publish - Subscribe

package subpub.interface_;
public interface Observer {
    public void update(Subscribe sub);
    public boolean isInterested();
}

package subpub.interface_;

import java.util.ArrayList;
import java.util.List;
public interface Subscribe {
    List observers = new ArrayList<>();
    public void append(Observer observer);
    public void remove(Observer observer);
    public void myNotify();
}

package subpub.interface_;
public class Anchor implements Subscribe{
   private String anName;

    public boolean isOnline() {
        return online;
    }

    public void setOnline() {
        this.online = true;
        myNotify();
    }

    private boolean online;
    public Anchor(String anName,boolean online) {
        this.anName = anName;
        this.online = online;
    }

    public String getAnName() {
        return anName;
    }

    public void setAnName(String anName) {
        this.anName = anName;
    }
    @Override
    public void append(Observer observer){
        observers.add(observer);
    }
    @Override
    public void remove(Observer observer){
        observers.remove(observer);
    }
    @Override
    public void myNotify() {
        for (Observer observer:observers) {
            if(observer.isInterested()){
                observer.update(this);
            }
        }
    }
}

package subpub.interface_;

/**
 * Created by liqiushi on 2017/11/22.
 */
public class Audience implements Observer {
    private String auName;
    Subscribe sub ;
    private boolean interested;
    public void setInterested(boolean interested) {
        this.interested = interested;
    }


    public Audience(String auName,Subscribe sub) {
        this.auName = auName;
        this.sub =sub;
        sub.append(this);
    }

    @Override
    public void update(Subscribe sub) {
        System.out.println("   " + this.auName + ":" + ((Anchor) sub).getAnName() + "     ！");
    }

    @Override
    public boolean isInterested() {
        return interested;
    }
}

package subpub;

import subpub.interface_.Anchor;
import subpub.interface_.Audience;
import subpub.interface_.Observer;
import subpub.interface_.Subscribe;
public class TestMain {
    public static void main(String[] args) {
          Subscribe subscribe = new Anchor("   ",false);
        Observer childAu = new Audience("   ",subscribe);
        Observer womanAu = new Audience("   ",subscribe);
        ((Audience)childAu).setInterested(true);
        ((Anchor)subscribe).setOnline();
      
    }
}
//      :        ！