq.sql-dialect= # SQLDialect JOOQ used when communicating with the configured datasource. For instance `POSTGRES` # JPA (JpaBaseConfiguration, HibernateJpaAutoConfiguration) spring.data.jpa.repositories.enabled=true # Enable JPA repositories. spring.jpa.database= # Target database to operate on, auto-detected by default. Can be alternatively set using the "databasePlatform" property. spring.jpa.database-platform= # Name of the target database to operate on, auto-detected by default. Can be alternatively set using the "Database" enum. spring.jpa.generate-ddl=false # Initialize the schema on startup. spring.jpa.hibernate.ddl-auto= # DDL mode. This is actually a shortcut for the "hibernate.hbm2ddl.auto" property. Default to "create-drop" when using an embedded database, "none" otherwise. spring.jpa.hibernate.naming.implicit-strategy= # Hibernate 5 implicit naming strategy fully qualified name. spring.jpa.hibernate.naming.physical-strategy= # Hibernate 5 physical naming strategy fully qualified name. spring.jpa.hibernate.naming.strategy= # Hibernate 4 naming strategy fully qualified name. Not supported with Hibernate 5. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 273 spring.jpa.hibernate.use-new-id-generator-mappings= # Use Hibernate's newer IdentifierGenerator for AUTO, TABLE and SEQUENCE. spring.jpa.open-in-view=true # Register OpenEntityManagerInViewInterceptor. Binds a JPA EntityManager to the thread for the entire processing of the request. spring.jpa.properties.*= # Additional native properties to set on the JPA provider. spring.jpa.show-sql=false # Enable logging of SQL statements. # JTA (JtaAutoConfiguration) spring.jta.enabled=true # Enable JTA support. spring.jta.log-dir= # Transaction logs directory. spring.jta.transaction-manager-id= # Transaction manager unique identifier. # ATOMIKOS (AtomikosProperties) spring.jta.atomikos.connectionfactory.borrow-connection-timeout=30 # Timeout, in seconds, for borrowing connections from the pool. spring.jta.atomikos.connectionfactory.ignore-session-transacted-flag=true # Whether or not to ignore the transacted flag when creating session. spring.jta.atomikos.connectionfactory.local-transaction-mode=false # Whether or not local transactions are desired. spring.jta.atomikos.connectionfactory.maintenance-interval=60 # The time, in seconds, between runs of the pool's maintenance thread. spring.jta.atomikos.connectionfactory.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the pool. spring.jta.atomikos.connectionfactory.max-lifetime=0 # The time, in seconds, that a connection can be pooled for before being destroyed. 0 denotes no limit. spring.jta.atomikos.connectionfactory.max-pool-size=1 # The maximum size of the pool. spring.jta.atomikos.connectionfactory.min-pool-size=1 # The minimum size of the pool. spring.jta.atomikos.connectionfactory.reap-timeout=0 # The reap timeout, in seconds, for borrowed connections. 0 denotes no limit. spring.jta.atomikos.connectionfactory.unique-resource-name=jmsConnectionFactory # The unique name used to identify the resource during recovery. spring.jta.atomikos.datasource.borrow-connection-timeout=30 # Timeout, in seconds, for borrowing connections from the pool. spring.jta.atomikos.datasource.default-isolation-level= # Default isolation level of connections provided by the pool. spring.jta.atomikos.datasource.login-timeout= # Timeout, in seconds, for establishing a database connection. spring.jta.atomikos.datasource.maintenance-interval=60 # The time, in seconds, between runs of the pool's maintenance thread. spring.jta.atomikos.datasource.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the pool. spring.jta.atomikos.datasource.max-lifetime=0 # The time, in seconds, that a connection can be pooled for before being destroyed. 0 denotes no limit. spring.jta.atomikos.datasource.max-pool-size=1 # The maximum size of the pool. spring.jta.atomikos.datasource.min-pool-size=1 # The minimum size of the pool. spring.jta.atomikos.datasource.reap-timeout=0 # The reap timeout, in seconds, for borrowed connections. 0 denotes no limit. spring.jta.atomikos.datasource.test-query= # SQL query or statement used to validate a connection before returning it. spring.jta.atomikos.datasource.unique-resource-name=dataSource # The unique name used to identify the resource during recovery. spring.jta.atomikos.properties.checkpoint-interval=500 # Interval between checkpoints. spring.jta.atomikos.properties.console-file-count=1 # Number of debug logs files that can be created. spring.jta.atomikos.properties.console-file-limit=-1 # How many bytes can be stored at most in debug logs files. spring.jta.atomikos.properties.console-file-name=tm.out # Debug logs file name. spring.jta.atomikos.properties.console-log-level= # Console log level. spring.jta.atomikos.properties.default-jta-timeout=10000 # Default timeout for JTA transactions. spring.jta.atomikos.properties.enable-logging=true # Enable disk logging. spring.jta.atomikos.properties.force-shutdown-on-vm-exit=false # Specify if a VM shutdown should trigger forced shutdown of the transaction core. spring.jta.atomikos.properties.log-base-dir= # Directory in which the log files should be stored. spring.jta.atomikos.properties.log-base-name=tmlog # Transactions log file base name. spring.jta.atomikos.properties.max-actives=50 # Maximum number of active transactions. spring.jta.atomikos.properties.max-timeout=300000 # Maximum timeout (in milliseconds) that can be allowed for transactions. spring.jta.atomikos.properties.output-dir= # Directory in which to store the debug log files. spring.jta.atomikos.properties.serial-jta-transactions=true # Specify if sub-transactions should be joined when possible. spring.jta.atomikos.properties.service= # Transaction manager implementation that should be started. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 274 spring.jta.atomikos.properties.threaded-two-phase-commit=true # Use different (and concurrent) threads for two-phase commit on the participating resources. spring.jta.atomikos.properties.transaction-manager-unique-name= # Transaction manager's unique name. # BITRONIX spring.jta.bitronix.connectionfactory.acquire-increment=1 # Number of connections to create when growing the pool. spring.jta.bitronix.connectionfactory.acquisition-interval=1 # Time, in seconds, to wait before trying to acquire a connection again after an invalid connection was acquired. spring.jta.bitronix.connectionfactory.acquisition-timeout=30 # Timeout, in seconds, for acquiring connections from the pool. spring.jta.bitronix.connectionfactory.allow-local-transactions=true # Whether or not the transaction manager should allow mixing XA and non-XA transactions. spring.jta.bitronix.connectionfactory.apply-transaction-timeout=false # Whether or not the transaction timeout should be set on the XAResource when it is enlisted. spring.jta.bitronix.connectionfactory.automatic-enlisting-enabled=true # Whether or not resources should be enlisted and delisted automatically. spring.jta.bitronix.connectionfactory.cache-producers-consumers=true # Whether or not produces and consumers should be cached. spring.jta.bitronix.connectionfactory.defer-connection-release=true # Whether or not the provider can run many transactions on the same connection and supports transaction interleaving. spring.jta.bitronix.connectionfactory.ignore-recovery-failures=false # Whether or not recovery failures should be ignored. spring.jta.bitronix.connectionfactory.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the pool. spring.jta.bitronix.connectionfactory.max-pool-size=10 # The maximum size of the pool. 0 denotes no limit. spring.jta.bitronix.connectionfactory.min-pool-size=0 # The minimum size of the pool. spring.jta.bitronix.connectionfactory.password= # The password to use to connect to the JMS provider. spring.jta.bitronix.connectionfactory.share-transaction-connections=false # Whether or not connections in the ACCESSIBLE state can be shared within the context of a transaction. spring.jta.bitronix.connectionfactory.test-connections=true # Whether or not connections should be tested when acquired from the pool. spring.jta.bitronix.connectionfactory.two-pc-ordering-position=1 # The position that this resource should take during two-phase commit (always first is Integer.MIN_VALUE, always last is Integer.MAX_VALUE). spring.jta.bitronix.connectionfactory.unique-name=jmsConnectionFactory # The unique name used to identify the resource during recovery. spring.jta.bitronix.connectionfactory.use-tm-join=true Whether or not TMJOIN should be used when starting XAResources. spring.jta.bitronix.connectionfactory.user= # The user to use to connect to the JMS provider. spring.jta.bitronix.datasource.acquire-increment=1 # Number of connections to create when growing the pool. spring.jta.bitronix.datasource.acquisition-interval=1 # Time, in seconds, to wait before trying to acquire a connection again after an invalid connection was acquired. spring.jta.bitronix.datasource.acquisition-timeout=30 # Timeout, in seconds, for acquiring connections from the pool. spring.jta.bitronix.datasource.allow-local-transactions=true # Whether or not the transaction manager should allow mixing XA and non-XA transactions. spring.jta.bitronix.datasource.apply-transaction-timeout=false # Whether or not the transaction timeout should be set on the XAResource when it is enlisted. spring.jta.bitronix.datasource.automatic-enlisting-enabled=true # Whether or not resources should be enlisted and delisted automatically. spring.jta.bitronix.datasource.cursor-holdability= # The default cursor holdability for connections. spring.jta.bitronix.datasource.defer-connection-release=true # Whether or not the database can run many transactions on the same connection and supports transaction interleaving. spring.jta.bitronix.datasource.enable-jdbc4-connection-test= # Whether or not Connection.isValid() is called when acquiring a connection from the pool. spring.jta.bitronix.datasource.ignore-recovery-failures=false # Whether or not recovery failures should be ignored. spring.jta.bitronix.datasource.isolation-level= # The default isolation level for connections. spring.jta.bitronix.datasource.local-auto-commit= # The default auto-commit mode for local transactions. spring.jta.bitronix.datasource.login-timeout= # Timeout, in seconds, for establishing a database connection. spring.jta.bitronix.datasource.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the pool. spring.jta.bitronix.datasource.max-pool-size=10 # The maximum size of the pool. 0 denotes no limit. spring.jta.bitronix.datasource.min-pool-size=0 # The minimum size of the pool. spring.jta.bitronix.datasource.prepared-statement-cache-size=0 # The target size of the prepared statement cache. 0 disables the cache. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 275 spring.jta.bitronix.datasource.share-transaction-connections=false # Whether or not connections in the ACCESSIBLE state can be shared within the context of a transaction. spring.jta.bitronix.datasource.test-query= # SQL query or statement used to validate a connection before returning it. spring.jta.bitronix.datasource.two-pc-ordering-position=1 # The position that this resource should take during two-phase commit (always first is Integer.MIN_VALUE, always last is Integer.MAX_VALUE). spring.jta.bitronix.datasource.unique-name=dataSource # The unique name used to identify the resource during recovery. spring.jta.bitronix.datasource.use-tm-join=true Whether or not TMJOIN should be used when starting XAResources. spring.jta.bitronix.properties.allow-multiple-lrc=false # Allow multiple LRC resources to be enlisted into the same transaction. spring.jta.bitronix.properties.asynchronous2-pc=false # Enable asynchronously execution of two phase commit. spring.jta.bitronix.properties.background-recovery-interval-seconds=60 # Interval in seconds at which to run the recovery process in the background. spring.jta.bitronix.properties.current-node-only-recovery=true # Recover only the current node. spring.jta.bitronix.properties.debug-zero-resource-transaction=false # Log the creation and commit call stacks of transactions executed without a single enlisted resource. spring.jta.bitronix.properties.default-transaction-timeout=60 # Default transaction timeout in seconds. spring.jta.bitronix.properties.disable-jmx=false # Enable JMX support. spring.jta.bitronix.properties.exception-analyzer= # Set the fully qualified name of the exception analyzer implementation to use. spring.jta.bitronix.properties.filter-log-status=false # Enable filtering of logs so that only mandatory logs are written. spring.jta.bitronix.properties.force-batching-enabled=true # Set if