pooledcon.java

一个仿qq的程序源码 一个用纯java开发的

package qianqian.pooledb;

import java.sql.Connection;

import qianqian.p2pchat.constant.Const;

public class PooledCon {
	// 连接数组
	private static final Connection[] pool = new Connection[Const.PoolSize];
	// 标示连接状态数组
	private static final byte[] isConUse = new byte[Const.PoolSize];
	// 连接池单例对象
	private static PooledCon poolCon = null;

	// 初始化连接池
	private PooledCon() throws java.sql.SQLException {
		for (int i = 0; i < pool.length; i++) {
			pool[i] = DBManager.getConnection();
			isConUse[i] = 0;
		}
	}

	// 实例化连接池
	public static PooledCon getInstance() throws java.sql.SQLException {
		if (poolCon == null) {
			synchronized (PooledCon.class) {
				if (poolCon == null)
					poolCon = new PooledCon();
			}
		}
		return poolCon;
	}

	// 从池中获取连接
	public Connection getCon() throws java.sql.SQLException {
		synchronized (poolCon) {
			for (int i = 0; i < pool.length; i++) {
				if (isConUse[i] == 0) {
					if (pool[i].isClosed())
						pool[i] = DBManager.getConnection();
					isConUse[i] = 1;
					return pool[i];
				}
			}
		}
		return DBManager.getConnection();
	}

	// 释放连接
	public void releaseCon(Connection con) throws java.sql.SQLException {
		for (int i = 0; i < pool.length; i++) {
			if (con == pool[i]) {
				isConUse[i] = 0;
				return;
			}
		}
		con.close();
	}

	// 关闭连接池
	public void closePool() throws java.sql.SQLException {
		if (poolCon == null)
			return;
		for (int i = 0; i < pool.length; i++) {
			if (!pool[i].isClosed())
				pool[i].close();
			isConUse[i] = 1;
		}
		poolCon = null;
	}
}