Hibernate Component映射的一个简单例子

jopen 8年前

Hibernate Component映射的一个简单例子

建立一个相关的数据库表:

create table c_user(  id int(11) not null auto_increment,  age int(11) default null,  firstname varchar(50) default null,  lastname varchar(50) default null,  address varchar(200) default null,  zipcode varchar(10) default null,  tel varchar(20) default null,  primary key(id)  )engine=innodb default charset=gbk;

注解:该表是一个用户信息表,可以将用户信息归纳为两个部分:一个部分是name(姓名),包含firstname()lastname();另一部分是contact(联系方式),包括了address(地址)zipcode(邮编)tel(电话)等信息。在创建实体类时,可以将namecontact分别封装到2个独立的类中,这样就提高了系统的复用性和灵活性。也就是说,需要使用Component映射,将其他的实体类映射在一起。

建立一个Name.java类:

package collect.component;    import java.io.Serializable;    public class Name implements Serializable {            private String firstname;      private String lastname;            public String getFirstname() {          return firstname;      }      public void setFirstname(String firstname) {          this.firstname = firstname;      }      public String getLastname() {          return lastname;      }      public void setLastname(String lastname) {          this.lastname = lastname;      }        }

建立联系方式相关的类Contact.java:

package collect.component;    import java.io.Serializable;    public class Contact implements Serializable{     private String address;   private String zipcodes;   private String tel;     public Contact() {}      public String getAddress() {    return address;   }     public void setAddress(String address) {    this.address = address;   }     public String getZipcodes() {    return zipcodes;   }     public void setZipcodes(String zipcodes) {    this.zipcodes = zipcodes;   }     public String getTel() {    return tel;   }     public void setTel(String tel) {    this.tel = tel;   }    }

最后建立数据库表对应的实体类Cuser.java

package collect.component;    public class Cuser {   private Integer id;   private Integer age;   private Name name;   private Contact contact;     public Integer getId() {    return id;   }     public void setId(Integer id) {    this.id = id;   }     public Integer getAge() {    return age;   }     public void setAge(Integer age) {    this.age = age;   }     public Name getName() {    return name;   }     public void setName(Name name) {    this.name = name;   }     public Contact getContact() {    return contact;   }     public void setContact(Contact contact) {    this.contact = contact;   }    }

建立映射文件Cuser.hbm.xml:

<?xml version="1.0"?>  <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">  <hibernate-mapping>      <class name="collect.component.Cuser" table="c_user" catalog="ssh">          <id name="id" type="integer">              <column name="id" />              <generator class="native" />          </id>          <property name="age" type="integer">              <column name="age" />          </property>          <component name="name" class="collect.component.Name">              <property name="firstname" type="string">                  <column name="firstname" length="50" />              </property>              <property name="lastname" type="string">                  <column name="lastname" length="50" />              </property>          </component>          <component name="contact" class="collect.component.Contact">              <property name="address" type="string">                  <column name="address" length="200" />              </property>              <property name="zipcodes" type="string">                  <column name="zipcode" length="10" />              </property>              <property name="tel" type="string">                  <column name="tel" length="20" />              </property>          </component>      </class>  </hibernate-mapping>

注解:映射文件使用component元素将Name类、Contact类同数据库表c_user联系起来。

将该映射文件加入到Hibernate的配置文件中,建立一个测试类Test.java:

package collect.component;    import org.hibernate.Session;  import org.hibernate.SessionFactory;  import org.hibernate.Transaction;  import org.hibernate.cfg.Configuration;    public class Test {     public static void main(String[] args) {    // Configuration管理Hibernate配置    Configuration config = new Configuration().configure();    // 根据Configuration建立 SessionFactory    // SessionFactory用来建立Session    SessionFactory sessionFactory = config.buildSessionFactory();      // 创建实例    Name name=new Name();    name.setFirstname("闫");    name.setLastname("术卓");        Contact contact = new Contact();          contact.setAddress("北京");          contact.setTel("42689334");          contact.setZipcodes("100085");              Cuser user= new Cuser();    user.setAge(33);    user.setName(name);    user.setContact(contact);        // 定义主键变量    Integer pid;      // 添加数据    Session session = sessionFactory.openSession();    Transaction tx = null;    try {     tx = session.beginTransaction();     // 创建主键变量     pid = (Integer) session.save(user);     tx.commit();    } catch (RuntimeException e) {     if (tx != null)      tx.rollback();     throw e;    } finally {     session.close();    }      // 关闭sessionFactory    sessionFactory.close();     }    }

 

运行结果:

控制台:

20:47:57,366 DEBUG SQL:346 - insert intossh.c_user (age, firstname, lastname, address, zipcode, tel) values (?, ?, ?,?, ?, ?)

数据库:

Hibernate Component映射的一个简单例子