肖恩画家:Observer模式

来源:百度文库 编辑:九乡新闻网 时间:2024/04/27 14:14:13
开会人(观察者)public class Person implements Observer{
  String name;
     int changeTimes=0;//记录本人看到的记录更改次数  
     /**
      * 
      */
     public Person(String name) {
         this.name = name;
     }    /*
      * 本人看到了通知
      *
      * @see java.util.Observer#update(java.util.Observable, java.lang.Object)
      */
     public void update(Observable o, Object arg) {
         String first=
         name +"说: 我已经看到了通知," + arg;
         String other=name + "说: 我考!,都该了N次了,N>="+ changeTimes + arg;
         System.out.println(changeTimes==0?first:other);
         changeTimes++;  
       }}通知开会人(被观察者)public class NoticeOfficer extends Observable { /**
     * 
     */
    public NoticeOfficer(String content) {       
     this.content = content;
    }    //重要通知
    String content; 
    void sendNotice(List p) {
      for(int i=0;i       Observer  o = (Observer)p.get(i);
       addObserver((Observer) o);
       }
        setChanged();
        notifyObservers(content);
    }  
} 测试类:public class Test{
    public static void main(String[] args) {
        NoticeOfficer officer = new NoticeOfficer("今天下午2:60 有会!");
        List personList = new ArrayList();
        personList.add(new Person("校长"));
        personList.add(new Person("流氓"));
        officer.sendNotice(personList);
        officer.content="会议改为3:50";
        officer.sendNotice(personList);
        officer.content="会议改为5:50";
        officer.sendNotice(personList);
    }
}