java设计模式之观察者模式

/**
* 被监视的需要实现这个接口，用于添加，删除，通知观察者
* @author zhou
*
*/
public interface Subject {
public void addObser(Obsered obsered);
public void deletObser(Obsered obsered);
public void notifiObser(String context);

}

/**
* 观察者实现这个接口，接收消息
* @author zhou
*
*/
public interface Observer {
public void ubdate(String str);
}

//被观察者
public class ConcreteSubject  implements Preson,Subject{
public List<Observer> list = new ArrayList<Observer>();

@Override
public void addObser(Observer obsered) {
// TODO Auto-generated method stub
list.add(obsered);//添加观察者

}

@Override
public void deletObser(Observer obsered) {
// TODO Auto-generated method stub
list.remove(obsered);//移除观察者
}

@Override
public void notifiObser(String str) {
// TODO Auto-generated method stub
for(Observer obsered:list){
obsered.ubdate(str);//通知观察者消息
}

}

@Override
public void eat() {
// TODO Auto-generated method stub
this.notifiObser("这货在吃饭");

}

@Override
public void haveFun() {
// TODO Auto-generated method stub
this.notifiObser("这货在玩耍");
}

}

/**
* 观察者
* @author zhou
*
*/
public class ConcreteObserver implements Observer {

@Override
public void ubdate(String str) {
// TODO Auto-generated method stub
System.out.println("韩非子在吃饭");
//在这里我已经得到消息
happy();
}

public void happy() {
// TODO Auto-generated method stub
System.out.println("这货很快乐");
}

}

ConcreteSubject concreteSubject = new ConcreteSubject();
Observer lisi = new ConcreteObserver();

concreteSubject.addObser(liusi);

concreteSubject.haveFun();