disk forces are batched. spring.jta.bitronix.properties.forced-write-enabled=true # Set if logs are forced to disk. spring.jta.bitronix.properties.graceful-shutdown-interval=60 # Maximum amount of seconds the TM will wait for transactions to get done before aborting them at shutdown time. spring.jta.bitronix.properties.jndi-transaction-synchronization-registry-name= # JNDI name of the TransactionSynchronizationRegistry. spring.jta.bitronix.properties.jndi-user-transaction-name= # JNDI name of the UserTransaction. spring.jta.bitronix.properties.journal=disk # Name of the journal. Can be 'disk', 'null' or a class name. spring.jta.bitronix.properties.log-part1-filename=btm1.tlog # Name of the first fragment of the journal. spring.jta.bitronix.properties.log-part2-filename=btm2.tlog # Name of the second fragment of the journal. spring.jta.bitronix.properties.max-log-size-in-mb=2 # Maximum size in megabytes of the journal fragments. spring.jta.bitronix.properties.resource-configuration-filename= # ResourceLoader configuration file name. spring.jta.bitronix.properties.server-id= # ASCII ID that must uniquely identify this TM instance. Default to the machine's IP address. spring.jta.bitronix.properties.skip-corrupted-logs=false # Skip corrupted transactions log entries. spring.jta.bitronix.properties.warn-about-zero-resource-transaction=true # Log a warning for transactions executed without a single enlisted resource. # NARAYANA (NarayanaProperties) spring.jta.narayana.default-timeout=60 # Transaction timeout in seconds. spring.jta.narayana.expiry- scanners=com.arjuna.ats.internal.arjuna.recovery.ExpiredTransactionStatusManagerScanner # Comma- separated list of expiry scanners. spring.jta.narayana.log-dir= # Transaction object store directory. spring.jta.narayana.one-phase-commit=true # Enable one phase commit optimisation. spring.jta.narayana.periodic-recovery-period=120 # Interval in which periodic recovery scans are performed in seconds. spring.jta.narayana.recovery-backoff-period=10 # Back off period between first and second phases of the recovery scan in seconds. spring.jta.narayana.recovery-db-pass= # Database password to be used by recovery manager. spring.jta.narayana.recovery-db-user= # Database username to be used by recovery manager. spring.jta.narayana.recovery-jms-pass= # JMS password to be used by recovery manager. spring.jta.narayana.recovery-jms-user= # JMS username to be used by recovery manager. spring.jta.narayana.recovery-modules= # Comma-separated list of recovery modules. spring.jta.narayana.transaction-manager-id=1 # Unique transaction manager id. spring.jta.narayana.xa-resource-orphan-filters= # Comma-separated list of orphan filters. # EMBEDDED MONGODB (EmbeddedMongoProperties) spring.mongodb.embedded.features=SYNC_DELAY # Comma-separated list of features to enable. spring.mongodb.embedded.storage.databaseDir= # Directory used for data storage. spring.mongodb.embedded.storage.oplogSize= # Maximum size of the oplog in megabytes. spring.mongodb.embedded.storage.replSetName= # Name of the replica set. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 276 spring.mongodb.embedded.version=2.6.10 # Version of Mongo to use. # REDIS (RedisProperties) spring.redis.cluster.max-redirects= # Maximum number of redirects to follow when executing commands across the cluster. spring.redis.cluster.nodes= # Comma-separated list of "host:port" pairs to bootstrap from. spring.redis.database=0 # Database index used by the connection factory. spring.redis.host=localhost # Redis server host. spring.redis.password= # Login password of the redis server. spring.redis.pool.max-active=8 # Max number of connections that can be allocated by the pool at a given time. Use a negative value for no limit. spring.redis.pool.max-idle=8 # Max number of "idle" connections in the pool. Use a negative value to indicate an unlimited number of idle connections. spring.redis.pool.max-wait=-1 # Maximum amount of time (in milliseconds) a connection allocation should block before throwing an exception when the pool is exhausted. Use a negative value to block indefinitely. spring.redis.pool.min-idle=0 # Target for the minimum number of idle connections to maintain in the pool. This setting only has an effect if it is positive. spring.redis.port=6379 # Redis server port. spring.redis.sentinel.master= # Name of Redis server. spring.redis.sentinel.nodes= # Comma-separated list of host:port pairs. spring.redis.timeout=0 # Connection timeout in milliseconds. # ---------------------------------------- # INTEGRATION PROPERTIES # ---------------------------------------- # ACTIVEMQ (ActiveMQProperties) spring.activemq.broker-url= # URL of the ActiveMQ broker. Auto-generated by default. For instance `tcp://localhost:61616` spring.activemq.in-memory=true # Specify if the default broker URL should be in memory. Ignored if an explicit broker has been specified. spring.activemq.password= # Login password of the broker. spring.activemq.user= # Login user of the broker. spring.activemq.packages.trust-all=false # Trust all packages. spring.activemq.packages.trusted= # Comma-separated list of specific packages to trust (when not trusting all packages). spring.activemq.pool.configuration.*= # See PooledConnectionFactory. spring.activemq.pool.enabled=false # Whether a PooledConnectionFactory should be created instead of a regular ConnectionFactory. spring.activemq.pool.expiry-timeout=0 # Connection expiration timeout in milliseconds. spring.activemq.pool.idle-timeout=30000 # Connection idle timeout in milliseconds. spring.activemq.pool.max-connections=1 # Maximum number of pooled connections. # ARTEMIS (ArtemisProperties) spring.artemis.embedded.cluster-password= # Cluster password. Randomly generated on startup by default. spring.artemis.embedded.data-directory= # Journal file directory. Not necessary if persistence is turned off. spring.artemis.embedded.enabled=true # Enable embedded mode if the Artemis server APIs are available. spring.artemis.embedded.persistent=false # Enable persistent store. spring.artemis.embedded.queues= # Comma-separated list of queues to create on startup. spring.artemis.embedded.server-id= # Server id. By default, an auto-incremented counter is used. spring.artemis.embedded.topics= # Comma-separated list of topics to create on startup. spring.artemis.host=localhost # Artemis broker host. spring.artemis.mode= # Artemis deployment mode, auto-detected by default. Can be explicitly set to "native" or "embedded". spring.artemis.port=61616 # Artemis broker port. # SPRING BATCH (BatchProperties) spring.batch.initializer.enabled=true # Create the required batch tables on startup if necessary. spring.batch.job.enabled=true # Execute all Spring Batch jobs in the context on startup. spring.batch.job.names= # Comma-separated list of job names to execute on startup (For instance `job1,job2`). By default, all Jobs found in the context are executed. spring.batch.schema=classpath:org/springframework/batch/core/schema-@@platform@@.sql # Path to the SQL file to use to initialize the database schema. spring.batch.table-prefix= # Table prefix for all the batch meta-data tables. # HORNETQ (HornetQProperties) spring.hornetq.embedded.cluster-password= # Cluster password. Randomly generated on startup by default. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 277 spring.hornetq.embedded.data-directory= # Journal file directory. Not necessary if persistence is turned off. spring.hornetq.embedded.enabled=true # Enable embedded mode if the HornetQ server APIs are available. spring.hornetq.embedded.persistent=false # Enable persistent store. spring.hornetq.embedded.queues= # Comma-separated list of queues to create on startup. spring.hornetq.embedded.server-id= # Server id. By default, an auto-incremented counter is used. spring.hornetq.embedded.topics= # Comma-separated list of topics to create on startup. spring.hornetq.host=localhost # HornetQ broker host. spring.hornetq.mode= # HornetQ deployment mode, auto-detected by default. Can be explicitly set to "native" or "embedded". spring.hornetq.port=5445 # HornetQ broker port. # JMS (JmsProperties) spring.jms.jndi-name= # Connection factory JNDI name. When set, takes precedence to others connection factory auto-configurations. spring.jms.listener.acknowledge-mode= # Acknowledge mode of the container. By default, the listener is transacted with automatic acknowledgment. spring.jms.listener.auto-startup=true # Start the container automatically on startup. spring.jms.listener.concurrency= # Minimum number of concurrent consumers. spring.jms.listener.max-concurrency= # Maximum number of concurrent consumers. spring.jms.pub-sub-domain=false # Specify if the default destination type is topic. # RABBIT (RabbitProperties) spring.rabbitmq.addresses= # Comma-separated list of addresses to which the client should connect. spring.rabbitmq.cache.channel.checkout-timeout= # Number of milliseconds to wait to obtain a channel if the cache size has been reached. spring.rabbitmq.cache.channel.size= # Number of channels to retain in the cache. spring.rabbitmq.cache.connection.mode=CHANNEL # Connection factory cache mode. spring.rabbitmq.cache.connection.size= # Number of connections to cache. spring.rabbitmq.connection-timeout= # Connection timeout, in milliseconds; zero for infinite. spring.rabbitmq.dynamic=true # Create an AmqpAdmin bean. spring.rabbitmq.host=localhost # RabbitMQ host. spring.rabbitmq.listener.acknowledge-mode= # Acknowledge mode of container. spring.rabbitmq.listener.auto-startup=true # Start the container automatically on startup. spring.rabbitmq.listener.concurrency= # Minimum number of consumers. spring.rabbitmq.listener.default-requeue-rejected= # Whether or not to requeue delivery failures; default `true`. spring.rabbitmq.listener.max-concurrency= # Maximum number of consumers. spring.rabbitmq.listener.prefetch= # Number of messages to be handled in a single request. It should be greater than or equal to the transaction size (if used). spring.rabbitmq.listener.retry.enabled=false # Whether or not publishing retries are enabled. spring.rabbitmq.listener.retry.initial-interval=1000 # Interval between the first and second attempt to deliver a message. spring.rabbitmq.listener.retry.max-attempts=3 # Maximum number of attempts to deliver a message. spring.rabbitmq.listener.retry.max-interval=10000 # Maximum number of attempts to deliver a message. spring.rabbitmq.listener.retry.multiplier=1.0 # A multiplier to apply to the previous delivery retry interval. spring.rabbitmq.listener.retry.stateless=true # Whether or not retry is stateless or stateful. spring.rabbitmq.listener.transaction-size= # Number of messages to be processed in a transaction. For best results it should be less than or equal to the prefetch count. spring.rabbitmq.password= # Login to authenticate against the broker. spring.rabbitmq.port=5672 # RabbitMQ port. spring.rabbitmq.publisher-confirms=false # Enable publisher confirms. spring.rabbitmq.publisher-returns=false # Enable publisher returns. spring.rabbitmq.requested-heartbeat= # Requested heartbeat timeout, in seconds; zero for none. spring.rabbitmq.ssl.enabled=false # Enable SSL support. spring.rabbitmq.ssl.key-store= # Path to the key store that holds the SSL certificate. spring.rabbitmq.ssl.key-store-password= # Password used to access the key store. spring.rabbitmq.ssl.trust-store= # Trust store that holds SSL certificates. spring.rabbitmq.ssl.trust-store-password= # Password used to access the trust store. spring.rabbitmq.ssl.algorithm= # SSL algorithm to use. By default configure by the rabbit client library. spring.rabbitmq.template.mandatory=false # Enable mandatory messages. spring.rabbitmq.template.receive-timeout=0 # Timeout for `receive()` methods. spring.rabbitmq.template.reply-timeout=5000 # Timeout for `sendAndReceive()` methods. spring.rabbitmq.template.retry.enabled=false # Set to true to enable retries in the `RabbitTemplate`. spring.rabbitmq.template.retry.initial-interval=1000 # Interval between the first and second attempt to publish a message. spring.rabbitmq.template.retry.max-attempts=3 # Maximum number of attempts to publish a message. spring.rabbitmq.template.retry.max-interval=10000 # Maximum number of attempts to publish a message. