Java MongoDB 增删改查

<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongo-java-driver</artifactId>
<version>2.11.3</version>
</dependency>

package org.mongodb;

import com.mongodb.*;

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

/**
* @author: JohnLiu
*/
public class MongoDBClient {

MongoClient mongo = null;

public MongoDBClient(){
try {
mongo = new MongoClient("localhost", 27017);
} catch (UnknownHostException e) {
e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
}
if(mongo != null){
DB db = mongo.getDB("manager_db");
//authenticate the user
System.out.println("auth user 'admin/123456'" +db.authenticate("admin", "123456".toCharArray()));
//display all the dbs
List<String> dbList = mongo.getDatabaseNames();
System.out.println("-----------------show dbs--------------------");
for(String dbName: dbList){
System.out.println(dbName);
}
/**
DB db = mongo.getDB("testdb");
DBCollection table = db.getCollection("user");
Display all collections from selected database.

DB db = mongo.getDB("testdb");
Set<String> tables = db.getCollectionNames();

for(String coll : tables){
System.out.println(coll);
}
*/

}
}

public void insert(){
DB db = mongo.getDB("manager_db");
DBCollection table = db.getCollection("user");
BasicDBObject document = new BasicDBObject();
document.put("name", "John Nash");
document.put("age", 26);
document.put("createdDate", new Date());
table.insert(document);
System.out.println("insert successfully..." );
}

public void update(){
DB db = mongo.getDB("manager_db");
DBCollection table = db.getCollection("user");

BasicDBObject query = new BasicDBObject();
query.put("name", "John Nash");

BasicDBObject newDocument = new BasicDBObject();
newDocument.put("name", "John Liu");

BasicDBObject updateObj = new BasicDBObject();
updateObj.put("$set", newDocument);

table.update(query, updateObj);
System.out.println("update successfully..." );
}

public void query(){
DB db = mongo.getDB("manager_db");
DBCollection table = db.getCollection("user");

BasicDBObject searchQuery = new BasicDBObject();
searchQuery.put("name", "John Liu");

DBCursor cursor = table.find(searchQuery);

while (cursor.hasNext()) {
System.out.println(cursor.next());
}
System.out.println("query successfully..." );
}

public void remove(){
DB db = mongo.getDB("manager_db");
DBCollection table = db.getCollection("user");

BasicDBObject searchQuery = new BasicDBObject();
searchQuery.put("name", "John Liu");

table.remove(searchQuery);
System.out.println("remove successfully..." );
}
public static void main(String []args){
MongoDBClient mongoDBClient = new MongoDBClient();
mongoDBClient.insert();//insert one document to user table
mongoDBClient.update();
mongoDBClient.query();
mongoDBClient.remove();
}
}