理解-动态代理-设计模式

package com.hk.ztry;

public interface Subject
{
    abstract public void request();
}

 

package com.hk.ztry;

public class RealSubject implements Subject
{
    @Override  
    public void request()  
    {  
        System.out.println("这里是RealSubject类.");  
    }  
}

 

package com.hk.ztry;

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

public class DynamicSubject implements InvocationHandler  
{
    
    private Object my_subject;
    
    public DynamicSubject(Object curr_subject)
    {
        this.my_subject=curr_subject;
    }
    
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
    {
        //my_subject实际的被代理对象
        //args为执行被代理对象相应操作所需的参数
        method.invoke(my_subject, args);
        
        
        return null;
    }
}

package com.hk.ztry;

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

public class ProxyDynamicTest 
{
    //直到此刻，我才明白，动态代理这个设计模式，到底是个什么鬼。OK
    //就是让subject这个接口，来代理具体类的行为，反正这些method，接口都有的。
    public static void main(String[] args)  
    {  
        RealSubject real_subject = new RealSubject();  
        InvocationHandler invocationHandler = new DynamicSubject(real_subject);  
  
        Class realobj_class = real_subject.getClass();  
  
            Subject subject = (Subject)Proxy.newProxyInstance(
        realobj_class.getClassLoader(),  realobj_class.getInterfaces(), invocationHandler);  
            
        //由subject为real_subject执行代理
        subject.request();  
        
    }  
}