JAVA代码使用mongoDB对数据库进行简单的增删改查

[code]
package com.mongo.controller;

import com.mongodb.*;

import java.net.UnknownHostException;
import java.util.Date;
import java.util.Set;

/**
* Created by Cheung on 2017/12/29.
*/
public class TestController {

private static final String MONGO_HOST = "localhost";
private static final Integer MONGO_PORT = 27017;
private static final String MONGO_USERNAME = "test";
private static final String MONGO_PASSWORD = "1234";
private static final String MONGO_DB_NAME = "mongo-db-test";
private static final String MONGO_COLLECTION_NAME = "mongo-collection-test";

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

// 获取Mongo客户端
MongoClient mongoClient = new MongoClient(MONGO_HOST, MONGO_PORT);
/**
* 1.获取所有db名称并打印（mongodb未开启auth认证下可用）
*/
/*List<String> databaseNames = mongoClient.getDatabaseNames();
System.out.println(MONGO_HOST + ":" + MONGO_PORT.toString() + "包含如下数据库：");
for (String databaseName : databaseNames) {
System.out.println(databaseName);
}*/

/**
* 2.获取到指定db（若不存在，则mongo会创建该db）
*/
DB db = mongoClient.getDB(MONGO_DB_NAME);
// 2.1用户名&密码校验
boolean auth = db.authenticate(MONGO_USERNAME, MONGO_PASSWORD.toCharArray());
if (!auth) {
System.out.println(MONGO_DB_NAME + " connection failed！");
return;
}
System.out.println(MONGO_DB_NAME + " connection success！");

// 2.2获取该db下所有集合名称并打印
Set<String> collectionNames = db.getCollectionNames();
System.out.println(db.getName() + "包含如下集合：");
for (String collectionName : collectionNames) {
System.out.println(collectionName);
}

// 2.3获取指定集合(若不存在，则mongo会创建该集合)
DBCollection collection = db.getCollection(MONGO_COLLECTION_NAME);

/**
* 3.增删查改
*/
// 3.1插入一条文档
BasicDBObject document = new BasicDBObject();
document.put("name", "Cheung");
document.put("age", 24);
document.put("address", "Beijing");
document.put("date", new Date());
collection.insert(document);

// 3.2查询一条文档
BasicDBObject searchObj = new BasicDBObject();
searchObj.put("name", "Cheung");
DBCursor cursor = collection.find(searchObj);
if (cursor.hasNext()) {
System.out.println("查询到的文档为：");
while (cursor.hasNext()) {
System.out.println(cursor.next());
}
} else {
System.out.println("该文档不存在！");
}

// 3.3修改一条文档
BasicDBObject newDocument = new BasicDBObject();
newDocument.put("name", "Cheung-updated");// 新文档
BasicDBObject updateObj = new BasicDBObject();
updateObj.put("$set", newDocument);
collection.update(searchObj, updateObj);// 更新

// 3.4查询修改后的文档（修改确认）
DBCursor cursor2 = collection.find(newDocument);
if (cursor2.hasNext()) {
System.out.println("修改后的文档为：");
while (cursor2.hasNext()) {
System.out.println(cursor2.next());
}
} else {
System.out.println("该文档不存在！");
}

// 3.5删除该文档
collection.remove(newDocument);

// 3.6查询该文档是否存在（删除确认）
DBCursor cursor3 = collection.find(newDocument);
if (cursor3.hasNext()) {
System.out.println("查询到的文档为：");
while (cursor3.hasNext()) {
System.out.println(cursor3.next());
}
} else {
System.out.println("该文档不存在！");
}

}

}