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package xyz.pattern.observer.subpackage2;

public interface Obsever {
	public void toUpdate();
}

package xyz.pattern.observer.subpackage2;

public class ConcreteObseverA  implements Obsever{
	private Subject s;
	public ConcreteObseverA(Subject s){
		this.s=s;
	}
//	订阅
	public void attachToSubject() {
		if (s!=null) {
			s.addObsever(this);
		}
	}
//	取消订阅
	public void detachToSubject() {
		if (s!=null) {
			s.removeObsever(this);
		}
	}
	@Override
	public void toUpdate() {
		int state = s.getState();
		switch (state) {
		case 0:
			actionA(state);
			break;
		case 1:
			actionB(state);
			break;
		default:
			defaultAction(state);
			break;
		}
	}
	private void actionA(int state) {
		System.out.println("状态"+state+":"+this.getClass().getSimpleName()+"采取行动A");
	}
	private void actionB(int state) {
		System.out.println("状态"+state+":"+this.getClass().getSimpleName()+"采取行动A");
	}
	private void defaultAction(int state) {
		System.out.println("状态"+state+":"+this.getClass().getSimpleName()+"采取行动A");
	}
}

package xyz.pattern.observer.subpackage2;

public class ConcreteObseverB implements Obsever{
		private Subject s;
		public ConcreteObseverB(Subject s){
			this.s=s;
		}
//		订阅
		public void attachToSubject() {
			if (s!=null) {
				s.addObsever(this);
			}
		}
//		取消订阅
		public void detachToSubject() {
			if (s!=null) {
				s.removeObsever(this);
			}
		}
		@Override
		public void toUpdate() {
			int state = s.getState();
			switch (state) {
			case 0:
				actionA(state);
				break;
			case 1:
				actionB(state);
				break;
			default:
				defaultAction(state);
				break;
			}
		}
		private void actionA(int state) {
			System.out.println("状态"+state+":"+this.getClass().getSimpleName()+"采取行动A");
		}
		private void actionB(int state) {
			System.out.println("状态"+state+":"+this.getClass().getSimpleName()+"采取行动A");
		}
		private void defaultAction(int state) {
			System.out.println("状态"+state+":"+this.getClass().getSimpleName()+"采取行动A");
		}

	}

package xyz.pattern.observer.subpackage2;

import java.util.AbstractList;
import java.util.ArrayList;

public class Subject {
	private AbstractList obsevers=new ArrayList<>();
	private int state;
	
	public int getState() {
		return state;
	}
	public void setState(int state) {
		this.state=state;
		notofyAllObsevers();
	}
	private void notofyAllObsevers() {
		for(Obsever o:obsevers) {
			o.toUpdate();
		}
	}
	public void addObsever(Obsever o) {
		obsevers.add(o);
	}
	public void removeObsever(Obsever o) {
		obsevers.remove(o);
	}
}

package xyz.pattern.observer.subpackage2;

public class Client {
	public static void main(String[] args) {
		Subject s = new Subject();
		ConcreteObseverA obseverA = new ConcreteObseverA(s);
		obseverA.attachToSubject();
		ConcreteObseverB obseverB = new ConcreteObseverB(s);
		obseverB.attachToSubject();
		s.setState(0);
		s.setState(1);
		s.setState(-1);
	}
}