JDK Dynamic Proxy

Friday, 23 April 2010 04:07

// First create the interface and its impl
// Then create the Proxy class implementing InvocationHandler interface
// create a Proxy using Proxy class static method createProxyInstance passing
// handles to classloader, interface and proxy impl.



package com.aop.one;



public interface Feather {

	

	public void color(String s);

	



}



package com.aop.one;



public class BirdFeather implements Feather{



	@Override

	public void color(String s) {

			System.out.println("The color of the feather is : " + s);

	}

	

	



}



package com.aop.one;



import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Method;

import java.lang.reflect.Proxy;



public class ProxyFeather implements InvocationHandler {



	private Object target;

	

	public ProxyFeather(Object t)

	{

		this.target = t;

	}

	

	

	@Override

	public Object invoke(Object proxy, Method method, Object[] args)

			throws Throwable {

		

		  System.out.println("Before testing for the colors of the feathers");	

		  method.invoke(target, args);

		  System.out.println("After testing for the colors of the feathers");

		  return null;	 

	}



	public static Object createProxy(Object t)

	{

		return Proxy.newProxyInstance(t.getClass().getClassLoader(),

				                      t.getClass().getInterfaces(), 

				                      new ProxyFeather(t));

	}

 

	public void setTarget(Object target) {

		this.target = target;

	}



}





package com.aop.one;



public class Tester {

	

	

	public static void main(String[] args) {

		

		Feather f = new BirdFeather();

		Feather myProxy = (Feather)ProxyFeather.createProxy(f);

		myProxy.color("Violet");

		

		

	}



}