博客

观察者模式

#1.定义接口`

public interface Person {
    void getMessages(String s);
}

#2.接口需要实现
//两个观察者类和一个被观察者类

public class LaoLi  implements Person{
    private String name = "小李";
    public LaoLi(){}
    @Override
    public void getMessages(String s) {
        System.out.println(name+"接到小美打的电话，电话内容是：->"+s);
    }
}

public class LaoWang implements Person {
    private String  name = "小王";
    public LaoWang(){}
    @Override
    public void getMessages(String s) {
        System.out.println(name+"接到小美打过来的电话，电话内容是："+s);
    }
}


//被观察者类
```java
public class XiaoMei {
    private List<Person> list = new ArrayList<Person>();
    public XiaoMei(){}
    public void addPerson(Person person){
        list.add(person);
    }
    public void notifyPerson(){
        for (Person person : list) {
            person.getMessages("你们过来吧，谁先过来谁就能陪我一起玩儿游戏!");
        }
    }
}

#3.测试类

public class Test {
    public static void main(String[] args) {
        XiaoMei xiaoMei = new XiaoMei();
        LaoWang laoWang = new LaoWang();
        LaoLi laoLi = new LaoLi();
        xiaoMei.addPerson(laoWang);
        xiaoMei.addPerson(laoLi);
        xiaoMei.notifyPerson();
    }
}

结果：
小王接到小美打过来的电话，电话内容是：你们过来吧，谁先过来谁就能陪我一起玩儿游戏!
小李接到小美打的电话，电话内容是：->你们过来吧，谁先过来谁就能陪我一起玩儿游戏!