MongoDB学习笔记：(3)、mongodb 3.2在java环境中的简单CRUD

首先新建一个java project项目，去下载mongo-java-driver-3.2.2.jar包。build path导入junit需要的jar包。另外运行代码前先要启动mongod 服务。下面就是简单的CRUD代码：

package com.mongodb;

import junit.framework.TestResult;

import org.bson.Document;
import org.bson.conversions.Bson;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;

public class MongoDBTest {

private MongoDatabase db=null;

private MongoClient mongoClient=null;

@Before
public void init(){
mongoClient=new MongoClient("127.0.0.1:27017");
db=mongoClient.getDatabase("test");
}

@Test
public void testQuery() {

MongoCollection<Document> collec=db.getCollection("people");
System.out.println(collec);
MongoCursor<Document> cursor=collec.find().iterator();
while(cursor.hasNext()){
Document obj=(Document)cursor.next();
System.out.println(obj.get("name")+","+obj.get("age"));
}

}

@Test
public void testAdd(){
MongoCollection<Document> peoples=db.getCollection("people");
Document doc=new Document();
doc.put("name", "xiaoming");
doc.put("age", 23);
peoples.insertOne(doc);
}

@Test
public void remove(){
MongoCollection<Document> peoples=db.getCollection("people");
Document doc=new Document();
doc.put("name", "xiaoming");
peoples.deleteMany(doc);
}

@Test
public void update(){

MongoCollection<Document> peoples=db.getCollection("people");
Document bson=new Document();
bson.put("name", "xiaoming");

Document bson1=new Document();
bson1.put("name", "xiaoming");
bson1.put("age", "26");

UpdateResult result=peoples.replaceOne(bson, bson1);//用updateOne会报错
System.out.println("修改行数:"+result.getModifiedCount());

}

@After
public void tesRelease(){

if(mongoClient!=null){
mongoClient.close();
}
}

}