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 278 spring.rabbitmq.template.retry.multiplier=1.0 # A multiplier to apply to the previous publishing retry interval. spring.rabbitmq.username= # Login user to authenticate to the broker. spring.rabbitmq.virtual-host= # Virtual host to use when connecting to the broker. # ---------------------------------------- # ACTUATOR PROPERTIES # ---------------------------------------- # ENDPOINTS (AbstractEndpoint subclasses) endpoints.enabled=true # Enable endpoints. endpoints.sensitive= # Default endpoint sensitive setting. endpoints.actuator.enabled=true # Enable the endpoint. endpoints.actuator.path= # Endpoint URL path. endpoints.actuator.sensitive=false # Enable security on the endpoint. endpoints.autoconfig.enabled= # Enable the endpoint. endpoints.autoconfig.id= # Endpoint identifier. endpoints.autoconfig.path= # Endpoint path. endpoints.autoconfig.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.beans.enabled= # Enable the endpoint. endpoints.beans.id= # Endpoint identifier. endpoints.beans.path= # Endpoint path. endpoints.beans.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.configprops.enabled= # Enable the endpoint. endpoints.configprops.id= # Endpoint identifier. endpoints.configprops.keys-to-sanitize=password,secret,key,token,.*credentials.*,vcap_services # Keys that should be sanitized. Keys can be simple strings that the property ends with or regex expressions. endpoints.configprops.path= # Endpoint path. endpoints.configprops.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.docs.curies.enabled=false # Enable the curie generation. endpoints.docs.enabled=true # Enable actuator docs endpoint. endpoints.docs.path=/docs # endpoints.docs.sensitive=false # endpoints.dump.enabled= # Enable the endpoint. endpoints.dump.id= # Endpoint identifier. endpoints.dump.path= # Endpoint path. endpoints.dump.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.env.enabled= # Enable the endpoint. endpoints.env.id= # Endpoint identifier. endpoints.env.keys-to-sanitize=password,secret,key,token,.*credentials.*,vcap_services # Keys that should be sanitized. Keys can be simple strings that the property ends with or regex expressions. endpoints.env.path= # Endpoint path. endpoints.env.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.flyway.enabled= # Enable the endpoint. endpoints.flyway.id= # Endpoint identifier. endpoints.flyway.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.health.enabled= # Enable the endpoint. endpoints.health.id= # Endpoint identifier. endpoints.health.mapping.*= # Mapping of health statuses to HttpStatus codes. By default, registered health statuses map to sensible defaults (i.e. UP maps to 200). endpoints.health.path= # Endpoint path. endpoints.health.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.health.time-to-live=1000 # Time to live for cached result, in milliseconds. endpoints.info.enabled= # Enable the endpoint. endpoints.info.id= # Endpoint identifier. endpoints.info.path= # Endpoint path. endpoints.info.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.jolokia.enabled=true # Enable Jolokia endpoint. endpoints.jolokia.path=/jolokia # Endpoint URL path. endpoints.jolokia.sensitive=true # Enable security on the endpoint. endpoints.liquibase.enabled= # Enable the endpoint. endpoints.liquibase.id= # Endpoint identifier. endpoints.liquibase.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.logfile.enabled=true # Enable the endpoint. endpoints.logfile.path=/logfile # Endpoint URL path. endpoints.logfile.sensitive=true # Enable security on the endpoint. endpoints.mappings.enabled= # Enable the endpoint. endpoints.mappings.id= # Endpoint identifier. endpoints.mappings.path= # Endpoint path. endpoints.mappings.sensitive= # Mark if the endpoint exposes sensitive information. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 279 endpoints.metrics.enabled= # Enable the endpoint. endpoints.metrics.filter.enabled=true # Enable the metrics servlet filter. endpoints.metrics.filter.gauge-submissions=merged # Http filter gauge submissions (merged, per-http- method) endpoints.metrics.filter.counter-submissions=merged # Http filter counter submissions (merged, per-http- method) endpoints.metrics.id= # Endpoint identifier. endpoints.metrics.path= # Endpoint path. endpoints.metrics.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.shutdown.enabled= # Enable the endpoint. endpoints.shutdown.id= # Endpoint identifier. endpoints.shutdown.path= # Endpoint path. endpoints.shutdown.sensitive= # Mark if the endpoint exposes sensitive information. endpoints.trace.enabled= # Enable the endpoint. endpoints.trace.id= # Endpoint identifier. endpoints.trace.path= # Endpoint path. endpoints.trace.sensitive= # Mark if the endpoint exposes sensitive information. # ENDPOINTS CORS CONFIGURATION (EndpointCorsProperties) endpoints.cors.allow-credentials= # Set whether credentials are supported. When not set, credentials are not supported. endpoints.cors.allowed-headers= # Comma-separated list of headers to allow in a request. '*' allows all headers. endpoints.cors.allowed-methods=GET # Comma-separated list of methods to allow. '*' allows all methods. endpoints.cors.allowed-origins= # Comma-separated list of origins to allow. '*' allows all origins. When not set, CORS support is disabled. endpoints.cors.exposed-headers= # Comma-separated list of headers to include in a response. endpoints.cors.max-age=1800 # How long, in seconds, the response from a pre-flight request can be cached by clients. # JMX ENDPOINT (EndpointMBeanExportProperties) endpoints.jmx.domain= # JMX domain name. Initialized with the value of 'spring.jmx.default-domain' if set. endpoints.jmx.enabled=true # Enable JMX export of all endpoints. endpoints.jmx.static-names= # Additional static properties to append to all ObjectNames of MBeans representing Endpoints. endpoints.jmx.unique-names=false # Ensure that ObjectNames are modified in case of conflict. # JOLOKIA (JolokiaProperties) jolokia.config.*= # See Jolokia manual # MANAGEMENT HTTP SERVER (ManagementServerProperties) management.add-application-context-header=true # Add the "X-Application-Context" HTTP header in each response. management.address= # Network address that the management endpoints should bind to. management.context-path= # Management endpoint context-path. For instance `/actuator` management.port= # Management endpoint HTTP port. Use the same port as the application by default. management.security.enabled=true # Enable security. management.security.roles=ADMIN # Comma-separated list of roles that can access the management endpoint. management.security.sessions=stateless # Session creating policy to use (always, never, if_required, stateless). # HEALTH INDICATORS (previously health.*) management.health.db.enabled=true # Enable database health check. management.health.defaults.enabled=true # Enable default health indicators. management.health.diskspace.enabled=true # Enable disk space health check. management.health.diskspace.path= # Path used to compute the available disk space. management.health.diskspace.threshold=0 # Minimum disk space that should be available, in bytes. management.health.elasticsearch.enabled=true # Enable elasticsearch health check. management.health.elasticsearch.indices= # Comma-separated index names. management.health.elasticsearch.response-timeout=100 # The time, in milliseconds, to wait for a response from the cluster. management.health.jms.enabled=true # Enable JMS health check. management.health.mail.enabled=true # Enable Mail health check. management.health.mongo.enabled=true # Enable MongoDB health check. management.health.rabbit.enabled=true # Enable RabbitMQ health check. management.health.redis.enabled=true # Enable Redis health check. management.health.solr.enabled=true # Enable Solr health check. management.health.status.order=DOWN, OUT_OF_SERVICE, UNKNOWN, UP # Comma-separated list of health statuses in order of severity. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 280 # INFO CONTRIBUTORS (InfoContributorProperties) management.info.build.enabled=true # Enable build info. management.info.defaults.enabled=true # Enable default info contributors. management.info.env.enabled=true # Enable environment info. management.info.git.enabled=true # Enable git info. management.info.git.mode=simple # Mode to use to expose git information. # REMOTE SHELL (ShellProperties) management.shell.auth.type=simple # Authentication type. Auto-detected according to the environment. management.shell.auth.jaas.domain=my-domain # JAAS domain. management.shell.auth.key.path= # Path to the authentication key. This should point to a valid ".pem" file. management.shell.auth.simple.user.name=user # Login user. management.shell.auth.simple.user.password= # Login password. management.shell.auth.spring.roles=ADMIN # Comma-separated list of required roles to login to the CRaSH console. management.shell.command-path-patterns=classpath*:/commands/**,classpath*:/crash/commands/** # Patterns to use to look for commands. management.shell.command-refresh-interval=-1 # Scan for changes and update the command if necessary (in seconds). management.shell.config-path-patterns=classpath*:/crash/* # Patterns to use to look for configurations. management.shell.disabled-commands=jpa*,jdbc*,jndi* # Comma-separated list of commands to disable. management.shell.disabled-plugins= # Comma-separated list of plugins to disable. Certain plugins are disabled by default based on the environment. management.shell.ssh.auth-timeout = # Number of milliseconds after user will be prompted to login again. management.shell.ssh.enabled=true # Enable CRaSH SSH support. management.shell.ssh.idle-timeout = # Number of milliseconds after which unused connections are closed. management.shell.ssh.key-path= # Path to the SSH server key. management.shell.ssh.port=2000 # SSH port. management.shell.telnet.enabled=false # Enable CRaSH telnet support. Enabled by default if the TelnetPlugin is available. management.shell.telnet.port=5000 # Telnet port. # TRACING (TraceProperties) management.trace.include=request-headers,response-headers,errors # Items to be included in the trace. # METRICS EXPORT (MetricExportProperties) spring.metrics.export.aggregate.key-pattern= # Pattern that tells the aggregator what to do with the keys from the source repository. spring.metrics.export.aggregate.prefix= # Prefix for global repository if active. spring.metrics.export.delay-millis=5000 # Delay in milliseconds between export ticks. Metrics are exported to external sources on a schedule with this delay. spring.metrics.export.enabled=true # Flag to enable metric export (assuming a MetricWriter is available). spring.metrics.export.excludes= # List of patterns for metric names to exclude. Applied after the includes. spring.metrics.export.includes= # List of patterns for metric names to include. spring.metrics.export.redis.key=keys.spring.metrics # Key for redis repository export (if active). spring.metrics.export.redis.prefix=spring.metrics # Prefix for redis repository if active. spring.metrics.export.send-latest= # Flag to switch off any available optimizations based on not exporting unchanged metric values. spring.metrics.export.statsd.host= # Host of a statsd server to receive exported metrics. spring.metrics.export.statsd.port=8125 # Port of a statsd server to receive exported metrics. spring.metrics.export.statsd.prefix= # Prefix for statsd exported metrics. spring.metrics.export.triggers.*= # Specific trigger properties per MetricWriter bean name. # ---------------------------------------- # DEVTOOLS PROPERTIES # ---------------------------------------- # DEVTOOLS (DevToolsProperties) spring.devtools.livereload.enabled=true # Enable a livereload.com compatible server. spring.devtools.livereload.port=35729 # Server port. spring.devtools.restart.additional-exclude= # Additional patterns that should be excluded from triggering a full restart. spring.devtools.restart.additional-paths= # Additional paths to watch for changes. spring.devtools.restart.enabled=true # Enable automatic restart. spring.devtools.restart.exclude=META-INF/maven/**,META-INF/resources/**,resources/**,static/**,public/ **,templates/**,**/*Test.class,**/*Tests.class,git.properties # Patterns that should be excluded from triggering a full restart. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 281 spring.devtools.restart.poll-interval=1000 # Amount of time (in milliseconds) to wait between polling for classpath changes. spring.devtools.restart.quiet-period=400 # Amount of quiet time (in milliseconds) required without any classpath changes before a restart is triggered. spring.devtools.restart.trigger-file= # Name of a specific file that when changed will trigger the restart check. If not specified any classpath file change will trigger the restart. # REMOTE DEVTOOLS (RemoteDevToolsProperties) spring.devtools.remote.context-path=/.~~spring-boot!