【MongoDB for Java】Java操作MongoDB数据库

Mongo mongo = new Mongo();

DB db = mongo.getDB([test]);

DBCursor cur = users.find();

while (cur.hasNext()) {

System.out.println(cur.next());

}

package com.hoo.test;

import java.net.UnknownHostException;

import com.mongodb.DB;

import com.mongodb.DBCollection;

import com.mongodb.DBCursor;

import com.mongodb.Mongo;

import com.mongodb.MongoException;

import com.mongodb.util.JSON;

/**

  * <b>function:</b>MongoDB 简单示例

  * @author hoojo

  * @createDate 2011-5-24 下午02:42:29

  * @file SimpleTest.java

  * @package com.hoo.test

  * @project MongoDB

  * @blog http://blog.csdn.net/IBM_hoojo

  * @email hoojo_@126测试数据

  * @version 1.0

  */

public class SimpleTest {

  public static void main(String[] args) throws UnknownHostException, MongoException {

   Mongo mg = new Mongo();

   //查询所有的Database

   for (String name : mg.getDatabaseNames()) {

    System.out.println( "dbName: " + name);

   }

   DB db = mg.getDB( "test" );

   //查询所有的聚集集合

   for (String name : db.getCollectionNames()) {

    System.out.println( "collectionName: " + name);

   }

   DBCollection users = db.getCollection( "users" );

   //查询所有的数据

   DBCursor cur = users.find();

   while (cur.hasNext()) {

    System.out.println(cur.next());

   }

   System.out.println(cur.count());

   System.out.println(cur.getCursorId());

   System.out.println(JSON.serialize(cur));

  }

}

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CRUD操作

  * @author hoojo

  * @createDate 2011-6-2 下午03:21:23

  * @file MongoDB4CRUDTest.java

  * @package com.hoo.test

  * @project MongoDB

  * @blog http://blog.csdn.net/IBM_hoojo

  * @email hoojo_@126测试数据

  * @version 1.0

  */

public class MongoDB4CRUDTest {

  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);

  }

}

/**

  * <b>function:</b> 查询所有数据

  * @author hoojo

  * @createDate 2011-6-2 下午03:22:40

  */

private void queryAll() {

  print( "查询users的所有数据：" );

  //db游标

  DBCursor cur = users.find();

  while (cur.hasNext()) {

   print(cur.next());

  }

}

@Test

public void add() {

  //先查询所有数据

  queryAll();

  print( "count: " + users.count());

  DBObject user = new BasicDBObject();

  user.put( "name" , "hoojo" );

  user.put( "age" , 24 );

  //users.save(user)保存，getN()获取影响行数

  //print(users.save(user).getN());

  //扩展字段，随意添加字段，不影响现有数据

  user.put( "sex" , "男" );

  print(users.save(user).getN());

  //添加多条数据，传递Array对象

  print(users.insert(user, new BasicDBObject( "name" , "tom" )).getN());

  //添加List集合

  List<DBObject> list = new ArrayList<DBObject>();

  list.add(user);

  DBObject user2 = new BasicDBObject( "name" , "lucy" );

  user.put( "age" , 22 );

  list.add(user2);

  //添加List集合

  print(users.insert(list).getN());

  //查询下数据，看看是否添加成功

  print( "count: " + users.count());

  queryAll();

}

@Test

public void remove() {

  queryAll();

  print( "删除id = 4de73f7acd812d61b4626a77：" + users.remove( new BasicDBObject( "_id" , new ObjectId( "4de73f7acd812d61b4626a77" ))).getN());

  print( "remove age >= 24: " + users.remove( new BasicDBObject( "age" , new BasicDBObject( "$gte" , 24 ))).getN());

}

@Test

public void modify() {

  print( "修改：" + users.update( new BasicDBObject( "_id" , new ObjectId( "4dde25d06be7c53ffbd70906" )), new BasicDBObject( "age" , 99 )).getN());

  print( "修改：" + users.update(

    new BasicDBObject( "_id" , new ObjectId( "4dde2b06feb038463ff09042" )),

    new BasicDBObject( "age" , 121 ),

    true , //如果数据库不存在，是否添加

    false //多条修改

    ).getN());

  print( "修改：" + users.update(

    new BasicDBObject( "name" , "haha" ),

    new BasicDBObject( "name" , "dingding" ),

    true , //如果数据库不存在，是否添加

    true //false只修改第一天，true如果有多条就不修改

    ).getN());

