Java 深入浅出讲解代理模式

static Object newProxyInstance(ClassLoader loader, Class[] interfaces,InvocationHandler h):

public interface Moveable {

     void move();

}

//实现Moveable 接口，并随机暂停一段时间

import java.util.Random;

public class Car implements Moveable{

     @Override

     public void move() {

         try {

             Thread.sleep( new Random().nextInt( 1000 ));

             System.out.println( "汽车行驶中" );

         } catch (InterruptedException e) {

             e.printStackTrace();

         }

     }

}

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Method;

public class TimeHandler implements InvocationHandler{

     public TimeHandler(Object target){

         super ();

         this .target = target;

     }

     private Object target;

     /**

      *

      * @param proxy :被代理的对象

      * @param method：被代理对象的方法

      * @param args：方法的参数

      * @return

      * @throws Throwable

      * 返回值：Object 方法的返回值

      */

     @Override

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

         long startTime = System.currentTimeMillis();

         System.out.println( "汽车开始行使" );

         method.invoke(target);

         long endTime = System.currentTimeMillis();

         System.out.println( "汽车行驶结束，行驶的时间为：" +(endTime-startTime)+ "毫秒" );

         return null ;

     }

}

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Proxy;

public class Test {

     public static void main(String[] args) {

         Car car = new Car();

         InvocationHandler h = new TimeHandler(car);

         Class<?> cls = car.getClass();

         /**

          * newProxyInstanced的参数

          * 分别是：类加载器、实现的接口、实现的处理器

          */

         Moveable m = (Moveable) Proxy.newProxyInstance(cls.getClassLoader(),

                 cls.getInterfaces(),h);

         m.move();

     }

}