动态代理的工厂实现

动态代理的角色及其原理，见下文：
http://tiro-li.iteye.com/blog/1901678

动态代理的工厂类：DynamicProxyFactory.java

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

public class DynamicProxyFactory implements InvocationHandler
{
	//被代理的对象
	private Object proxyObj;
	
	private DynamicProxyFactory(Object obj)
	{
		this.proxyObj = obj;
	}
	
	//生成动态代理对象的工厂方法
	public static Object factory(Object obj)
	{
		return Proxy.newProxyInstance(obj.getClass().getClassLoader(),obj.getClass().getInterfaces(),new DynamicProxyFactory(obj));
	}
	
	@Override
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
	{
		//使用反射调用被代理对象的方法
		return method.invoke(proxyObj,args);
	}
}

测试类：Test.java

import java.util.ArrayList;
import java.util.List;

public class Test
{
	public static void main(String[] args)
	{
		List<String> list = (List<String>)DynamicProxyFactory.factory(new ArrayList<String>());
		
		list.add("hello");
		list.add("world");
		
		System.out.println(list);
	}
}