NoSQL 之 Morphia 操作 MongoDB
上两篇文章:http://www.cnblogs.com/hoojo/archive/2011/06/01/2066426.html
http://www.cnblogs.com/hoojo/archive/2011/06/02/2068665.html
介绍到了在MongoDB的控制台完成MongoDB的数据操作、以及通过Java MongoDB 的驱动完成在Java中对MongoDB的操作,通过前两篇文章我们对MongoDB有了全面、深刻的认识和理解。现在我们就看看利用Morphia库来操作MongoDB。
开发环境:
System:Windows
IDE:eclipse、MyEclipse 8
Database:mongoDB
开发依赖库:
JavaEE5、mongo-2.5.3.jar、junit-4.8.2.jar, morphia-0.99.jar
Email:hoojo_@126.com
Blog:http://blog.csdn.net/IBM_hoojo
一、准备工作
1、 首先,下载mongoDB对Java支持的驱动包
驱动包下载地址:https://github.com/mongodb/mongo-java-driver/downloads
mongoDB对Java的相关支持、技术:http://www.mongodb.org/display/DOCS/Java+Language+Center
驱动源码下载:https://download.github.com/mongodb-mongo-java-driver-r2.6.1-7-g6037357.zip
在线查看源码:https://github.com/mongodb/mongo-java-driver
Morphia jar包下载:http://code.google.com/p/morphia/downloads/list
2、 下面建立一个JavaProject工程,导入下载下来的驱动包。即可在Java中使用Morphia,目录如下:
二、Java操作MongoDB示例
在本示例之前你需要启动mongod.exe的服务,在你安装mongoDB的目录中,找到mongod.exe启动服务后,下面的程序才能顺利执行;
1、 Java操作mongoDB数据库,操作索引
Mongo mongo = new Mongo();
这样就创建了一个MongoDB的数据库连接对象,它默认连接到当前机器的localhost地址,端口是27017。
DB db = mongo.getDB(“test”);
这样就获得了一个test的数据库,如果mongoDB中没有创建这个数据库也是可以正常运行的。如果你读过上一篇文章就知道,mongoDB可以在没有创建这个数据库的情况下,完成数据的添加操作。当添加的时候,没有这个库,mongoDB会自动创建当前数据库。
得到了db,下一步我们要获取一个“聚集集合DBCollection”,通过db对象的getCollection方法来完成。
DBCollection users = db.getCollection("users");
这样就获得了一个DBCollection,它相当于我们数据库的“表”。
查询所有数据
DBCursor cur = users.find();
while (cur.hasNext()) {
System.out.println(cur.next());
}
用BasicDBObjectBuilder,向users对象中添加数据
user = BasicDBObjectBuilder.start("id", 1546555)
.append("name", "jojo").add("address", "gz")
.append("email", "hoojo_@126.com")
.get();
插入数据
users.insert(user);
可以利用JSON工具来序列化对象数据
JSON.serialize(cur)
完整源码
package com.hoo.test;import java.net.UnknownHostException;import com.hoo.entity.User;import com.hoo.util.BasicDBObjectUtils;import com.mongodb.BasicDBObjectBuilder;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.DBObject;import com.mongodb.Mongo;import com.mongodb.MongoException;import com.mongodb.util.JSON;/** * <b>function:</b> Mongo实例对象的相关方法测试 * @author hoojo * @createDate 2011-5-24 下午02:42:29 * @file MongoDBTest.java * @package com.hoo.test * @project MongoDB * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */public class MongoDBTest {
public static void main(String[] args) throws UnknownHostException, MongoException {
        Mongo mg = new Mongo();        System.out.println("查询所有的Database的名称");        for (String name : mg.getDatabaseNames()) {            System.out.println("dbName: " + name);}
        System.out.println("查询test库中的所有collection集合(表)名称");        DB db = mg.getDB("test");        for (String name : db.getCollectionNames()) {            System.out.println("collectionName: " + name);}
        System.out.println("添加测试数据");        DBCollection users = db.getCollection("users");        try {            // 用自定义BasicDBObjectUtils工具类,将User Enity对象转换成DBObjectDBObject user = BasicDBObjectUtils.castModel2DBObject(new User("345567", "jack", 22, "beijin"));
users.insert(user);
            // 用BasicDBObjectBuilder构建一个DBObject对象user = BasicDBObjectBuilder.start("id", 1546555).append("name", "jojo").add("address", "gz").append("email", "hoojo_@126.com").get();
users.insert(user);
        } catch (Exception e) {e.printStackTrace();
}
        System.out.println("游标查询所有users集合数据");DBCursor cur = users.find();
        while (cur.hasNext()) {System.out.println(cur.next());
}
