spring-动态代理

package com.wyl.demo02;

public interface UserServlet {
    public void select();
    public void delete();
    public void update();
    public void insert();
}

package com.wyl.demo02;

public class UserServletImpl implements UserServlet {
    @Override
    public void select() {
        System.out.println("查询了一个用户");
    }

    @Override
    public void delete() {
        System.out.println("删除了一个用户");
    }

    @Override
    public void update() {
        System.out.println("修改了一个用户");
    }

    @Override
    public void insert() {
        System.out.println("添加了一个用户");
    }
}

package com.wyl.demo04;



import com.wyl.demo03.Rent;

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

//用这个类自动生成代理类
public class ProxyInvocationHandler implements InvocationHandler {
    //被代理的接口
    private Object object;

    public void setObject(Object object) {
        this.object = object;
    }

    //生成代理类
    public Object getProxy(){
       return Proxy.newProxyInstance(this.getClass().getClassLoader(),
               object.getClass().getInterfaces(), this);
    }
    //处理代理实例返回结果
    @Override
    public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
        log(method.getName());
        Object invoke = method.invoke(object, objects);
        return invoke;
    }
    public  void log (String msg){
        System.out.println("执行了"+msg+"方法");
    }
    }

package com.wyl.demo04;

import com.wyl.demo02.UserServlet;
import com.wyl.demo02.UserServletImpl;
import com.wyl.demo03.Rent;

public class Client {
    public static void main(String[] args) {
        //真实角色
        UserServletImpl userServlet = new UserServletImpl();
        //代理角色
        ProxyInvocationHandler prh = new ProxyInvocationHandler();
        //设置要代理的对象
        prh.setObject(userServlet);
        //代理类
        UserServlet proxy = (UserServlet) prh.getProxy();
        proxy.delete();


    }
}