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;@Beforepublic void init(){mongoClient=new MongoClient("127.0.0.1:27017");db=mongoClient.getDatabase("test");}@Testpublic 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"));}}@Testpublic void testAdd(){MongoCollection<Document> peoples=db.getCollection("people");Document doc=new Document();doc.put("name", "xiaoming");doc.put("age", 23);peoples.insertOne(doc);}@Testpublic void remove(){MongoCollection<Document> peoples=db.getCollection("people");Document doc=new Document();doc.put("name", "xiaoming");peoples.deleteMany(doc);}@Testpublic 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());}@Afterpublic void tesRelease(){if(mongoClient!=null){mongoClient.close();}}}