        System.out.println("查询游标相关内容");System.out.println(cur.count());
System.out.println(cur.getCursorId());
System.out.println(cur.getOptions());
System.out.println(cur.getQuery());
System.out.println(cur.getSizes().listIterator());
System.out.println(cur.itcount());
        //System.out.println(cur.length());System.out.println(cur.size());
System.out.println(cur.numGetMores());
System.out.println(cur.curr());
        //System.out.println(cur.toArray().get(0));        System.out.println("显示游标查询到的所有内容: " + JSON.serialize(cur));}
}
工具类,将带有getter、setter方法的Java类序列化成DBObject对象
package com.hoo.util;import java.lang.reflect.Method;import com.mongodb.BasicDBObject;import com.mongodb.DBObject;/** * <b>function:</b> 将Entity/Model转换成DBObject * @author hoojo * @createDate 2011-5-30下午01:53:08 * @file BasicDBObjectUtil.java * @package com.hoo.util * @project MongoDB * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */publicclass BasicDBObjectUtils {public static<T> DBObject castModel2DBObject(T entity) throws Exception {
Method[] method = entity.getClass().getMethods();
        DBObject dbObject = new BasicDBObject();        for (Method m : method) {            //System.out.println(m.getName());if (m.getName().startsWith("get")) {
String name = m.getName().replace("get", "");
                for (Method m2 : method) {if (m2.getName().equals("set" + name)) {
name = name.substring(0, 1).toLowerCase() + name.substring(1);
                        Object returnVal = m.invoke(entity, new Object[] {});                        if (returnVal != null) {                            //System.out.println(name + " : " + m.invoke(shipping, new Object[] {}));dbObject.put(name, returnVal);
}
}
}
}
}
        System.out.println("dbObject: " + dbObject);        return dbObject;}
}
2、 完成索引操作,首先建立一个MongoDB4IndexTest.java,基本测试代码如下:
package com.hoo.test;import java.net.UnknownHostException;import java.util.ArrayList;import java.util.List;import org.bson.types.ObjectId;import org.junit.After;import org.junit.Before;import org.junit.Test;import com.mongodb.BasicDBObject;import com.mongodb.Bytes;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.DBObject;import com.mongodb.Mongo;import com.mongodb.MongoException;import com.mongodb.QueryOperators;import com.mongodb.util.JSON;/** * <b>function:</b> 实现MongoDB的Index操作 * @author hoojo * @createDate 2011-6-2 下午03:21:23 * @file MongoDB4IndexTest.java * @package com.hoo.test * @project MongoDB * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */public class MongoDB4IndexTest {
    private Mongo mg = null;    private DB db;    private DBCollection users;@Before
public void init() {
        try {            mg = new Mongo();            //mg = new Mongo("localhost", 27017);        } catch (UnknownHostException e) {e.printStackTrace();
        } catch (MongoException e) {e.printStackTrace();
}
        //获取temp DB;如果默认没有创建,mongodb会自动创建        db = mg.getDB("temp");        //获取users DBCollection;如果默认没有创建,mongodb会自动创建        users = db.getCollection("users");}
@After
public void destory() {
        if (mg != null)mg.close();
mg = null;
db = null;
users = null;
System.gc();
}
public void print(Object o) {
System.out.println(o);
}
}
3、 下面完成对象Collection的index的操作
/** * <b>function:</b> 测试Collection的index相关操作 * @author hoojo * @createDate 2012-2-16 下午08:32:26 */@Test
public void testIndex() {
query();
    for (DBObject index : coll.getIndexInfo()) {        print("IndexInfo: " + index);}
coll.dropIndexes();
    //创建索引coll.createIndex(new BasicDBObject("name", "idx_name"));