~ # Context path used to handle the remote connection. spring.devtools.remote.debug.enabled=true # Enable remote debug support. spring.devtools.remote.debug.local-port=8000 # Local remote debug server port. spring.devtools.remote.proxy.host= # The host of the proxy to use to connect to the remote application. spring.devtools.remote.proxy.port= # The port of the proxy to use to connect to the remote application. spring.devtools.remote.restart.enabled=true # Enable remote restart. spring.devtools.remote.secret= # A shared secret required to establish a connection (required to enable remote support). spring.devtools.remote.secret-header-name=X-AUTH-TOKEN # HTTP header used to transfer the shared secret. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 282 Appendix B. Configuration meta-data Spring Boot jars are shipped with meta-data files that provide details of all supported configuration properties. The files are designed to allow IDE developers to offer contextual help and “code completion” as users are working with application.properties or application.yml files. The majority of the meta-data file is generated automatically at compile time by processing all items annotated with @ConfigurationProperties. However, it is possible to write part of the meta-data manually for corner cases or more advanced use cases. B.1 Meta-data format Configuration meta-data files are located inside jars under META-INF/spring-configuration- metadata.json They use a simple JSON format with items categorized under either “groups” or “properties” and additional values hint categorized under "hints": {"groups": [ { "name": "server", "type": "org.springframework.boot.autoconfigure.web.ServerProperties", "sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties" }, { "name": "spring.jpa.hibernate", "type": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties$Hibernate", "sourceType": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties", "sourceMethod": "getHibernate()" } ... ],"properties": [ { "name": "server.port", "type": "java.lang.Integer", "sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties" }, { "name": "server.servlet-path", "type": "java.lang.String", "sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties", "defaultValue": "/" }, { "name": "spring.jpa.hibernate.ddl-auto", "type": "java.lang.String", "description": "DDL mode. This is actually a shortcut for the \"hibernate.hbm2ddl.auto\" property.", "sourceType": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties$Hibernate" } ... ],"hints": [ { "name": "spring.jpa.hibernate.ddl-auto", "values": [ { "value": "none", "description": "Disable DDL handling." }, { "value": "validate", "description": "Validate the schema, make no changes to the database." }, { "value": "update", "description": "Update the schema if necessary." Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 283 }, { "value": "create", "description": "Create the schema and destroy previous data." }, { "value": "create-drop", "description": "Create and then destroy the schema at the end of the session." } ] } ]} Each “property” is a configuration item that the user specifies with a given value. For example server.port and server.servlet-path might be specified in application.properties as follows: server.port=9090 server.servlet-path=/home The “groups” are higher level items that don’t themselves specify a value, but instead provide a contextual grouping for properties. For example the server.port and server.servlet-path properties are part of the server group. Note It is not required that every “property” has a “group”, some properties might just exist in their own right. Finally, “hints” are additional information used to assist the user in configuring a given property. When configuring the spring.jpa.hibernate.ddl-auto property, a tool can use it to offer some auto- completion help for the none, validate, update, create and create-drop values. Group Attributes The JSON object contained in the groups array can contain the following attributes: Name Type Purpose name String The full name of the group. This attribute is mandatory. type String The class name of the data type of the group. For example, if the group was based on a class annotated with @ConfigurationProperties the attribute would contain the fully qualified name of that class. If it was based on a @Bean method, it would be the return type of that method. The attribute may be omitted if the type is not known. description String A short description of the group that can be displayed to users. May be omitted if no description is available. It is recommended that descriptions are a short paragraphs, with the first line providing a concise summary. The last line in the description should end with a period (.). sourceType String The class name of the source that contributed this group. For example, if the group was based on a @Bean method annotated Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 284 Name Type Purpose with @ConfigurationProperties this attribute would contain the fully qualified name of the @Configuration class containing the method. The attribute may be omitted if the source type is not known. sourceMethod String The full name of the method (include parenthesis and argument types) that contributed this group. For example, the name of a @ConfigurationProperties annotated @Bean method. May be omitted if the source method is not known. Property Attributes The JSON object contained in the properties array can contain the following attributes: Name Type Purpose name String The full name of the property. Names are in lowercase dashed form (e.g. server.servlet-path). This attribute is mandatory. type String The class name of the data type of the property. For example, java.lang.String. This attribute can be used to guide the user as to the types of values that they can enter. For consistency, the type of a primitive is specified using its wrapper counterpart, i.e. boolean becomes java.lang.Boolean. Note that this class may be a complex type that gets converted from a String as values are bound. May be omitted if the type is not known. description String A short description of the group that can be displayed to users. May be omitted if no description is available. It is recommended that descriptions are a short paragraphs, with the first line providing a concise summary. The last line in the description should end with a period (.). sourceType String The class name of the source that contributed this property. For example, if the property was from a class annotated with @ConfigurationProperties this attribute would contain the fully qualified name of that class. May be omitted if the source type is not known. defaultValue Object The default value which will be used if the property is not specified. Can also be an array of value(s) if the type of the property is an array. May be omitted if the default value is not known. deprecation Deprecation Specify if the property is deprecated. May be omitted if the field is not deprecated or if that information is not known. See below for more details. The JSON object contained in the deprecation attribute of each properties element can contain the following attributes: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 285 Name Type Purpose reason String A short description of the reason why the property was deprecated. May be omitted if no reason is available. It is recommended that descriptions are a short paragraphs, with the first line providing a concise summary. The last line in the description should end with a period (.). replacement String The full name of the property that is replacing this deprecated property. May be omitted if there is no replacement for this property. Note Prior to Spring Boot 1.3, a single deprecated boolean attribute can be used instead of the deprecation element. This is still supported in a deprecated fashion and should no longer be used. If no reason and replacement are available, an empty deprecation object should be set. Deprecation can also be specified declaratively in code by adding the @DeprecatedConfigurationProperty annotation to the getter exposing the deprecated property. For instance, let’s assume the app.foo.target property was confusing and was renamed to app.foo.name @ConfigurationProperties("app.foo") public class FooProperties { private String name; public String getName() { ... } public void setName(String name) { ... } @DeprecatedConfigurationProperty(replacement = "app.foo.name") @Deprecated public String getTarget() { return getName(); } @Deprecated public void setTarget(String target) { setName(target); } } The code above makes sure that the deprecated property still works (delegating to the name property behind the scenes). Once the getTarget and setTarget methods can be removed from your public API, the automatic deprecation hint in the meta-data will go away as well. Hint Attributes The JSON object contained in the hints array can contain the following attributes: Name Type Purpose name String The full name of the property that this hint refers to. Names are in lowercase dashed form (e.g. server.servlet-path). If the property refers to a map (e.g. system.contexts) the hint either Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 286 Name Type Purpose applies to the keys of the map (system.context.keys) or the values (system.context.values). This attribute is mandatory. values ValueHint[] A list of valid values as defined by the ValueHint object (see below). Each entry defines the value and may have a description providers ValueProvider[] A list of providers as defined by the ValueProvider object (see below). Each entry defines the name of the provider and its parameters, if any. The JSON object contained in the values attribute of each hint element can contain the following attributes: Name Type Purpose value Object A valid value for the element to which the hint refers to. Can also be an array of value(s) if the type of the property is an array. This attribute is mandatory. description String A short description of the value that can be displayed to users. May be omitted if no description is available. It is recommended that descriptions are a short paragraphs, with the first line providing a concise summary. The last line in the description should end with a period (.). The JSON object contained in the providers attribute of each hint element can contain the following attributes: Name Type Purpose name String The name of the provider to use to offer additional content assistance for the element to which the hint refers to. parameters JSON object Any additional parameter that the provider supports (check the documentation of the provider for more details). Repeated meta-data items It is perfectly acceptable for “property” and “group” objects with the same name to appear multiple times within a meta-data file. For example, you could bind two separate classes to the same prefix, with each potentially offering overlap of property names. While this is not supposed to be a frequent scenario, consumers of meta-data should take care to ensure that they support such scenarios. B.2 Providing manual hints To improve the user experience and further assist the user in configuring a given property, you can provide additional meta-data that: 1. Describes the list of potential values for a property. 2. Associates a provider to attach a well-defined semantic to a property so that a tool can discover the list of potential values based on the project’s context. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 287 Value hint The name attribute of each hint refers to the name of a property. In the initial example above, we provide 5 values for the spring.jpa.hibernate.ddl-auto property: none, validate, update, create and create-drop. Each value may have a description as well. If your property is of type Map, you can provide hints for both the keys and the values (but not for the map itself). The special .keys and .values suffixes must be used to refer to the keys and the values respectively. Let’s assume a foo.contexts that maps magic String values to an integer: @ConfigurationProperties("foo") public class FooProperties { private Map contexts; // getters and setters } The magic values are foo and bar for instance. In order to offer additional content assistance for the keys, you could add the following to the manual meta-data of the module: {"hints": [ { "name": "foo.contexts.keys", "values": [ { "value": "foo" }, { "value": "bar" } ] } ]} Note Of course, you should have an Enum for those two values instead. This is by far the most effective approach to auto-completion if your IDE supports it. Value provider Providers are a powerful way of attaching semantics to a property. We define in the section below the official providers that you can use for your own hints. Bare in mind however that your favorite IDE may implement some of these or none of them. It could eventually provide its own as well. Note As this is a new feature, IDE vendors will have to catch up with this new feature. The table below summarizes the list of supported providers: Name Description any Permit any additional value to be provided. