数据库连接池——JDBC通过代理模式来保持用户关闭连接的习惯

基本思想：拦截Connection的close()方法，具体做法：使用代理模式来实现

核心代码：

public class MyConnection implements Connection {
	private Connection realConnection;
	private MyDataSource myDataSource;

	MyConnection(Connection connection, MyDataSource myDataSource) {
		this.realConnection = connection;
		this.myDataSource = myDataSource;
	}
......
......
@Override
	public void close() throws SQLException {
		// TODO Auto-generated method stub
		myDataSource.getConnectionPool().addLast(this);
	}
......
......
}

使用动态代理：

/**
 * 
 */
package datasource;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;

/**
 * 
 * 2009-9-29
 * 
 * 湖南大学 计算机与通信学院 计算机科学与技术专业
 * 
 * @author 陈春晓
 * 
 */
public class MyConnectionHander implements InvocationHandler {
	private Connection realConnection = null;
	private Connection warpedConnection = null;
	private MyDataSource myDataSource = null;

	public MyConnectionHander(MyDataSource myDataSource) {
		this.myDataSource = myDataSource;
	}

	Connection bind(Connection realConn) {
		this.realConnection = realConn;
		this.warpedConnection = (Connection) Proxy.newProxyInstance(this.getClass()
				.getClassLoader(), new Class[] { Connection.class }, this);
		return warpedConnection;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
	 *      java.lang.reflect.Method, java.lang.Object[])
	 */
	@Override
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
		// TODO Auto-generated method stub
		if ("close".equals(method.getName())) {
			this.myDataSource.getConnectionPool().addLast(warpedConnection);
		}
		return method.invoke(this.realConnection, args);
	}

}

 

完整代码见附件：