package Bean; import java.util.ArrayList; import java.util.Iterator; import Interface.Observer; import Interface.Quackable; /** * Created by Administrator on 2017/7/14. */ public class Flock implements Quackable //组合模式 { ArrayList quackers = new ArrayList<>(); Observable observable; public Flock() { observable = new Observable(this); } public void add(Quackable quackable) { quackers.add(quackable); } @Override public void quack() { System.out.println(quackers.size()); Iterator iterator = quackers.iterator(); while (iterator.hasNext()) { Quackable quackable= iterator.next(); quackable.quack(); } } public void registerObserver(Observer observer) { Iterator iterator = quackers.iterator(); while (iterator.hasNext()) { Quackable quackable= iterator.next(); quackable.registerObserver(observer); } } @Override public void notifyObservers() { observable.notifyObservers(); } }