print(coll.findOne(new BasicDBObject("name", "haha")));
coll.createIndex(coll.findOne(new BasicDBObject("name", "haha")));
DBObject o = new BasicDBObject("unique", true);
    //coll.createIndex(coll.findOne(), o);    // 修改索引,如果存在就修改不存在就添加coll.ensureIndex(o);
    coll.ensureIndex("age_1");coll.ensureIndex(new BasicDBObject("age3_1", 6), new BasicDBObject("ts", -1));
coll.ensureIndex(new BasicDBObject("age_2", 1), new BasicDBObject( "ts" , 1 ));
coll.ensureIndex(new BasicDBObject("password", 2), new BasicDBObject( "z" , "idx" ));
coll.ensureIndex(new BasicDBObject("password", 1), new BasicDBObject( "etc" , "idx" ));
    // 创建唯一索引coll.ensureIndex(new BasicDBObject("emial", 2), new BasicDBObject("unique", false));
    // 创建索引,指定索引名称default_indexcoll.ensureIndex(new BasicDBObject("address", 1), new BasicDBObject( "name" , "default_index"));
    // 创建索引对象,索引名称user_indexcoll.ensureIndex(coll.findOne(new BasicDBObject("name", "hoho")), "user_index");
    // 唯一索引coll.ensureIndex(coll.findOne(new BasicDBObject("name", "hehe")), "users_index_unique", true);
    // 查询所有索引    for (DBObject index : coll.getIndexInfo()) {        print("IndexInfo: " + index);}
print(DBCollection.genIndexName(coll.findOne()));
    //coll.dropIndex(coll.findOne());print(DBCollection.genIndexName(new BasicDBObject("password", 2)));
    //coll.dropIndex(DBCollection.genIndexName(new BasicDBObject("password", 2)));    //coll.dropIndexes();    //coll.dropIndexes("assword_1");}
三、Morphia基本操作
1、 morphia可以利用annotation对JavaEntity进行注解,那样我们就可以用morphia操作JavaEntity对象
package com.hoo.entity;import com.google.code.morphia.annotations.Entity;import com.google.code.morphia.annotations.Id;/** * <b>function:</b> JavaEntity对象 * @author hoojo * @createDate 2011-5-31上午11:45:21 * @file User.java * @package com.hoo.entity * @project Morphia * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 *///利用morphia的annotation进行注解@Entity
public class User {
@Id
private long id;
    private String name;private boolean sex;
private int age;
    private String address;    public User() {}
public User(long id, String name, boolean sex, int age, String address) {
        super();        this.id = id;        this.name = name;        this.sex = sex;        this.age = age;        this.address = address;}
    //getter、setter@Override
    public String toString() {return this.id + "#" + this.name + "#" + this.age + "#" + this.sex + "#" + this.address;
}
}
2、 对Morphia对象一些简单的使用,看看该对象提供了哪些基本的操作方法
package com.hoo.test.morphia;import java.net.UnknownHostException;import org.junit.After;import org.junit.Before;import org.junit.Test;import com.google.code.morphia.Datastore;import com.google.code.morphia.EntityInterceptor;import com.google.code.morphia.Morphia;import com.google.code.morphia.mapping.MappedClass;import com.google.code.morphia.mapping.Mapper;import com.google.code.morphia.mapping.cache.EntityCache;import com.hoo.entity.User;import com.mongodb.BasicDBObjectBuilder;import com.mongodb.Mongo;import com.mongodb.MongoException;/** * <b>function:</b> morphia对象的简单测试 * @author hoojo * @createDate 2011-5-31上午11:30:20 * @file MorphiaTest.java * @package com.hoo.test * @project Morphia * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */public class MorphiaTest {
    private Mongo mongo;    private Morphia morphia;@Before
public void init() {
        try {            mongo = new Mongo();        } catch (UnknownHostException e) {e.printStackTrace();
