JDK Dynamic Proxy

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        // 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");
		
		
	}

}

Tags:
• java
• proxy