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 288 Name Description class-reference Auto-complete the classes available in the project. Usually constrained by a base class that is specified via the target parameter. handle-as Handle the property as if it was defined by the type defined via the mandatory target parameter. logger-name Auto-complete valid logger names. Typically, package and class names available in the current project can be auto-completed. spring-bean-reference Auto-complete the available bean names in the current project. Usually constrained by a base class that is specified via the target parameter. spring-profile-name Auto-complete the available Spring profile names in the project. Tip No more than one provider can be active for a given property but you can specify several providers if they can all manage the property in some ways. Make sure to place the most powerful provider first as the IDE must use the first one in the JSON section it can handle. If no provider for a given property is supported, no special content assistance is provided either. Any The any provider permits any additional values to be provided. Regular value validation based on the property type should be applied if this is supported. This provider will be typically used if you have a list of values and any extra values are still to be considered as valid. The example below offers on and off as auto-completion values for system.state; any other value is also allowed: {"hints": [ { "name": "system.state", "values": [ { "value": "on" }, { "value": "off" } ], "providers": [ { "name": "any" } ] } ]} Class reference The class-reference provider auto-completes classes available in the project. This provider supports these parameters: Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 289 Parameter Type Default value Description target String (Class) none The fully qualified name of the class that should be assignable to the chosen value. Typically used to filter out non candidate classes. Note that this information can be provided by the type itself by exposing a class with the appropriate upper bound. concrete boolean true Specify if only concrete classes are to be considered as valid candidates. The meta-data snippet below corresponds to the standard server.jsp-servlet.class-name property that defines the JspServlet class name to use: {"hints": [ { "name": "server.jsp-servlet.class-name", "providers": [ { "name": "class-reference", "parameters": { "target": "javax.servlet.http.HttpServlet" } } ] } ]} Handle As The handle-as provider allows you to substitute the type of the property to a more high-level type. This typically happens when the property has a java.lang.String type because you don’t want your configuration classes to rely on classes that may not be on the classpath. This provider supports these parameters: Parameter Type Default value Description target String (Class) none The fully qualified name of the type to consider for the property. This parameter is mandatory. The following types can be used: • Any java.lang.Enum that lists the possible values for the property (By all means, try to define the property with the Enum type instead as no further hint should be required for the IDE to auto-complete the values). • java.nio.charset.Charset: auto-completion of charset/encoding values (e.g. UTF-8) • java.util.Locale: auto-completion of locales (e.g. en_US) • org.springframework.util.MimeType: auto-completion of content type values (e.g. text/ plain) • org.springframework.core.io.Resource: auto-completion of Spring’s Resource abstraction to refer to a file on the filesystem or on the classpath. (e.g. classpath:/foo.properties) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 290 Note If multiple values can be provided, use a Collection or Array type to teach the IDE about it. The meta-data snippet below corresponds to the standard liquibase.change-log property that defines the path to the changelog to use. It is actually used internally as a org.springframework.core.io.Resource but cannot be exposed as such as we need to keep the original String value to pass it to the Liquibase API. {"hints": [ { "name": "liquibase.change-log", "providers": [ { "name": "handle-as", "parameters": { "target": "org.springframework.core.io.Resource" } } ] } ]} Logger name The logger-name provider auto-completes valid logger names. Typically, package and class names available in the current project can be auto-completed. Specific frameworks may have extra magic logger names that could be supported as well. Since a logger name can be any arbitrary name, really, this provider should allow any value but could highlight valid packages and class names that are not available in the project’s classpath. The meta-data snippet below corresponds to the standard logging.level property, keys are logger names and values correspond to the standard log levels or any custom level: {"hints": [ { "name": "logging.level.keys", "values": [ { "value": "root", "description": "Root logger used to assign the default logging level." } ], "providers": [ { "name": "logger-name" } ] }, { "name": "logging.level.values", "values": [ { "value": "trace" }, { "value": "debug" }, { "value": "info" }, { "value": "warn" }, Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 291 { "value": "error" }, { "value": "fatal" }, { "value": "off" } ], "providers": [ { "name": "any" } ] } ]} Spring bean reference The spring-bean-reference provider auto-completes the beans that are defined in the configuration of the current project. This provider supports these parameters: Parameter Type Default value Description target String (Class) none The fully qualified name of the bean class that should be assignable to the candidate. Typically used to filter out non candidate beans. The meta-data snippet below corresponds to the standard spring.jmx.server property that defines the name of the MBeanServer bean to use: {"hints": [ { "name": "spring.jmx.server", "providers": [ { "name": "spring-bean-reference", "parameters": { "target": "javax.management.MBeanServer" } } ] } ]} Note The binder is not aware of the meta-data so if you provide that hint, you will still need to transform the bean name into an actual Bean reference using the ApplicationContext. Spring profile name The spring-profile-name provider auto-completes the Spring profiles that are defined in the configuration of the current project. The meta-data snippet below corresponds to the standard spring.profiles.active property that defines the name of the Spring profile(s) to enable: {"hints": [ { Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 292 "name": "spring.profiles.active", "providers": [ { "name": "spring-profile-name" } ] } ]} B.3 Generating your own meta-data using the annotation processor You can easily generate your own configuration meta-data file from items annotated with @ConfigurationProperties by using the spring-boot-configuration-processor jar. The jar includes a Java annotation processor which is invoked as your project is compiled. To use the processor, simply include spring-boot-configuration-processor as an optional dependency, for example with Maven you would add: org.springframework.boot spring-boot-configuration-processor true With Gradle, you can use the propdeps-plugin and specify: dependencies { optional "org.springframework.boot:spring-boot-configuration-processor" } compileJava.dependsOn(processResources) } Note You need to add compileJava.dependsOn(processResources) to your build to ensure that resources are processed before code is compiled. Without this directive any additional- spring-configuration-metadata.json files will not be processed. The processor will pick up both classes and methods that are annotated with @ConfigurationProperties. The Javadoc for field values within configuration classes will be used to populate the description attribute. Note You should only use simple text with @ConfigurationProperties field Javadoc since they are not processed before being added to the JSON. Properties are discovered via the presence of standard getters and setters with special handling for collection types (that will be detected even if only a getter is present). The annotation processor also supports the use of the @Data, @Getter and @Setter lombok annotations. Note If you are using AspectJ in your project, you need to make sure that the annotation processor only runs once. There are several ways to do this: with Maven, you can configure the maven-apt- Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 293 plugin explicitly and add the dependency to the annotation processor only there. You could also let the AspectJ plugin run all the processing and disable annotation processing in the maven- compiler-plugin configuration: org.apache.maven.plugins maven-compiler-plugin none Nested properties The annotation processor will automatically consider inner classes as nested properties. For example, the following class: @ConfigurationProperties(prefix="server") public class ServerProperties { private String name; private Host host; // ... getter and setters private static class Host { private String ip; private int port; // ... getter and setters } } Will produce meta-data information for server.name, server.host.ip and server.host.port properties. You can use the @NestedConfigurationProperty annotation on a field to indicate that a regular (non-inner) class should be treated as if it were nested. Adding additional meta-data Spring Boot’s configuration file handling is quite flexible; and it is often the case that properties may exist that are not bound to a @ConfigurationProperties bean. You may also need to tune some attributes of an existing key. To support such cases and allow you to provide custom "hints", the annotation processor will automatically merge items from META-INF/additional-spring- configuration-metadata.json into the main meta-data file. If you refer to a property that has been detected automatically, the description, default value and deprecation information are overridden if specified. If the manual property declaration is not identified in the current module, it is added as a brand new property. The format of the additional-spring-configuration-metadata.json file is exactly the same as the regular spring-configuration-metadata.json. The additional properties file is optional, if you don’t have any additional properties, simply don’t add it. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 294 Appendix C. Auto-configuration classes Here is a list of all auto-configuration classes provided by Spring Boot with links to documentation and source code. Remember to also look at the autoconfig report in your application for more details of which features are switched on. (start the app with --debug or -Ddebug, or in an Actuator application use the autoconfig endpoint). C.1 From the “spring-boot-autoconfigure” module The following auto-configuration classes are from the spring-boot-autoconfigure module: Configuration Class Links ActiveMQAutoConfiguration javadoc AopAutoConfiguration javadoc ArtemisAutoConfiguration javadoc BatchAutoConfiguration javadoc CacheAutoConfiguration javadoc CassandraAutoConfiguration javadoc CassandraDataAutoConfiguration javadoc CassandraRepositoriesAutoConfiguration javadoc CloudAutoConfiguration javadoc ConfigurationPropertiesAutoConfiguration javadoc CouchbaseAutoConfiguration javadoc CouchbaseDataAutoConfiguration javadoc CouchbaseRepositoriesAutoConfiguration javadoc DataSourceAutoConfiguration javadoc DataSourceTransactionManagerAutoConfiguration javadoc DeviceDelegatingViewResolverAutoConfiguration javadoc DeviceResolverAutoConfiguration javadoc DispatcherServletAutoConfiguration javadoc ElasticsearchAutoConfiguration javadoc ElasticsearchDataAutoConfiguration javadoc ElasticsearchRepositoriesAutoConfiguration javadoc EmbeddedMongoAutoConfiguration javadoc Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 295 Configuration Class Links EmbeddedServletContainerAutoConfiguration javadoc ErrorMvcAutoConfiguration javadoc FacebookAutoConfiguration javadoc FallbackWebSecurityAutoConfiguration javadoc FlywayAutoConfiguration javadoc FreeMarkerAutoConfiguration javadoc GroovyTemplateAutoConfiguration javadoc GsonAutoConfiguration javadoc H2ConsoleAutoConfiguration javadoc HazelcastAutoConfiguration javadoc