观察者设计模式 （observer模式） java实现

package Observer.MyTest;import java.util.Observable;import    java.util.Observer; public class ObserverTest {/** * @param args */public static void main(String[] args) {observered oe=new observered();observerB ob=new observerB();oe.addObserver(new observerA());oe.addObserver(ob);oe.showb();//oe.showg();}//被观察者static class observered extends  Observable{//场上表现public void showg(){System.out.println("选手变现得不错");setChanged();notifyObservers(1);}public void showb(){System.out.println("选手变现得一般");setChanged();notifyObservers(2);}}//观察者--竞争对手static class observerA implements Observer{@Overridepublic void update(Observable o, Object arg) {Integer i=(Integer) arg;System.out.print("竞争对手");if(i.intValue()==1){System.out.println("有压力");}else{System.out.println("有希望进入下一轮");}}}//观察者--观众static class observerB implements Observer{@Overridepublic void update(Observable o, Object arg) {Integer i=(Integer) arg;System.out.print("观众");if(i.intValue()==1){System.out.println("鼓掌");}else{System.out.println("唏嘘");}}}}