Java操作MongoDB之CRUD（增删改查）

http://blog.csdn.net/rjfxd/article/details/12110025

 

一、准备工作

1、建立maven项目，添加所需依赖

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongo-java-driver</artifactId>
<version>2.11.3</version>
</dependency>

当然也可以建立java project，下载mongoDB对Java支持的驱动包，然后拷贝jar文件到lib下

2、开启mongo服务，建立测试类进行测试

二、完整源码如下：

 

package com.shxt.mongo;

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.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoClient;
import com.mongodb.util.JSON;

 /**
  * MongDB之CRUD
  * @author 范晓东
  * @ClassName: TestMongo
  * @Version 1.0
  * @ModifiedBy
  * @Copyright shxt
  * @date 2013-9-27 下午08:21:49
  * @description
  */
public class TestMongo {

    private Mongo mg = null;
    private DB db;
    private DBCollection users;

    @Before
    public void setUp() throws UnknownHostException {
        // 创建一个MongoDB的数据库连接对象
        mg=new MongoClient("localhost", 27017);
        //验证模式登录(如果不设置验证模块，可直接登录)
        //想要登录验证模块生效,需在命令行下输入1->mongo 2->use admin 3->db.addUser("root","root123"); 4->db.auth("root","root123");
        DB admin=mg.getDB("admin");
        boolean bool =admin.authenticate("root", "root123".toCharArray());
        if (bool){
            //login success
            //获得一个test的数据库，如果该数据库不存在，会自动创建
            db=mg.getDB("test");
        }
        // 获取一个聚集集合DBCollection,相当于我们的数据库表
        users = db.getCollection("users");
    }

    @Test
    public void testQuery() {
        //查询所有的数据库
        for (String name : mg.getDatabaseNames()) {
            System.out.println("dbName: " + name);
        }
        //查询所有的聚集集合
        for (String name : db.getCollectionNames()) {
            System.out.println("collectionName: " + name);
        }
        //查询所有的数据
        DBCursor cur = users.find();
        while (cur.hasNext()) {
            System.out.println(cur.next());
        }
        //其它
        System.out.println(cur.count());
        System.out.println(users.count());
        System.out.println(cur.getCursorId());
        System.out.println(JSON.serialize(cur));//JSON对象转换
    }

    @Test
    public void testQuery2(){
        //根据id查询
        List<DBObject> list=users.find(new BasicDBObject("_id", new ObjectId("5243871a0609f38c8a7a5ccd"))).toArray();
        System.out.println(list.get(0).get("name"));

        //根据age查询，从第一条开始取，取3条数据
        BasicDBObject user = new BasicDBObject();
        user.put("age", new BasicDBObject("$gte", 20));
        DBCursor cur=users.find(user).skip(0).limit(3);
        System.out.println(cur.count());
        while (cur.hasNext()) {
            System.out.println(cur.next());
        }

        //查询age!=25
        //users.find(new BasicDBObject("age", new BasicDBObject("$ne", 25))).toArray();
        //查询age in 25/26/27
        //users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.IN, new int[] { 25, 26, 27 }))).toArray();
        //查询age not in 25/26/27
        //users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.NIN, new int[] { 25, 26, 27 }))).toArray();
        //查询存在age的数据
        //users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.EXISTS, true))).toArray();
        //只查询age属性
        //users.find(null, new BasicDBObject("age", true)).toArray();

        //只查询一条数据，多条取第一条
        //users.findOne();
        //users.findOne(new BasicDBObject("age", 26));
        //users.findOne(new BasicDBObject("age", 26), new BasicDBObject("name", true));

        //查询age=25的数据并删除
        //users.findAndRemove(new BasicDBObject("age", 25));
        //查询age=26的数据，并且修改name的值为abc
        //users.findAndModify(new BasicDBObject("age", 26), new BasicDBObject("name", "abc"));
    }

    @Test
    public void testAdd() {
        DBObject user = new BasicDBObject();
        user.put("name", "fxd");
        user.put("age", 21);
        user.put("sex", "男");
        users.save(user);
        //查看是否添加成功
        DBCursor cur = users.find();
        while (cur.hasNext()) {
            System.out.println(cur.next());
        }
    }

    @Test
    public void testAdd2() {
        DBObject user1 = new BasicDBObject("name","张三");
        DBObject user2 = new BasicDBObject("age",20);
        users.insert(user1,user2);
        //查看是否添加成功
        DBCursor cur = users.find();
        while (cur.hasNext()) {
            System.out.println(cur.next());
        }
    }

    @Test
    public void testAdd3() {
        DBObject user1 = new BasicDBObject("name","张三");
        DBObject user2 = new BasicDBObject("age",20);
        List<DBObject> list = new ArrayList<DBObject>();
        list.add(user1);
        list.add(user2);
        users.insert(list);
        //查看是否添加成功
        DBCursor cur = users.find();
        while (cur.hasNext()) {
            System.out.println(cur.next());
        }
    }

    @Test
    public void testRemove(){
        users.remove(new BasicDBObject("_id", new ObjectId("524378680609ad5717421c6a")));
        //users.remove(new BasicDBObject("age", new BasicDBObject("$gte", 24)));
    }

    @Test
    public void update(){
         //=update users set age=17 where name='fxd';
         users.update(
              new BasicDBObject("name","fxd"),//new BasicDBObject().append("name","fxd"),
              new BasicDBObject("$set" ,new BasicDBObject("age",17)),
              false,//如果users中不存在age字段，是否更新，false表示不更新
              false//只修改第一条，true表示修改多条
         );
    }

    @Test
    public void update2(){
         //批量修改，也可以用users.update(),把第四个参数改为true即可
         //=update users set age=age+10 where name='fxd';
         users.updateMulti(
              new BasicDBObject().append("name","fxd"),
              new BasicDBObject("$inc",new BasicDBObject("age", 10))
        );
    }

    @After
    public void tearDown() {
        if (mg != null) {
            if (db != null) {
                // 结束Mongo数据库的事务请求
                try {
                    db.requestDone();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            try {
                mg.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            mg = null;
            db = null;
        }
    }
}

参考：

http://www.cnblogs.com/hoojo/archive/2011/06/02/2068665.html