HazelcastJpaDependencyAutoConfiguration javadoc HibernateJpaAutoConfiguration javadoc HornetQAutoConfiguration javadoc HttpEncodingAutoConfiguration javadoc HttpMessageConvertersAutoConfiguration javadoc HypermediaAutoConfiguration javadoc IntegrationAutoConfiguration javadoc JacksonAutoConfiguration javadoc JerseyAutoConfiguration javadoc JmsAutoConfiguration javadoc JmxAutoConfiguration javadoc JndiConnectionFactoryAutoConfiguration javadoc JndiDataSourceAutoConfiguration javadoc JooqAutoConfiguration javadoc JpaRepositoriesAutoConfiguration javadoc JtaAutoConfiguration javadoc LinkedInAutoConfiguration javadoc LiquibaseAutoConfiguration javadoc MailSenderAutoConfiguration javadoc MailSenderValidatorAutoConfiguration javadoc Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 296 Configuration Class Links MessageSourceAutoConfiguration javadoc MongoAutoConfiguration javadoc MongoDataAutoConfiguration javadoc MongoRepositoriesAutoConfiguration javadoc MultipartAutoConfiguration javadoc MustacheAutoConfiguration javadoc Neo4jAutoConfiguration javadoc Neo4jRepositoriesAutoConfiguration javadoc OAuth2AutoConfiguration javadoc PersistenceExceptionTranslationAutoConfiguration javadoc ProjectInfoAutoConfiguration javadoc PropertyPlaceholderAutoConfiguration javadoc RabbitAutoConfiguration javadoc ReactorAutoConfiguration javadoc RedisAutoConfiguration javadoc RedisRepositoriesAutoConfiguration javadoc RepositoryRestMvcAutoConfiguration javadoc SecurityAutoConfiguration javadoc SecurityFilterAutoConfiguration javadoc SendGridAutoConfiguration javadoc ServerPropertiesAutoConfiguration javadoc SessionAutoConfiguration javadoc SitePreferenceAutoConfiguration javadoc SocialWebAutoConfiguration javadoc SolrAutoConfiguration javadoc SolrRepositoriesAutoConfiguration javadoc SpringApplicationAdminJmxAutoConfiguration javadoc SpringDataWebAutoConfiguration javadoc ThymeleafAutoConfiguration javadoc TransactionAutoConfiguration javadoc Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 297 Configuration Class Links TwitterAutoConfiguration javadoc VelocityAutoConfiguration javadoc WebClientAutoConfiguration javadoc WebMvcAutoConfiguration javadoc WebServicesAutoConfiguration javadoc WebSocketAutoConfiguration javadoc WebSocketMessagingAutoConfiguration javadoc XADataSourceAutoConfiguration javadoc C.2 From the “spring-boot-actuator” module The following auto-configuration classes are from the spring-boot-actuator module: Configuration Class Links AuditAutoConfiguration javadoc CacheStatisticsAutoConfiguration javadoc CrshAutoConfiguration javadoc EndpointAutoConfiguration javadoc EndpointMBeanExportAutoConfiguration javadoc EndpointWebMvcAutoConfiguration javadoc HealthIndicatorAutoConfiguration javadoc InfoContributorAutoConfiguration javadoc JolokiaAutoConfiguration javadoc ManagementServerPropertiesAutoConfiguration javadoc ManagementWebSecurityAutoConfiguration javadoc MetricExportAutoConfiguration javadoc MetricFilterAutoConfiguration javadoc MetricRepositoryAutoConfiguration javadoc MetricsChannelAutoConfiguration javadoc MetricsDropwizardAutoConfiguration javadoc PublicMetricsAutoConfiguration javadoc TraceRepositoryAutoConfiguration javadoc TraceWebFilterAutoConfiguration javadoc Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 298 Appendix D. The executable jar format The spring-boot-loader modules allows Spring Boot to support executable jar and war files. If you’re using the Maven or Gradle plugin, executable jars are automatically generated and you generally won’t need to know the details of how they work. If you need to create executable jars from a different build system, or if you are just curious about the underlying technology, this section provides some background. D.1 Nested JARs Java does not provide any standard way to load nested jar files (i.e. jar files that are themselves contained within a jar). This can be problematic if you are looking to distribute a self-contained application that you can just run from the command line without unpacking. To solve this problem, many developers use “shaded” jars. A shaded jar simply packages all classes, from all jars, into a single 'uber jar'. The problem with shaded jars is that it becomes hard to see which libraries you are actually using in your application. It can also be problematic if the same filename is used (but with different content) in multiple jars. Spring Boot takes a different approach and allows you to actually nest jars directly. The executable jar file structure Spring Boot Loader compatible jar files should be structured in the following way: example.jar | +-META-INF | +-MANIFEST.MF +-org | +-springframework | +-boot | +-loader | +- +-BOOT-INF +-classes | +-mycompany | +-project | +-YourClasses.class +-lib +-dependency1.jar +-dependency2.jar Application classes should be placed in a nested BOOT-INF/classes directory. Dependencies should be placed in a nested BOOT-INF/lib directory. The executable war file structure Spring Boot Loader compatible war files should be structured in the following way: example.war | +-META-INF | +-MANIFEST.MF +-org Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 299 | +-springframework | +-boot | +-loader | +- +-WEB-INF +-classes | +-com | +-mycompany | +-project | +-YourClasses.class +-lib | +-dependency1.jar | +-dependency2.jar +-lib-provided +-servlet-api.jar +-dependency3.jar Dependencies should be placed in a nested WEB-INF/lib directory. Any dependencies that are required when running embedded but are not required when deploying to a traditional web container should be placed in WEB-INF/lib-provided. D.2 Spring Boot’s “JarFile” class The core class used to support loading nested jars is org.springframework.boot.loader.jar.JarFile. It allows you to load jar content from a standard jar file, or from nested child jar data. When first loaded, the location of each JarEntry is mapped to a physical file offset of the outer jar: myapp.jar +-------------------+-------------------------+ | /BOOT-INF/classes | /BOOT-INF/lib/mylib.jar | |+-----------------+||+-----------+----------+| || A.class ||| B.class | C.class || |+-----------------+||+-----------+----------+| +-------------------+-------------------------+ ^ ^ ^ 0063 3452 3980 The example above shows how A.class can be found in /BOOT-INF/classes in myapp.jar position 0063. B.class from the nested jar can actually be found in myapp.jar position 3452 and C.class is at position 3980. Armed with this information, we can load specific nested entries by simply seeking to the appropriate part of the outer jar. We don’t need to unpack the archive and we don’t need to read all entry data into memory. Compatibility with the standard Java “JarFile” Spring Boot Loader strives to remain compatible with existing code and libraries. org.springframework.boot.loader.jar.JarFile extends from java.util.jar.JarFile and should work as a drop-in replacement. The getURL() method will return a URL that opens a java.net.JarURLConnection compatible connection and can be used with Java’s URLClassLoader. D.3 Launching executable jars The org.springframework.boot.loader.Launcher class is a special bootstrap class that is used as an executable jars main entry point. It is the actual Main-Class in your jar file and it’s used to setup an appropriate URLClassLoader and ultimately call your main() method. Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 300 There are 3 launcher subclasses (JarLauncher, WarLauncher and PropertiesLauncher). Their purpose is to load resources (.class files etc.) from nested jar files or war files in directories (as opposed to explicitly on the classpath). In the case of JarLauncher and WarLauncher the nested paths are fixed. JarLauncher looks in BOOT-INF/lib/ and WarLauncher looks in WEB-INF/ lib/ and WEB-INF/lib-provided/ so you just add extra jars in those locations if you want more. The PropertiesLauncher looks in BOOT-INF/lib/ in your application archive by default, but you can add additional locations by setting an environment variable LOADER_PATH or loader.path in application.properties (comma-separated list of directories or archives). Launcher manifest You need to specify an appropriate Launcher as the Main-Class attribute of META-INF/ MANIFEST.MF. The actual class that you want to launch (i.e. the class that you wrote that contains a main method) should be specified in the Start-Class attribute. For example, here is a typical MANIFEST.MF for an executable jar file: Main-Class: org.springframework.boot.loader.JarLauncher Start-Class: com.mycompany.project.MyApplication For a war file, it would be: Main-Class: org.springframework.boot.loader.WarLauncher Start-Class: com.mycompany.project.MyApplication Note You do not need to specify Class-Path entries in your manifest file, the classpath will be deduced from the nested jars. Exploded archives Certain PaaS implementations may choose to unpack archives before they run. For example, Cloud Foundry operates in this way. You can run an unpacked archive by simply starting the appropriate launcher: $ unzip -q myapp.jar $ java org.springframework.boot.loader.JarLauncher D.4 PropertiesLauncher Features PropertiesLauncher has a few special features that can be enabled with external properties (System properties, environment variables, manifest entries or application.properties). Key Purpose loader.path Comma-separated Classpath, e.g. lib,${HOME}/app/lib. Earlier entries take precedence, just like a regular -classpath on the javac command line. loader.home Location of additional properties file, e.g. /opt/app (defaults to ${user.dir}) loader.args Default arguments for the main method (space separated) Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 301 Key Purpose loader.main Name of main class to launch, e.g. com.app.Application. loader.config.name Name of properties file, e.g. loader (defaults to application). loader.config.location Path to properties file, e.g. classpath:loader.properties (defaults to application.properties). loader.system Boolean flag to indicate that all properties should be added to System properties (defaults to false) Manifest entry keys are formed by capitalizing initial letters of words and changing the separator to “-” from “.” (e.g. Loader-Path). The exception is loader.main which is looked up as Start-Class in the manifest for compatibility with JarLauncher). Tip Build plugins automatically move the Main-Class attribute to Start-Class when the fat jar is built. If you are using that, specify the name of the class to launch using the Main-Class attribute and leave out Start-Class. Environment variables can be capitalized with underscore separators instead of periods. • loader.home is the directory location of an additional properties file (overriding the default) as long as loader.config.location is not specified. • loader.path can contain directories (scanned recursively for jar and zip files), archive paths, or wildcard patterns (for the default JVM behavior). • loader.path (if empty) defaults to lib (meaning a local directory or a nested one if running from an archive). Because of this PropertiesLauncher behaves the same as JarLauncher when no additional configuration is provided. • Placeholder replacement is done from System and environment variables plus the properties file itself on all values before use. D.5 Executable jar restrictions There are a number of restrictions that you need to consider when working with a Spring Boot Loader packaged application. Zip entry compression The ZipEntry for a nested jar must be saved using the ZipEntry.STORED method. This is required so that we can seek directly to individual content within the nested jar. The content of the nested jar file itself can still be compressed, as can any other entries in the outer jar. System ClassLoader Launched applications should use Thread.getContextClassLoader() when loading classes (most libraries and frameworks will do this by default). Trying to load nested jar classes via ClassLoader.getSystemClassLoader() will fail. Please be aware that java.util.Logging Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 302 always uses the system classloader, for this reason you should consider a different logging implementation. D.6 Alternative single jar solutions If the above restrictions mean that you cannot use Spring Boot Loader the following alternatives could be considered: • Maven Shade Plugin • JarClassLoader • OneJar Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 303 Appendix E. Dependency versions The table below provides details of all of the dependency versions that are provided by Spring Boot in its CLI, Maven dependency management and Gradle plugin. When you declare a dependency on one of these artifacts