NoSQL 之 Morphia 操作 MongoDB

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NoSQL 之 Morphia 操作 MongoDB

2012-02-17 13:49:26 我来说两句

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上文章 http://www.2cto.com/database/201202/119911.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

http://hoojo.cnblogs.com/

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DBObject
DBObject 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","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",new BasicDBObject( "etc","idx" )); // 创建唯一索引 coll.ensureIndex(new BasicDBObject("emial",new BasicDBObject("unique",false)); // 创建索引，指定索引名称default_index coll.ensureIndex(new BasicDBObject("address",new BasicDBObject( "name","default_index")); // 创建索引对象，索引名称user_index coll.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DBObject print("toDBObject: " + morphia.toDBObject(new User(System.currentTimeMillis(),"jackson",true,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(),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(),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","china-gz")); User user = new User(System.currentTimeMillis() + 3,"zhaoliu",29,"china-beijin"); users.add(user); users.add(new User(System.currentTimeMillis() + 6,"wangwu",24,"china-shanghai")); users.add(new User(System.currentTimeMillis() + 9,"lisi",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,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,uo).getUpdatedCount()); print("update: " + ds.update(ds.createQuery(User.class).field("id").equal(1306907246518L),uo).getUpdatedCount()); print("update: " + ds.update(ds.find(User.class,1306907246518L),uo).getUpdatedCount()); uo = ds.createUpdateOperations(User.class); uo.set("name","zhaoqq").set("age","fzz"); print("update: " + ds.update(ds.find(User.class,1306907246518L).get(),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),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()); //like print("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 > 48 print("find-greaterThan: " + ds.find(User.class).field("age").greaterThan(66).asList()); //age >= 48 print("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); //all print("find-hasAllOf: " + ds.find(User.class).field("age").hasAllOf(ageList).asList()); //in print("find-hasAnyOf: " + ds.find(User.class).field("age").hasAnyOf(ageList).asList()); //not in print("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,1306813979609L).get()); print("find: " + ds.find(User.class,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 > 24 print("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 3 print("query: " + ds.createQuery(User.class).limit(3).asList()); // 分页类似MySQL print("query: " + ds.createQuery(User.class).offset(11).limit(5).asList()); // order排序，默认asc print("query: " + ds.createQuery(User.class).order("age").asList()); //desc print("query: " + ds.createQuery(User.class).order("-age").asList()); // 组合排序order by age,name print("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？

（编辑：李大同）

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