        } catch (MongoException e) {e.printStackTrace();
}
        morphia = new Morphia();}
private void print(Object o) {
        if (o != null) {System.out.println(o.toString());
}
}
    /**     * <b>function:</b> morphia对象的简单测试     * @author hoojo     */    @SuppressWarnings("deprecation")@Test
public void testMorphia() {
        // 创建一个Datastore,过时的方法不推荐使用        Datastore ds = morphia.createDatastore("myTestDB");        print("createDatastore: " + ds);        // 创建ds        ds = morphia.createDatastore(mongo, "myTestDB");        print("createDatastore: " + ds);        // 创建一个带用户名、密码的ds        //ds = morphia.createDatastore(mongo, "myTestDB", "admin", new char[] { '1', '2', '3', '4', '5', '6' });        // 设置操作资源对象,这里设置User.class 就可以完成对User的一系列操作        //morphia.map(User.class);        //morphia.mapPackage("com.hoo.entity");//会把整个包下面的类都加载进来        // 将对象转成DBObjectprint("toDBObject: " + morphia.toDBObject(new User(System.currentTimeMillis(), "jackson", true, 22, null)));
        // 将参数2转换成参数1的类型print("fromDBObject: " + morphia.fromDBObject(User.class, BasicDBObjectBuilder.start("sex", true).get()));
        print("getMapper: " + morphia.getMapper());print("isMapped: " + morphia.isMapped(User.class));
}
    /**     * <b>function:</b> 对Mapper对象相关操作     * @author hoojo     * @createDate 2012-2-16下午10:20:38     */@Test
public void testMapper() {
Mapper mapper = morphia.getMapper();
        // 添加对象映射print("addMappedClass: " + mapper.addMappedClass(User.class));
        //print(mapper.addMappedClass(mapper.addMappedClass(User.class));        // 创建实体缓存        print("createEntityCache: " + mapper.createEntityCache());        print(mapper.getCollectionName("myTestDB"));print(mapper.getConverters());
User user = new User(System.currentTimeMillis(), "jackson", true, 22, null);
user.setId(1306814012734L);
print(mapper.getId(user));
        for (EntityInterceptor ei : mapper.getInterceptors()) {            System.out.println("EntityInterceptor: " + ei);}
        // 查询主键        print("getKey: " + mapper.getKey(user));        // 所有已经映射的class        for (MappedClass mc : mapper.getMappedClasses()) {            System.out.println("getMappedClasses: " + mc);}
        print("mcMap: " + mapper.getMCMap());        print("getOptions: " + mapper.getOptions());        print("keyToRef: " + mapper.keyToRef(mapper.getKey(user)));        print("refToKey: " + mapper.refToKey(mapper.keyToRef(mapper.getKey(user))));}
    /**     * <b>function:</b> 实体缓存     * @author hoojo     */@Test
public void testEntityCache() {
EntityCache ec = morphia.getMapper().createEntityCache();
        print("EntityCache: " + ec);        Datastore ds = morphia.createDatastore(mongo, "myTestDB");User user = new User(System.currentTimeMillis(), "jackson", true, 22, null);
user.setId(1306814012734L);
        // 添加实体ec.putEntity(ds.getKey(user), user);
        // 代理ec.putProxy(ds.getKey(user), user);
        print("getKey: " + ds.getKey(user));        print("getProxy: " + ec.getProxy(ds.getKey(user)));        print("getEntity: " + ec.getEntity(ds.getKey(user)));print(ec.exists(ds.getKey(user)));
        print("stats: " + ec.stats());}
@After
public void destory() {
mongo = null;
morphia = null;
System.gc();
}
}
四、利用Morphia完成对Datastore对象的CRUD操作
1、 首先添加如下准备代码,随后的方法直接添加到该文件中即可
