NoSQL 之 Morphia 操作 MongoDB
上两篇文章:http://www.iyunv.com/hoojo/archive/2011/06/01/2066426.htmlhttp://www.iyunv.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
Email：hoojo_@126.com
Blog：http://blog.iyunv.com/IBM_hoojo
http://hoojo.iyunv.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; /** * function: 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.iyunv.com/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", "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; /** * function: 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.iyunv.com/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */publicclass BasicDBObjectUtils { public static 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; /** * function: 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.iyunv.com/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
/** * function: 测试Collection的index相关操作 * @author hoojo * @createDate 2012-2-16 下午08:32:26 */@Testpublic 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_index coll.ensureIndex(new BasicDBObject("address", 1), 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; /** * function: 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.iyunv.com/IBM_hoojo * @email hoojo_@126.com * @version 1.0 *///利用morphia的annotation进行注解@Entitypublic 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; /** * function: 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.iyunv.com/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()); } } /** * function: 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, 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)); } /** * function: 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)))); } /** * function: 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; /** * function: 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.iyunv.com/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()); } } /** * function: 查询所有 * @author hoojo * @createDate 2012-2-16 下午10:36:13 */ private void query() { Iterable 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
/** * function: CUD增删改 * @author hoojo * @createDate 2012-2-16 下午10:46:08 */@Testpublic 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 users = new ArrayList(); 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 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
/** * function: find查询 * @author hoojo * @createDate 2012-2-16 下午10:45:55 */@Testpublic 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 ageList = new ArrayList(); 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, "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
/** * function: query查询 * @author hoojo * @createDate 2012-2-16 下午10:40:10 */@Testpublic 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 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 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
/** * function: get查询 * @author hoojo * @createDate 2012-2-16 下午10:39:09 */@Testpublic void testGet() { User user = new User(); user.setId(1306916670518L); print("get: " + ds.get(user)); List ids = new ArrayList(); 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));} /** * function: count查询 * @author hoojo * @createDate 2012-2-16 下午10:38:02 */@Testpublic void testGetCount() { User user = new User(); user.setId(1306916670518L); print("getCount: " + ds.getCount(user)); print("getCount: " + ds.getCount(User.class)); List ids = new ArrayList(); 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
@Testpublic 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 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 keys = new ArrayList(); 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？
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