单例模式的使用

package com.voice.mongodb;

import java.net.UnknownHostException;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.Mongo;
import com.mongodb.MongoException;
import com.mongodb.WriteConcern;

public class MongoDB {

private Mongo wMongodb;

private static MongoDB instance = null;

private static synchronized MongoDB GetInstance()
{
if(instance == null)
{
instance = new MongoDB();
}
return instance;
}

private MongoDB()
{
try {
// wMongodb = new Mongo("172.16.10.15", 27020);
wMongodb = new Mongo("wmongo.olavoice.com", 27020);

wMongodb.getMongoOptions().autoConnectRetry = true;

DB db = wMongodb.getDB("olacloud");
// DB db = wMongodb.getDB("olacloud_internal");
db.authenticate("olacloud", "olacloud".toCharArray());
db.setWriteConcern(WriteConcern.SAFE);


} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (MongoException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

/**
* 获取数据库连接
* @return 已经连接的数据库
*/
public static DB getDB() {
DB db = MongoDB.GetInstance().wMongodb.getDB("olacloud");
// DB db = MongoDB.GetInstance().wMongodb.getDB("olacloud_internal");
return db;
}

/**
* 获取table的连接
* @param tableName table名
* @return table连接
*/
public static DBCollection getDBCollection(String tableName) {
DB db = MongoDB.getDB();
DBCollection col = db.getCollection(tableName);
return col;
}

/**
* 关闭当前的Mongodb连接
*/
public static void close() {
if (instance != null) {
instance.wMongodb.close();
}
}



}

单例模式的使用,布布扣,bubuko.com

单例模式的使用

原文：http://www.cnblogs.com/Wen-yu-jing/p/3783430.html