  //当数据库不存在就不修改、不添加数据，当多条数据就不修改

  //print("修改多条：" + coll.updateMulti(new BasicDBObject("_id", new ObjectId("4dde23616be7c19df07db42c")), new BasicDBObject("name", "199")));

}

@Test

public void query() {

  //查询所有

  //queryAll();

  //查询id = 4de73f7acd812d61b4626a77

  print( "find id = 4de73f7acd812d61b4626a77: " + users.find( new BasicDBObject( "_id" , new ObjectId( "4de73f7acd812d61b4626a77" ))).toArray());

  //查询age = 24

  print( "find age = 24: " + users.find( new BasicDBObject( "age" , 24 )).toArray());

  //查询age >= 24

  print( "find age >= 24: " + users.find( new BasicDBObject( "age" , new BasicDBObject( "$gte" , 24 ))).toArray());

  print( "find age <= 24: " + users.find( new BasicDBObject( "age" , new BasicDBObject( "$lte" , 24 ))).toArray());

  print( "查询age!=25：" + users.find( new BasicDBObject( "age" , new BasicDBObject( "$ne" , 25 ))).toArray());

  print( "查询age in 25/26/27：" + users.find( new BasicDBObject( "age" , new BasicDBObject(QueryOperators.IN, new int [] { 25 , 26 , 27 }))).toArray());

  print( "查询age not in 25/26/27：" + users.find( new BasicDBObject( "age" , new BasicDBObject(QueryOperators.NIN, new int [] { 25 , 26 , 27 }))).toArray());

  print( "查询age exists 排序：" + users.find( new BasicDBObject( "age" , new BasicDBObject(QueryOperators.EXISTS, true ))).toArray());

  print( "只查询age属性：" + users.find( null , new BasicDBObject( "age" , true )).toArray());

  print( "只查属性：" + users.find( null , new BasicDBObject( "age" , true ), 0 , 2 ).toArray());

  print( "只查属性：" + users.find( null , new BasicDBObject( "age" , true ), 0 , 2 , Bytes.QUERYOPTION_NOTIMEOUT).toArray());

  //只查询一条数据，多条去第一条

  print( "findOne: " + users.findOne());

  print( "findOne: " + users.findOne( new BasicDBObject( "age" , 26 )));

  print( "findOne: " + users.findOne( new BasicDBObject( "age" , 26 ), new BasicDBObject( "name" , true )));

  //查询修改、删除

  print( "findAndRemove 查询age=25的数据，并且删除: " + users.findAndRemove( new BasicDBObject( "age" , 25 )));

  //查询age=26的数据，并且修改name的值为Abc

  print( "findAndModify: " + users.findAndModify( new BasicDBObject( "age" , 26 ), new BasicDBObject( "name" , "Abc" )));

  print( "findAndModify: " + users.findAndModify(

   new BasicDBObject( "age" , 28 ), //查询age=28的数据

   new BasicDBObject( "name" , true ), //查询name属性

   new BasicDBObject( "age" , true ), //按照age排序

   false , //是否删除，true表示删除

   new BasicDBObject( "name" , "Abc" ), //修改的值，将name修改成Abc

   true ,

   true ));

  queryAll();

}

public void testOthers() {

  DBObject user = new BasicDBObject();

  user.put( "name" , "hoojo" );

  user.put( "age" , 24 );

  //JSON 对象转换 

  print( "serialize: " + JSON.serialize(user));

  //反序列化

  print( "parse: " + JSON.parse( "{ \"name\" : \"hoojo\" , \"age\" : 24}" ));

  print( "判断temp Collection是否存在: " + db.collectionExists( "temp" ));

  //如果不存在就创建

  if (!db.collectionExists( "temp" )) {

   DBObject options = new BasicDBObject();

   options.put( "size" , 20 );

   options.put( "capped" , 20 );

   options.put( "max" , 20 );

   print(db.createCollection( "account" , options));

  }

  //设置db为只读

  db.setReadOnly( true );

  //只读不能写入数据

  db.getCollection( "test" ).save(user);

}