package com.hoo.test.ds;import java.net.UnknownHostException;import java.util.ArrayList;import java.util.List;import org.junit.After;import org.junit.Before;import org.junit.Test;import com.google.code.morphia.Datastore;import com.google.code.morphia.Key;import com.google.code.morphia.Morphia;import com.google.code.morphia.query.UpdateOperations;import com.hoo.entity.User;import com.mongodb.Mongo;import com.mongodb.MongoException;/** * <b>function:</b> Datastore增删改查操作 * @author hoojo * @createDate 2011-5-31下午06:29:04 * @fileDatastore DatastoreTest.java * @package com.hoo.test.ds * @project Morphia * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */public class DatastoreTest {
    private Mongo mongo;    private Morphia morphia;    private Datastore ds;@Before
public void init() {
        try {            mongo = new Mongo();        } catch (UnknownHostException e) {e.printStackTrace();
        } catch (MongoException e) {e.printStackTrace();
}
        morphia = new Morphia();        morphia.map(User.class);        ds = morphia.createDatastore(mongo, "temp");}
private void print(Object o) {
        if (o != null) {System.out.println(o.toString());
}
}
    /**    * <b>function:</b> 查询所有    * @author hoojo    * @createDate 2012-2-16 下午10:36:13    */private void query() {
        Iterable<User> it = ds.createQuery(User.class).fetch();        while(it.iterator().hasNext()) {            print("fetch: " + it.iterator().next());}
}
@After
public void destory() {
mongo = null;
morphia = null;
ds = null;
System.gc();
}
}
2、 增删改CUD操作
/** * <b>function:</b> CUD增删改 * @author hoojo * @createDate 2012-2-16 下午10:46:08 */@Test
public void testCUD() {
    // 添加测试数据for (int i = 0; i < 50; i++) {
User u = new User(System.currentTimeMillis() + i, "test-" + i, ((i % 2 == 0)? true: false), 18 + i, "china-gz#" + i);
print(ds.save(u));
}
    //ds.delete(ds.createQuery(User.class));    List<User> users = new ArrayList<User>();users.add(new User(1306907246518L, "zhangsan", true, 22, "china-gz"));
User user = new User(System.currentTimeMillis() + 3, "zhaoliu", true, 29, "china-beijin");
users.add(user);
users.add(new User(System.currentTimeMillis() + 6, "wangwu", true, 24, "china-shanghai"));
users.add(new User(System.currentTimeMillis() + 9, "lisi", true, 26, "china-wuhan"));
    //添加集合    print("save: " + ds.save(users));    //添加数组    print("save: " + ds.save(users.toArray()));    this.query();print("getKey: " + ds.find(User.class, "id", 1306907246518L).getKey());
    //修改操作    UpdateOperations<User> uo = ds.createUpdateOperations(User.class);print("update: " + ds.update(ds.find(User.class, "id", 1306907246518L).getKey(), uo).getUpdatedCount());
uo.add("name", "zhaoliuliu").set("age", 29).set("sex", true).add("address", "gzz");
print("update: " + ds.update(ds.find(User.class, "id", 1306907246518L).getKey(), uo).getUpdatedCount());
print("update: " + ds.update(ds.createQuery(User.class).field("id").equal(1306907246518L), uo).getUpdatedCount());
print("update: " + ds.update(ds.find(User.class, "id", 1306907246518L), uo).getUpdatedCount());
    uo = ds.createUpdateOperations(User.class);uo.set("name", "zhaoqq").set("age", 29).set("sex", true).add("address", "fzz");
print("update: " + ds.update(ds.find(User.class, "id", 1306907246518L).get(), uo).getUpdatedCount());
print("update: " + ds.update(ds.createQuery(User.class).field("id").equal(1306907246518L), uo, true).getUpdatedCount());
    // 修改第一个对象print("updateFirst: " + ds.updateFirst(ds.createQuery(User.class).field("id").equal(1306907246518L), uo).getUpdatedCount());
    //当参数createIfMissing为true的时候,如果修改的对象不存在就会添加这条数据,如果为false的情况下,不存在也不添加print("updateFirst: " + ds.updateFirst(ds.createQuery(User.class).field("id").equal(1306907246519L), uo, true).getUpdatedCount());
