动态代理实例——增强Waiter接口

Dear 丶 2021-06-22 15:37 330阅读 0赞

## 图示 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ1NjUxMjc_size_16_color_FFFFFF_t_70]

## 代码 ##

### Waiter接口 ###

/* * 服务员接口 */
    public interface Waiter { 
    	// 服务方法
    	public void serve();
    
    }

### ManWaiter类 ###

public class ManWaiter implements Waiter { 
    
    	public void serve() { 
    		System.out.println("服务中...");
    	}
    
    }

### Demo ###

package com.veeja.demo2;
    
    import java.lang.reflect.InvocationHandler;
    import java.lang.reflect.Method;
    import java.lang.reflect.Proxy;
    
    import org.junit.Test;
    
    public class Demo2 { 
    
    	@Test
    	public void fun1() { 
    		Waiter manWaiter = new ManWaiter();
    		// 创建三大参数
    		ClassLoader loader = this.getClass().getClassLoader();
    		Class[] interfaces = {  Waiter.class };
    		// 参数manWaiter表示目标对象
    		InvocationHandler h = new WaiterInvocationHandler(manWaiter);
    
    		// 得到代理对象，代理对象就是在目标对象的基础上进行了增强的对象
    		Waiter waiterProxy = (Waiter) Proxy.newProxyInstance(loader,
    				interfaces, h);
    		// 前面增加你好，后面添加再见。
    		waiterProxy.serve();
    	}
    }
    
    class WaiterInvocationHandler implements InvocationHandler { 
    
    	private Waiter waiter;// 创建目标对象
    
    	public WaiterInvocationHandler(Waiter waiter) { 
    		this.waiter = waiter;
    
    	}
    
    	public Object invoke(Object proxy, Method method, Object[] args)
    			throws Throwable { 
    
    		System.out.println("您好！");
    		this.waiter.serve();// 调用目标对象的目标方法
    		System.out.println("再见！");
    		return null;
    	}
    
    }

--------------------

END.

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ1NjUxMjc_size_16_color_FFFFFF_t_70]: /images/20210615/25a17455cb3e4daa8f2ed87286162a28.png