without declaring a version the version that is listed in the table will be used. Group ID Artifact ID Version antlr antlr 2.7.7 ch.qos.logback logback-access 1.1.7 ch.qos.logback logback-classic 1.1.7 ch.qos.logback logback-core 1.1.7 com.atomikos transactions-jdbc 3.9.3 com.atomikos transactions-jms 3.9.3 com.atomikos transactions-jta 3.9.3 com.couchbase.client couchbase-spring-cache 2.0.0 com.couchbase.client java-client 2.2.7 com.datastax.cassandra cassandra-driver-core 2.1.9 com.datastax.cassandra cassandra-driver-dse 2.1.9 com.datastax.cassandra cassandra-driver- mapping 2.1.9 com.fasterxml classmate 1.3.1 com.fasterxml.jackson.corejackson-annotations 2.7.4 com.fasterxml.jackson.corejackson-core 2.7.4 com.fasterxml.jackson.corejackson-databind 2.7.4 com.fasterxml.jackson.dataformatjackson-dataformat-cbor 2.7.4 com.fasterxml.jackson.dataformatjackson-dataformat-csv 2.7.4 com.fasterxml.jackson.dataformatjackson-dataformat- smile 2.7.4 com.fasterxml.jackson.dataformatjackson-dataformat-xml 2.7.4 com.fasterxml.jackson.dataformatjackson-dataformat-yaml 2.7.4 com.fasterxml.jackson.datatypejackson-datatype-guava 2.7.4 com.fasterxml.jackson.datatypejackson-datatype- hibernate4 2.7.4 com.fasterxml.jackson.datatypejackson-datatype- hibernate5 2.7.4 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 304 Group ID Artifact ID Version com.fasterxml.jackson.datatypejackson-datatype-jdk8 2.7.4 com.fasterxml.jackson.datatypejackson-datatype-joda 2.7.4 com.fasterxml.jackson.datatypejackson-datatype-json- org 2.7.4 com.fasterxml.jackson.datatypejackson-datatype-jsr310 2.7.4 com.fasterxml.jackson.jaxrsjackson-jaxrs-base 2.7.4 com.fasterxml.jackson.jaxrsjackson-jaxrs-json- provider 2.7.4 com.fasterxml.jackson.modulejackson-module-jaxb- annotations 2.7.4 com.fasterxml.jackson.modulejackson-module-kotlin 2.7.4 com.fasterxml.jackson.modulejackson-module- parameter-names 2.7.4 com.gemstone.gemfire gemfire 8.2.0 com.github.ben- manes.caffeine caffeine 2.3.0 com.github.mxab.thymeleaf.extrasthymeleaf-extras-data- attribute 1.3 com.google.appengine appengine-api-1.0-sdk 1.9.38 com.google.code.gson gson 2.6.2 com.googlecode.json- simple json-simple 1.1.1 com.h2database h2 1.4.192 com.hazelcast hazelcast 3.6.3 com.hazelcast hazelcast-hibernate4 3.6.3 com.hazelcast hazelcast-spring 3.6.3 com.jayway.jsonpath json-path 2.2.0 com.jayway.jsonpath json-path-assert 2.2.0 com.samskivert jmustache 1.12 com.sendgrid sendgrid-java 2.2.2 com.sun.mail javax.mail 1.5.5 com.timgroup java-statsd-client 3.1.0 com.zaxxer HikariCP 2.4.6 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 305 Group ID Artifact ID Version com.zaxxer HikariCP-java6 2.3.13 commons-beanutils commons-beanutils 1.9.2 commons-codec commons-codec 1.10 commons-collections commons-collections 3.2.2 commons-dbcp commons-dbcp 1.4 commons-digester commons-digester 2.1 commons-pool commons-pool 1.6 de.flapdoodle.embed de.flapdoodle.embed.mongo1.50.5 dom4j dom4j 1.6.1 io.dropwizard.metrics metrics-core 3.1.2 io.dropwizard.metrics metrics-ganglia 3.1.2 io.dropwizard.metrics metrics-graphite 3.1.2 io.dropwizard.metrics metrics-servlets 3.1.2 io.projectreactor reactor-bus 2.0.8.RELEASE io.projectreactor reactor-core 2.0.8.RELEASE io.projectreactor reactor-groovy 2.0.8.RELEASE io.projectreactor reactor-groovy- extensions 2.0.8.RELEASE io.projectreactor reactor-logback 2.0.8.RELEASE io.projectreactor reactor-net 2.0.8.RELEASE io.projectreactor reactor-stream 2.0.8.RELEASE io.projectreactor.spring reactor-spring-context 2.0.7.RELEASE io.projectreactor.spring reactor-spring-core 2.0.7.RELEASE io.projectreactor.spring reactor-spring- messaging 2.0.7.RELEASE io.projectreactor.spring reactor-spring-webmvc 2.0.7.RELEASE io.undertow undertow-core 1.3.22.Final io.undertow undertow-servlet 1.3.22.Final io.undertow undertow-websockets-jsr 1.3.22.Final javax.cache cache-api 1.0.0 javax.jms jms-api 1.1-rev-1 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 306 Group ID Artifact ID Version javax.mail javax.mail-api 1.5.5 javax.servlet javax.servlet-api 3.1.0 javax.servlet jstl 1.2 javax.transaction javax.transaction-api 1.2 jaxen jaxen 1.1.6 joda-time joda-time 2.9.4 junit junit 4.12 mysql mysql-connector-java 5.1.39 net.java.dev.jna jna 4.2.2 net.sf.ehcache ehcache 2.10.2 net.sourceforge.htmlunit htmlunit 2.21 net.sourceforge.jtds jtds 1.3.1 net.sourceforge.nekohtml nekohtml 1.9.22 nz.net.ultraq.thymeleaf thymeleaf-layout- dialect 1.4.0 org.apache.activemq activemq-amqp 5.13.3 org.apache.activemq activemq-blueprint 5.13.3 org.apache.activemq activemq-broker 5.13.3 org.apache.activemq activemq-camel 5.13.3 org.apache.activemq activemq-client 5.13.3 org.apache.activemq activemq-console 5.13.3 org.apache.activemq activemq-http 5.13.3 org.apache.activemq activemq-jaas 5.13.3 org.apache.activemq activemq-jdbc-store 5.13.3 org.apache.activemq activemq-jms-pool 5.13.3 org.apache.activemq activemq-kahadb-store 5.13.3 org.apache.activemq activemq-karaf 5.13.3 org.apache.activemq activemq-leveldb-store 5.13.3 org.apache.activemq activemq-log4j-appender 5.13.3 org.apache.activemq activemq-mqtt 5.13.3 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 307 Group ID Artifact ID Version org.apache.activemq activemq-openwire- generator 5.13.3 org.apache.activemq activemq-openwire- legacy 5.13.3 org.apache.activemq activemq-osgi 5.13.3 org.apache.activemq activemq-partition 5.13.3 org.apache.activemq activemq-pool 5.13.3 org.apache.activemq activemq-ra 5.13.3 org.apache.activemq activemq-run 5.13.3 org.apache.activemq activemq-runtime-config 5.13.3 org.apache.activemq activemq-shiro 5.13.3 org.apache.activemq activemq-spring 5.13.3 org.apache.activemq activemq-stomp 5.13.3 org.apache.activemq activemq-web 5.13.3 org.apache.activemq artemis-amqp-protocol 1.2.0 org.apache.activemq artemis-commons 1.2.0 org.apache.activemq artemis-core-client 1.2.0 org.apache.activemq artemis-jms-client 1.2.0 org.apache.activemq artemis-jms-server 1.2.0 org.apache.activemq artemis-journal 1.2.0 org.apache.activemq artemis-native 1.2.0 org.apache.activemq artemis-selector 1.2.0 org.apache.activemq artemis-server 1.2.0 org.apache.activemq artemis-service- extensions 1.2.0 org.apache.commons commons-dbcp2 2.1.1 org.apache.commons commons-pool2 2.4.2 org.apache.derby derby 10.12.1.1 org.apache.httpcomponentshttpasyncclient 4.1.1 org.apache.httpcomponentshttpclient 4.5.2 org.apache.httpcomponentshttpcore 4.4.4 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 308 Group ID Artifact ID Version org.apache.httpcomponentshttpmime 4.5.2 org.apache.logging.log4j log4j-api 2.6 org.apache.logging.log4j log4j-core 2.6 org.apache.logging.log4j log4j-slf4j-impl 2.6 org.apache.solr solr-solrj 5.5.1 org.apache.tomcat tomcat-jdbc 8.0.33 org.apache.tomcat tomcat-jsp-api 8.0.33 org.apache.tomcat.embed tomcat-embed-core 8.0.33 org.apache.tomcat.embed tomcat-embed-el 8.0.33 org.apache.tomcat.embed tomcat-embed-jasper 8.0.33 org.apache.tomcat.embed tomcat-embed-logging- juli 8.0.33 org.apache.tomcat.embed tomcat-embed-websocket 8.0.33 org.apache.velocity velocity 1.7 org.apache.velocity velocity-tools 2.0 org.aspectj aspectjrt 1.8.9 org.aspectj aspectjtools 1.8.9 org.aspectj aspectjweaver 1.8.9 org.assertj assertj-core 2.4.1 org.codehaus.btm btm 2.1.4 org.codehaus.groovy groovy 2.4.6 org.codehaus.groovy groovy-all 2.4.6 org.codehaus.groovy groovy-ant 2.4.6 org.codehaus.groovy groovy-bsf 2.4.6 org.codehaus.groovy groovy-console 2.4.6 org.codehaus.groovy groovy-docgenerator 2.4.6 org.codehaus.groovy groovy-groovydoc 2.4.6 org.codehaus.groovy groovy-groovysh 2.4.6 org.codehaus.groovy groovy-jmx 2.4.6 org.codehaus.groovy groovy-json 2.4.6 org.codehaus.groovy groovy-jsr223 2.4.6 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 309 Group ID Artifact ID Version org.codehaus.groovy groovy-nio 2.4.6 org.codehaus.groovy groovy-servlet 2.4.6 org.codehaus.groovy groovy-sql 2.4.6 org.codehaus.groovy groovy-swing 2.4.6 org.codehaus.groovy groovy-templates 2.4.6 org.codehaus.groovy groovy-test 2.4.6 org.codehaus.groovy groovy-testng 2.4.6 org.codehaus.groovy groovy-xml 2.4.6 org.codehaus.janino janino 2.7.8 org.crashub crash.cli 1.3.2 org.crashub crash.connectors.ssh 1.3.2 org.crashub crash.connectors.telnet 1.3.2 org.crashub crash.embed.spring 1.3.2 org.crashub crash.plugins.cron 1.3.2 org.crashub crash.plugins.mail 1.3.2 org.crashub crash.shell 1.3.2 org.eclipse.jetty jetty-annotations 9.2.17.v20160517 org.eclipse.jetty jetty-client 9.2.17.v20160517 org.eclipse.jetty jetty-continuation 9.2.17.v20160517 org.eclipse.jetty jetty-deploy 9.2.17.v20160517 org.eclipse.jetty jetty-http 9.2.17.v20160517 org.eclipse.jetty jetty-io 9.2.17.v20160517 org.eclipse.jetty jetty-jmx 9.2.17.v20160517 org.eclipse.jetty jetty-jsp 9.2.17.v20160517 org.eclipse.jetty jetty-plus 9.2.17.v20160517 org.eclipse.jetty jetty-security 9.2.17.v20160517 org.eclipse.jetty jetty-server 9.2.17.v20160517 org.eclipse.jetty jetty-servlet 9.2.17.v20160517 org.eclipse.jetty jetty-servlets 9.2.17.v20160517 org.eclipse.jetty jetty-util 9.2.17.v20160517 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 310 Group ID Artifact ID Version org.eclipse.jetty jetty-webapp 9.2.17.v20160517 org.eclipse.jetty jetty-xml 9.2.17.v20160517 org.eclipse.jetty.orbit javax.servlet.jsp 2.2.0.v201112011158 org.eclipse.jetty.websocketjavax-websocket-server- impl 9.2.17.v20160517 org.eclipse.jetty.websocketwebsocket-client 9.2.17.v20160517 org.eclipse.jetty.websocketwebsocket-server 9.2.17.v20160517 org.ehcache ehcache 3.0.1 org.elasticsearch elasticsearch 2.2.2 org.firebirdsql.jdbc jaybird-jdk16 2.2.10 org.firebirdsql.jdbc jaybird-jdk17 2.2.10 org.firebirdsql.jdbc jaybird-jdk18 2.2.10 org.flywaydb flyway-core 3.2.1 org.freemarker freemarker 2.3.23 org.glassfish javax.el 3.0.0 org.glassfish.jersey.containersjersey-container- servlet 2.23 org.glassfish.jersey.containersjersey-container- servlet-core 2.23 org.glassfish.jersey.corejersey-server 2.23 org.glassfish.jersey.ext jersey-bean-validation 2.23 org.glassfish.jersey.ext jersey-spring3 2.23 org.glassfish.jersey.mediajersey-media-json- jackson 2.23 org.hamcrest hamcrest-core 1.3 org.hamcrest hamcrest-library 1.3 org.hibernate hibernate-core 5.1.0.Final org.hibernate hibernate-ehcache 5.1.0.Final org.hibernate hibernate-entitymanager 5.1.0.Final org.hibernate hibernate-envers 5.1.0.Final org.hibernate hibernate-java8 5.1.0.Final org.hibernate hibernate-jpamodelgen 5.1.0.Final Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 311 Group ID Artifact ID Version org.hibernate hibernate-validator 5.2.4.Final org.hibernate hibernate-validator- annotation-processor 5.2.4.Final org.hornetq hornetq-jms-client 2.4.7.Final org.hornetq hornetq-jms-server 2.4.7.Final org.hsqldb hsqldb 2.3.4 org.infinispan infinispan-jcache 8.2.2.Final org.infinispan infinispan-spring4- common 8.2.2.Final org.infinispan infinispan-spring4- embedded 8.2.2.Final org.javassist javassist 3.20.0-GA org.jboss jboss-transaction-spi 7.3.1.Final org.jboss.logging jboss-logging 3.3.0.Final org.jboss.narayana.jta jdbc 5.3.2.Final org.jboss.narayana.jta jms 5.3.2.Final org.jboss.narayana.jta jta 5.3.2.Final org.jboss.narayana.jts narayana-jts- integration 5.3.2.Final org.jdom jdom2 2.0.6 org.jolokia jolokia-core 1.3.3 org.jooq jooq 3.8.2 org.jooq jooq-codegen 3.8.2 org.jooq jooq-meta 3.8.2 org.json json 20140107 org.liquibase liquibase-core 3.5.1 org.mariadb.jdbc mariadb-java-client 1.4.5 org.mockito mockito-core 1.10.19 org.mongodb mongodb-driver 3.2.2 org.mongodb mongo-java-driver 3.2.2 org.neo4j neo4j-ogm-api 2.0.2 org.neo4j neo4j-ogm-compiler 2.0.2 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 312 Group ID Artifact ID Version org.neo4j neo4j-ogm-core 2.0.2 org.neo4j neo4j-ogm-http-driver 2.0.2 org.postgresql postgresql 9.4.1208.jre7 org.projectlombok lombok 1.16.8 org.seleniumhq.selenium htmlunit-driver 2.21 org.seleniumhq.selenium selenium-api 2.53.0 org.seleniumhq.selenium selenium-java 2.53.0 org.seleniumhq.selenium selenium-remote-driver 2.53.0 org.seleniumhq.selenium selenium-support 2.53.0 org.skyscreamer jsonassert 1.3.0 org.slf4j jcl-over-slf4j 1.7.21 org.slf4j jul-to-slf4j 1.7.21 org.slf4j log4j-over-slf4j 1.7.21 org.slf4j slf4j-api 1.7.21 org.slf4j slf4j-jdk14 1.7.21 org.slf4j slf4j-log4j12 1.7.21 org.slf4j slf4j-simple 1.7.21 org.spockframework spock-core 1.0-groovy-2.4 org.spockframework spock-spring 1.0-groovy-2.4 org.springframework spring-aop 4.3.0.RELEASE org.springframework spring-aspects 4.3.0.RELEASE org.springframework spring-beans 4.3.0.RELEASE org.springframework spring-context 4.3.0.RELEASE org.springframework spring-context-support 4.3.0.RELEASE org.springframework spring-core 4.3.0.RELEASE org.springframework spring-expression 4.3.0.RELEASE org.springframework