ProxyPattern_代理模式

1:此例演示 使用JDK代理模式,使用此模式须实现接口,对没有实现接口的类的代理可以用 CGLIB代理

package cn.proxy.test;

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

/**
 * 代理模式(使用JDKProxy代理)
 */
public class ProxyClass implements InvocationHandler {
	
	private RealInterface realInterface; // 实际被调用对象
	private RealInterface warpedInterface; // 经包装过的代理对象
	
	RealInterface bind(RealInterface realInterface){
		this.realInterface = realInterface;
		// 生成代理对象
		this.warpedInterface = (RealInterface)Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class[]{RealInterface.class}, this);
		return warpedInterface;
	}

	// 将对实际接口的调用转发给 实现InvocationHandler的类
	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		// 拦截方法
		if("sayHello".equals(method.getName())){
			return "sayHello 被拦截...";
		}
		return method.invoke(realInterface, args);
	}
	
	public static void main(String[] args) {
		ProxyClass instance = new ProxyClass();
		RealInterface proxyInstance = instance.bind(new InterfaceInstance());
		System.out.println(proxyInstance.sayHello("lisi"));
		System.out.println(proxyInstance.sayHi("wangwu"));
	}

}

interface RealInterface {
	
	public String sayHello(String name);
	
	public String sayHi(String name);

}

class InterfaceInstance implements RealInterface {

	@Override
	public String sayHello(String name) {
		return name + " sayHello....";
	}

	@Override
	public String sayHi(String name) {
		return name + " sayHi....";
	} 
	
}