user.setId(1306907246518L);
print("updateFirst: " + ds.updateFirst(ds.createQuery(User.class).field("id").equal(1306907246518L), user, true).getUpdatedCount());
user.setId(1306916670518L);
    // 合并    print("merge: " + ds.merge(user).getId());    this.query();    //删除print("delete: " + ds.delete(ds.createQuery(User.class).field("id").equal(1306907246518L)).getN());
print("delete: " + ds.delete(ds.find(User.class, "age", 29).get()).getN());
    //print("delete: " + ds.delete(User.class, 1306911594631L).getN());    //print("delete: " + ds.delete(User.class, users).getN());    //ds.delete(ds.createQuery(User.class));    this.query();}
3、 Find查询操作
/** * <b>function:</b> find查询 * @author hoojo * @createDate 2012-2-16 下午10:45:55 */@Test
public void testFind() {
print("find: " + ds.find(User.class).asList());
    //likeprint("find-contains: " + ds.find(User.class).field("name").contains("test-1").asList());
    //忽略大小写print("find-containsIgnoreCase: " + ds.find(User.class).field("name").containsIgnoreCase("ja").asList());
print("find-endsWith: " + ds.find(User.class).field("name").endsWith("22").asList());
print("find-endsWithIgnoreCase: " + ds.find(User.class).field("name").endsWithIgnoreCase("CK").asList());
    //过滤null或是没有name属性的print("find-doesNotExist: " + ds.find(User.class).field("name").doesNotExist().asList());
    //查询name有值的数据print("find-doesNotExist: " + ds.find(User.class).field("name").exists().asList());
    //age > 48print("find-greaterThan: " + ds.find(User.class).field("age").greaterThan(66).asList());
    //age >= 48print("find-greaterThan: " + ds.find(User.class).field("age").greaterThanOrEq(66).asList());
    List<Integer> ageList = new ArrayList<Integer>(); ageList.add(22);
ageList.add(55);
ageList.add(66);
    //allprint("find-hasAllOf: " + ds.find(User.class).field("age").hasAllOf(ageList).asList());
    //inprint("find-hasAnyOf: " + ds.find(User.class).field("age").hasAnyOf(ageList).asList());
    //not inprint("find-hasNoneOf: " + ds.find(User.class).field("age").hasNoneOf(ageList).asList());
    //elemMatch    //print("find-hasThisElement: " + ds.find(User.class).field("age").hasThisElement(55).asList());print("find-hasThisOne: " + ds.find(User.class).field("age").hasThisOne(55).asList());
print("find-in: " + ds.find(User.class).field("age").in(ageList).asList());
print("find-lessThan: " + ds.find(User.class).field("age").lessThan(20).asList());
print("find-lessThanOrEq: " + ds.find(User.class).field("age").lessThanOrEq(18).asList());
    //print("find-lessThanOrEq: " + ds.find(User.class).field("age").near(.2, .8).asList());print("find: " + ds.find(User.class, "id", 1306813979609L).get());
print("find: " + ds.find(User.class, "age", 28, 1, 2).asList());
print("findAndDelete: " + ds.findAndDelete(ds.createQuery(User.class).field("id").equal(1306813979609L)));
print("find: " + ds.find(User.class).asList());
}
4、 Query查询操作
/** * <b>function:</b> query查询 * @author hoojo * @createDate 2012-2-16 下午10:40:10 */@Test
public void testQuery() {
    // 查询所有print("query: " + ds.createQuery(User.class).asList());
    // 查询主键print("query key: " + ds.createQuery(User.class).asKeyList());
    // 结果集数量print("query: " + ds.createQuery(User.class).countAll());
    // 抓取查询所有记录    Iterable<User> it = ds.createQuery(User.class).fetch();    while(it.iterator().hasNext()) {        print("fetch: " + it.iterator().next());}