spring-instrument 4.3.0.RELEASE org.springframework spring-instrument- tomcat 4.3.0.RELEASE org.springframework spring-jdbc 4.3.0.RELEASE org.springframework spring-jms 4.3.0.RELEASE Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 313 Group ID Artifact ID Version org.springframework springloaded 1.2.6.RELEASE org.springframework spring-messaging 4.3.0.RELEASE org.springframework spring-orm 4.3.0.RELEASE org.springframework spring-oxm 4.3.0.RELEASE org.springframework spring-test 4.3.0.RELEASE org.springframework spring-tx 4.3.0.RELEASE org.springframework spring-web 4.3.0.RELEASE org.springframework spring-webmvc 4.3.0.RELEASE org.springframework spring-webmvc-portlet 4.3.0.RELEASE org.springframework spring-websocket 4.3.0.RELEASE org.springframework.amqp spring-amqp 1.6.0.RELEASE org.springframework.amqp spring-rabbit 1.6.0.RELEASE org.springframework.batchspring-batch-core 3.0.7.RELEASE org.springframework.batchspring-batch- infrastructure 3.0.7.RELEASE org.springframework.batchspring-batch- integration 3.0.7.RELEASE org.springframework.batchspring-batch-test 3.0.7.RELEASE org.springframework.boot spring-boot 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-actuator 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-actuator- docs 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot- autoconfigure 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot- configuration-metadata 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot- configuration-processor 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-devtools 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-loader 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-loader- tools 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter 1.4.0.BUILD-SNAPSHOT Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 314 Group ID Artifact ID Version org.springframework.boot spring-boot-starter- activemq 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- actuator 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- amqp 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter-aop 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- artemis 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- batch 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- cache 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- cloud-connectors 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-cassandra 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-couchbase 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-elasticsearch 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-gemfire 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-jpa 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-mongodb 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-neo4j 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-redis 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-rest 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- data-solr 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- freemarker 1.4.0.BUILD-SNAPSHOT Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 315 Group ID Artifact ID Version org.springframework.boot spring-boot-starter- groovy-templates 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- hateoas 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- hornetq 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- integration 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jdbc 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jersey 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jetty 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jooq 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jta-atomikos 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jta-bitronix 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- jta-narayana 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- log4j2 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- logging 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- mail 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- mobile 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- mustache 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- redis 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- remote-shell 1.4.0.BUILD-SNAPSHOT Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 316 Group ID Artifact ID Version org.springframework.boot spring-boot-starter- security 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- social-facebook 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- social-linkedin 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- social-twitter 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- test 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- thymeleaf 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- tomcat 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- undertow 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- validation 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- velocity 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter-web 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- web-services 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter- websocket 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-starter-ws 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-test 1.4.0.BUILD-SNAPSHOT org.springframework.boot spring-boot-test- autoconfigure 1.4.0.BUILD-SNAPSHOT org.springframework.cloudspring-cloud- cloudfoundry-connector 1.2.2.RELEASE org.springframework.cloudspring-cloud-core 1.2.2.RELEASE org.springframework.cloudspring-cloud-heroku- connector 1.2.2.RELEASE org.springframework.cloudspring-cloud- localconfig-connector 1.2.2.RELEASE Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 317 Group ID Artifact ID Version org.springframework.cloudspring-cloud-spring- service-connector 1.2.2.RELEASE org.springframework.data spring-cql 1.4.2.BUILD-SNAPSHOT org.springframework.data spring-data-cassandra 1.4.2.BUILD-SNAPSHOT org.springframework.data spring-data-commons 1.12.2.BUILD-SNAPSHOT org.springframework.data spring-data-couchbase 2.1.2.BUILD-SNAPSHOT org.springframework.data spring-data- elasticsearch 2.0.2.BUILD-SNAPSHOT org.springframework.data spring-data-envers 1.0.2.BUILD-SNAPSHOT org.springframework.data spring-data-gemfire 1.8.2.BUILD-SNAPSHOT org.springframework.data spring-data-jpa 1.10.2.BUILD-SNAPSHOT org.springframework.data spring-data-keyvalue 1.1.2.BUILD-SNAPSHOT org.springframework.data spring-data-mongodb 1.9.2.BUILD-SNAPSHOT org.springframework.data spring-data-mongodb- cross-store 1.9.2.BUILD-SNAPSHOT org.springframework.data spring-data-mongodb- log4j 1.9.2.BUILD-SNAPSHOT org.springframework.data spring-data-neo4j 4.1.2.BUILD-SNAPSHOT org.springframework.data spring-data-redis 1.7.2.BUILD-SNAPSHOT org.springframework.data spring-data-rest-core 2.5.2.BUILD-SNAPSHOT org.springframework.data spring-data-rest-hal- browser 2.5.2.BUILD-SNAPSHOT org.springframework.data spring-data-rest-webmvc 2.5.2.BUILD-SNAPSHOT org.springframework.data spring-data-solr 2.0.2.BUILD-SNAPSHOT org.springframework.hateoasspring-hateoas 0.20.0.RELEASE org.springframework.integrationspring-integration-amqp 4.3.0.RC1 org.springframework.integrationspring-integration-core 4.3.0.RC1 org.springframework.integrationspring-integration- event 4.3.0.RC1 org.springframework.integrationspring-integration-feed 4.3.0.RC1 org.springframework.integrationspring-integration-file 4.3.0.RC1 org.springframework.integrationspring-integration-ftp 4.3.0.RC1 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 318 Group ID Artifact ID Version org.springframework.integrationspring-integration- gemfire 4.3.0.RC1 org.springframework.integrationspring-integration- groovy 4.3.0.RC1 org.springframework.integrationspring-integration-http 4.3.0.RC1 org.springframework.integrationspring-integration-ip 4.3.0.RC1 org.springframework.integrationspring-integration- java-dsl 1.1.2.RELEASE org.springframework.integrationspring-integration-jdbc 4.3.0.RC1 org.springframework.integrationspring-integration-jms 4.3.0.RC1 org.springframework.integrationspring-integration-jmx 4.3.0.RC1 org.springframework.integrationspring-integration-jpa 4.3.0.RC1 org.springframework.integrationspring-integration-mail 4.3.0.RC1 org.springframework.integrationspring-integration- mongodb 4.3.0.RC1 org.springframework.integrationspring-integration-mqtt 4.3.0.RC1 org.springframework.integrationspring-integration- redis 4.3.0.RC1 org.springframework.integrationspring-integration-rmi 4.3.0.RC1 org.springframework.integrationspring-integration- scripting 4.3.0.RC1 org.springframework.integrationspring-integration- security 4.3.0.RC1 org.springframework.integrationspring-integration-sftp 4.3.0.RC1 org.springframework.integrationspring-integration- stomp 4.3.0.RC1 org.springframework.integrationspring-integration- stream 4.3.0.RC1 org.springframework.integrationspring-integration- syslog 4.3.0.RC1 org.springframework.integrationspring-integration-test 4.3.0.RC1 org.springframework.integrationspring-integration- twitter 4.3.0.RC1 org.springframework.integrationspring-integration- websocket 4.3.0.RC1 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 319 Group ID Artifact ID Version org.springframework.integrationspring-integration-ws 4.3.0.RC1 org.springframework.integrationspring-integration-xml 4.3.0.RC1 org.springframework.integrationspring-integration-xmpp 4.3.0.RC1 org.springframework.integrationspring-integration- zookeeper 4.3.0.RC1 org.springframework.mobilespring-mobile-device 1.1.5.RELEASE org.springframework.pluginspring-plugin-core 1.2.0.RELEASE org.springframework.restdocsspring-restdocs-core 1.1.0.RELEASE org.springframework.restdocsspring-restdocs-mockmvc 1.1.0.RELEASE org.springframework.restdocsspring-restdocs- restassured 1.1.0.RELEASE org.springframework.retryspring-retry 1.1.2.RELEASE org.springframework.securityspring-security-acl 4.1.0.RELEASE org.springframework.securityspring-security-aspects 4.1.0.RELEASE org.springframework.securityspring-security-cas 4.1.0.RELEASE org.springframework.securityspring-security-config 4.1.0.RELEASE org.springframework.securityspring-security-core 4.1.0.RELEASE org.springframework.securityspring-security-crypto 4.1.0.RELEASE org.springframework.securityspring-security-data 4.1.0.RELEASE org.springframework.securityspring-security-jwt 1.0.4.RELEASE org.springframework.securityspring-security-ldap 4.1.0.RELEASE org.springframework.securityspring-security- messaging 4.1.0.RELEASE org.springframework.securityspring-security-openid 4.1.0.RELEASE org.springframework.securityspring-security- remoting 4.1.0.RELEASE org.springframework.securityspring-security-taglibs 4.1.0.RELEASE org.springframework.securityspring-security-test 4.1.0.RELEASE org.springframework.securityspring-security-web 4.1.0.RELEASE org.springframework.security.oauthspring-security-oauth 2.0.10.RELEASE org.springframework.security.oauthspring-security-oauth2 2.0.10.RELEASE org.springframework.sessionspring-session 1.2.0.RELEASE Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 320 Group ID Artifact ID Version org.springframework.sessionspring-session-data- gemfire 1.2.0.RELEASE org.springframework.sessionspring-session-data- mongo 1.2.0.RELEASE org.springframework.sessionspring-session-data- redis 1.2.0.RELEASE org.springframework.sessionspring-session-jdbc 1.2.0.RELEASE org.springframework.socialspring-social-config 1.1.4.RELEASE org.springframework.socialspring-social-core 1.1.4.RELEASE org.springframework.socialspring-social-facebook 2.0.3.RELEASE org.springframework.socialspring-social-facebook- web 2.0.3.RELEASE org.springframework.socialspring-social-linkedin 1.0.2.RELEASE org.springframework.socialspring-social-security 1.1.4.RELEASE org.springframework.socialspring-social-twitter 1.1.2.RELEASE org.springframework.socialspring-social-web 1.1.4.RELEASE org.springframework.ws spring-ws-core 2.3.0.RELEASE org.springframework.ws spring-ws-security 2.3.0.RELEASE org.springframework.ws spring-ws-support 2.3.0.RELEASE org.springframework.ws spring-ws-test 2.3.0.RELEASE org.thymeleaf thymeleaf 2.1.4.RELEASE org.thymeleaf thymeleaf-spring4 2.1.4.RELEASE org.thymeleaf.extras thymeleaf-extras- conditionalcomments 2.1.1.RELEASE org.thymeleaf.extras thymeleaf-extras- java8time 2.1.0.RELEASE org.thymeleaf.extras thymeleaf-extras- springsecurity4 2.1.2.RELEASE org.webjars hal-browser 9f96c74 org.webjars webjars-locator 0.31 org.xerial sqlite-jdbc 3.8.11.2 org.yaml snakeyaml 1.17 redis.clients jedis 2.8.1 Spring Boot Reference Guide 1.4.0.BUILD-SNAPSHOT Spring Boot 321 Group ID Artifact ID Version wsdl4j wsdl4j 1.6.3 xml-apis xml-apis 1.4.01
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