连接池JAVA实现

package com.dalong.connectionpool;
import java.util. HashMap;
import java.util.Vector;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.*;
/**
*

Title:

*

Description: test

*

Copyright: Copyright (c) 2003

*

Company: home

* @author dalong
* @version 1.0
*/

public class ConnectionPool {

// 连接池的管理器,首先初始化，仅仅有一个对象，管理 连接池
private static HashMap connectionPoolManager=new HashMap();
//没有用过的 连接池，用vector实现同步
private static Vector noUseConnectionPool;
//没有用过的 连接池
private static HashMap nowUseConnectionPool;

private static String dbDriver="odbc:jdbc:OdbcJdbcDriver";
private static String dbUrl="dalong@XX";
private static String userName="dalong";
private static String userPassword="dalong";

//默认为100个 连接池
private static int MAX_POOL=100;

//singleTon 设计模式
private ConnectionPool(String driver,String url,String name,String password,int max)
throws ClassNotFoundException {
Class.forName(driver);
dbUrl=url;
userName=name;
userPassword=password;
MAX_POOL=max;
}
public static ConnectionPool getConnManagerInstance(String poolName)
throws ClassNotFoundException{
ConnectionPool tempPool=(ConnectionPool)connectionPoolManager.get(poolName);
if(tempPool==null){
tempPool=new ConnectionPool(dbDriver,dbUrl,userName,userPassword,MAX_POOL);
connectionPoolManager.put(poolName,tempPool);
return tempPool;
}else
return tempPool;
}

//通过 连接池获得真正的链接
public static Connection getConnection() throws java.sql.SQLException{
Connection conn=null;
synchronized(noUseConnectionPool){
if(noUseConnectionPool.size()>0){
conn=(Connection)noUseConnectionPool.firstElement();
noUseConnectionPool.remove(conn);
return conn;
}
}
//如果数据库 连接池没有链接了，自己创建一个
if(conn==null){
conn=createConnection(dbDriver,dbUrl,userName,userPassword);
}else if(conn.isClosed()){
nowUseConnectionPool.remove(conn);
conn=createConnection(dbDriver,dbUrl,userName,userPassword);
}
conn.setAutoCommit(false);
nowUseConnectionPool.put(conn,conn);
return conn;
}

//如果 连接池没有链接了，就需要产生一个链接
private static Connection createConnection(String driver,String url,String user,String password)
throws java.sql.SQLException{
Connection conn=DriverManager.getConnection(url,user,password);
return conn;
}
public static void releaseConnection(Connection conn,boolean isCommit)
throws java.sql.SQLException{
if(isCommit)
conn.commit();
else
conn.rollback();
nowUseConnectionPool.remove(conn);
if(noUseConnectionPool.size() + nowUseConnectionPool.size()synchronized(noUseConnectionPool){
noUseConnectionPool.add(conn);
}
}else{
conn.close();
}
}

public static void main(String[] args) {
//测试模拟10个客户
for (int i = 0; i < 10; i++) {
try {
//xxxx 一般为属性文件读取
ConnectionPool pool = ConnectionPool.getConnManagerInstance("xxxx");
Connection conn = pool.getConnection();

}catch (SQLException ex1) {
//处理异常
}
catch (ClassNotFoundException ex) {
//处理异常
}
}
}
}