java设计模式--代理模式

Posted 2022-02-16 yimengyizhen

代理模式：为其他对象提供一种代理来控制对这个对象的访问。我们来看这样一个简单的例子，现在超市商家不直接把商品交给客户，而是通过一些平台的外卖小哥把商品送到客户手中，此时外卖小哥就起到了代理的作用。代码如下：

//客户类
public class Customer 

    public String name;

    public String getName() 
        return name;
    

    public void setName(String name) 
        this.name = name;
    


//出售商品的代理接口，这样就可以在所有实现这个接口的超市类中都可以使用外卖小哥类（Proxy代理）
public interface SaleGoods 
    void saleWater();
    void saleFood();
    void saleFruits();


//超市实现代理接口（定义外卖小哥所代表的真实的实体）
public class SuperMarket implements SaleGoods 

    Customer customer = null;

    public SuperMarket(Customer customer)
        this.customer = customer;
    
    @Override
    public void saleWater() 
        System.out.println(customer.getName() +"购买的水");
    

    @Override
    public void saleFood() 
        System.out.println(customer.getName() +"购买的食物");
    

    @Override
    public void saleFruits() 
        System.out.println(customer.getName() +"购买的水果");
    


//外卖小哥实现代理接口
public class TakeOutBrother implements SaleGoods 
    SuperMarket superMarket = null;

    public  TakeOutBrother(Customer customer)
　　　　//通过超市的引用调用超市的方法
        this.superMarket = new SuperMarket(customer);
    
    @Override
    public void saleWater() 
　　　　　//调用超市的方法
        superMarket.saleWater();
    

    @Override
    public void saleFood() 
        superMarket.saleFood();
    

    @Override
    public void saleFruits() 
        superMarket.saleFruits();
    


public class Test 
    public static void main(String[] args) 
        Customer customer = new Customer();
        customer.setName("zhangsan");
        TakeOutBrother takeOutBrother = new TakeOutBrother(customer);
        takeOutBrother.saleFood();
        takeOutBrother.saleFruits();
        takeOutBrother.saleWater();