设计模式之观察者模式 Observer

public class Client {

public static void main(String[] args) {
//创建目标对象Observer
ConcreteSubject subject = new ConcreteSubject();

//创建观察者
ObserverA obs1 = new ObserverA();
ObserverA obs2 = new ObserverA();
ObserverA obs3 = new ObserverA();

//将观察者添加到目标对象subject的容器中
subject.addObserver(obs1);
subject.addObserver(obs2);
subject.addObserver(obs3);

//改变subject对象的状态
subject.set(5000);

//查看观察者的状态是否变化
System.out.println(obs1.getMyState());
System.out.println(obs2.getMyState());
System.out.println(obs3.getMyState());
}
}