题目：一个男孩让另一个男孩代理去送一个女孩礼物

public class SchoolGirl {    private String name;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

 

public interface GiveGift {    void giveDoll();    void giveFlower();    void giveChocolate();}

 

public class Pursuit implements GiveGift {    SchoolGirl mm;    public Pursuit(SchoolGirl mm) {        this.mm = mm;    }    @Override    public void giveDoll() {        System.out.println(mm.getName() + "送你洋娃娃");    }    @Override    public void giveFlower() {        System.out.println(mm.getName() + "送你鲜花");    }    @Override    public void giveChocolate() {        System.out.println(mm.getName() + "送你巧克力");    }}

 

public class Proxy implements GiveGift {    Pursuit gg;    public Proxy(SchoolGirl mm) {        gg = new Pursuit(mm);    }    @Override    public void giveDoll() {        gg.giveDoll();    }    @Override    public void giveFlower() {        gg.giveFlower();    }    @Override    public void giveChocolate() {        gg.giveChocolate();    }}

public class Action {    public static void main(String args[]) {        SchoolGirl jiaojiao = new SchoolGirl();        jiaojiao.setName("李娇娇");        Proxy daili = new Proxy(jiaojiao);        daili.giveDoll();        daili.giveFlower();        daili.giveChocolate();    }}

 

打印结果：

李娇娇送你洋娃娃李娇娇送你鲜花李娇娇送你巧克力

 

原理就是：

1.Pursuit和Proxy都实现了GiveGift接口，但Proxy中实际调用的也是Pursuit的方法

2.Proxy的构造函数也是为了生成Pursuit的对象

3.所以在Action中，我们只看到了Proxy在忙来忙去，Pursuit被隐藏了起来