观察者模式_简单例子.docVIP

实验五、观测者模式（4学时） 【】【】【】public class ConcreteObserver implements Observer { private Subject mConcreteSubject; public ConcreteObserver(Subject mConcreteSubject){ this.mConcreteSubject = mConcreteSubject ; } public void update () { System.out.println(得到信息:+mConcreteSubject.getInformation()); } } 主题 public interface Subject { public void attach (Observer o); public void detach (Observer o); public String getInformation(); public void notifyObservers (); public String setInformation(String s); } 具体主题 import java.util.ArrayList; public class ConcreteSubject implements Subject { public ArrayListObserver mObserver; private String Information=; private Object mState; public ConcreteSubject(){ mObserver=new ArrayListObserver(); } public Object getState () { return mState; } public void setState (Object val) { mState=val; } public void attach (Observer o) { if(o!=null) mObserver.add(o); } public void detach (Observer o) { if(mObserver.contains(o)) mObserver.remove(o); } public String setInformation(String s){ Information=s; return s; } public String getInformation(){ return Information; } public void notifyObservers () { for(int i=0;imObserver.size();i++){ Observer o= mObserver.get(i); o.update(); } } } 客户端 public class Application { public static void main(String[] args) { Subject s=new ConcreteSubject(); Observer o1=new ConcreteObserver(s); Observer o2=new ConcreteObserver(s); s.attach(o2); s.attach(o1); s.setInformation(你好); s.notifyObservers(); } } 2、请用观测者模式实现一个汽车驾驶室仪表系统，当汽车改变速度、改变方向时实时显示汽车的速度、方向、指示灯等信息。 观察者速度表 package driver; import java.util.Observable; import java.util.Observer; import java.awt.*; import java.awt.event.*; import javax.