代理模式--动态代理

动态代理只能代理接口，核心就是在运行时动态创建一个目标对象的代理对象，并允许程序在访问或是修改目标对象前根据业务需要进行控制。

package com.jerry.design.proxy;

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


	// 测试类
public class Test2 {

	public static void main(String[] args) {
		Order2 o = new Order2("book",12.00,1,"yushh");
	   System.out.println(o.toString());
	   DynamicProxy dp = new DynamicProxy();
	   Order o2 = dp.getProxyInstance(o);
	   o2.setName("book2","yushh2");
	   System.out.println(o.toString());
	    
	}
}

interface Order {
	public void setName(String name,String operator) ;
}
class Order2 implements Order{
	private String name;
	private double totle;
	private int num;
	private String operator;
	public String getName() {
		return name;
	}
	public void setName(String name,String operator) {
		this.name = name;
	}
	public double getTotle() {
		return totle;
	}
	public void setTotle(double totle) {
		this.totle = totle;
	}
	public int getNum() {
		return num;
	}
	public void setNum(int num) {
		this.num = num;
	}
	public String getOperator() {
		return operator;
	}
	public void setOperator(String operator) {
		this.operator = operator;
	}
	public Order2(String name, double totle, int num, String operator) {
		super();
		this.name = name;
		this.totle = totle;
		this.num = num;
		this.operator = operator;
	}
	@Override
	public String toString() {
		return "Order [name=" + name + ", totle=" + totle + ", num=" + num
				+ ", operator=" + operator + "]";
	}
	
}

class DynamicProxy implements InvocationHandler{
	
	private Order2 order = null;
	
	public Order getProxyInstance(Order2 order){
		this.order = order;
		Order order2   = (Order) Proxy.newProxyInstance(order.getClass().getClassLoader(),
				order.getClass().getInterfaces(), this);
		return order2;
	}

	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		if(method.getName().startsWith("setName")){
			if(order.getOperator()!=null&&order.getOperator().equals(args[1])){
				return method.invoke(order, args);
			}else{
				System.out.println("没有更改权限！！");
			}
		}else{
			method.invoke(order, args);
		}
		return null;
	}

	
	
}