    // null     it = ds.createQuery(User.class).fetchEmptyEntities();    while(it.iterator().hasNext()) {        print("fetchEmptyEntities: " + it.iterator().next());}
    // all key    Iterable<Key<User>> itkeys = ds.createQuery(User.class).fetchKeys();    while(itkeys.iterator().hasNext()) {        print("fetchKeys: " + itkeys.iterator().next());}
    // age > 24print("query: " + ds.createQuery(User.class).filter("age > ", 24).asList());
    // age in (20, 28)print("query: " + ds.createQuery(User.class).filter("age in ", newint[] { 20, 28 }).asList());
    // limit 3print("query: " + ds.createQuery(User.class).limit(3).asList());
    // 分页类似MySQLprint("query: " + ds.createQuery(User.class).offset(11).limit(5).asList());
    // order排序,默认ascprint("query: " + ds.createQuery(User.class).order("age").asList());
    //descprint("query: " + ds.createQuery(User.class).order("-age").asList());
    // 组合排序 order by age, nameprint("query: " + ds.createQuery(User.class).order("age, name").asList());
print("query: " + ds.createQuery(User.class).queryNonPrimary().asList());
print("query: " + ds.createQuery(User.class).queryPrimaryOnly().asList());
    //如果include 为true就表示取该属性的值,其他的默认null,反之为false则该属性为null,取其他的值print("query: " + ds.createQuery(User.class).retrievedFields(false, "age").asList());
}
5、 get和count查询
/** * <b>function:</b> get查询 * @author hoojo * @createDate 2012-2-16 下午10:39:09 */@Test
public void testGet() {
    User user = new User();user.setId(1306916670518L);
    print("get: " + ds.get(user));    List<Long> ids = new ArrayList<Long>();ids.add(1306907246519L);
ids.add(1306916670524L);
    // 通过id集合查询相当于in ()print("get: " + ds.get(User.class, ids).asList());
    // id查询print("get: " + ds.get(User.class, 1306916670524L));
}
/** * <b>function:</b> count查询 * @author hoojo * @createDate 2012-2-16 下午10:38:02 */@Test
public void testGetCount() {
    User user = new User();user.setId(1306916670518L);
    print("getCount: " + ds.getCount(user));print("getCount: " + ds.getCount(User.class));
    List<Long> ids = new ArrayList<Long>();ids.add(1306907246519L);
ids.add(1306916670524L);
print("getCount: " + ds.getCount(ds.get(User.class, ids)));
    // age > 22的记录print("getCount: " + ds.getCount(ds.createQuery(User.class).filter("age > ", 22)));
    // 所有print("countAll: " + ds.get(User.class, ids).countAll());
print("countAll: " + ds.find(User.class).countAll());
}
6、 其他操作
@Test
public void testOthers() {
query();
    /** 索引 */ds.ensureIndexes();
    // 同时用annotation也可以给指定的属性建立索引    // 只需用在JavaEntity建立索引的属性上添加annotation    /*@Indexed(value = IndexDirection.ASC, name = "address_index")    String address;    // 建立唯一索引    @Indexed(value = IndexDirection.ASC, name = "bandName", unique = true)    String name;*/ds.ensureCaps();
    User user = new User();user.setId(1306916670518L);
    print("getDB: " + ds.getDB());    print("getDefaultWriteConcern: " + ds.getDefaultWriteConcern());print("DBColl: " + ds.getCollection(User.class)); // 查询User对象对应的集合
    Key<User> key = ds.getKey(user); // 主键    print("getKey: " + key);print("exists: " + ds.exists(user)); //是否存在该对象
    print("exists: " + ds.exists(ds.getKey(user)));print("getByKey: " + ds.getByKey(User.class, key));
    List<Key<User>> keys = new ArrayList<Key<User>>();keys.add(key);
user.setId(1306916670521L);
keys.add(ds.getKey(user));
    print("getByKey: " + ds.getByKeys(keys));print("getByKey: " + ds.getByKeys(User.class, keys));
query();
}
用Morphia操作对象相对比较简单,它对MongoDB对Java的操作进行了一些封装,特别是查询这方面的。有没有感觉像是在用Hibernate?
