//actionlistener可以作為外部類、內(nèi)部類、匿名類進行監(jiān)聽，本示例使用內(nèi)部類
//兩個監(jiān)聽者對應(yīng)兩個button組件
private class bt1Handler implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        jTextArea.setText("按鈕一點擊");
    }
}
private class bt2Handler implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        jTextArea.setText("按鈕二點擊");
    }
}
//添加監(jiān)視器
bt1.addActionListener(bt1Handler);
bt2.addActionListener(bt2Handler);

//示例：我與朋友打電話讓他去我家吃飯，朋友同意
//Me類：
public class Me implements callable {
MyFriend friend;
public Me( MyFriend friend){
this.friend=friend;
}
public void callFriend() throws Exception {
	System.out.println("開始執(zhí)行同步回調(diào)函數(shù)");
System.out.println("去我家吃飯");
friend.answer(this);
System.out.println("開始執(zhí)行同步回調(diào)函數(shù)");
}
@Override
//回調(diào)函數(shù)
public void call(){
System.out.println("好好好");
}
}
//MyFriend類：
public class MyFriend {
public void answer( callable callable) throws Exception{
System.out.println("接線中.....");
callable.call();
}
}
//callable接口：
public interface callable {
public void call();
}
//test類：
public class testCallBack {
public static void main(String[] args) throws  Exception{
MyFriend friend=new MyFriend();
Me me=new Me(friend);
me.callFriend();
}
}

//與同步回調(diào)區(qū)別是，回調(diào)函數(shù)單開一個線程，不影響和Me類等待回調(diào)函數(shù)執(zhí)行完成
public void callFriend() throws Exception {
System.out.println("開始執(zhí)行異步回調(diào)函數(shù)");
new Thread(new Runnable() {
  @Override
  public void run() {
      try {
          System.out.println("去我家吃飯");
          friend.answer(Me.this);
      } catch (Exception e) {
          e.printStackTrace();
      }
  }
}).start();
System.out.println("異步回調(diào)函數(shù)執(zhí)行完成");
}

//你關(guān)注的up主更新了，并私信通知他的所有粉絲

//觀察者接口
public interface Observer {
    public void update(String video);
}
//具體觀察者（粉絲）類
public class Fan implements Observer{
    private String name;//粉絲姓名
    public Fan(String name){
        this.name=name;
    }

    @Override
    public void update(String video){
        System.out.println(name+"! "+video);
    }
}

//被觀察者接口
public interface UpLoader {
    //添加粉絲
    void addFan(Fan fan);
    //刪除粉絲
    void deleteFan(Fan fan);
    //通知粉絲
    void informFan(String video);
}

//實現(xiàn)類
public class BilibliUpLoader implements UpLoader{
    public String getName() {
        return name;
    }

    private String name;
    private List<Fan> fanList=new ArrayList<>();
    public BilibliUpLoader(String name){
        this.name=name;
    }
    @Override
    public void addFan(Fan fan) {
        fanList.add(fan);
    }

    @Override
    public void deleteFan(Fan fan) {
        fanList.remove(fan);
    }

    @Override
    public void informFan(String video) {
        for(Fan fan:fanList){
            fan.update(video);
        }
    }
}
//測試類
public class test {
    public static void main(String[] args) {
        BilibliUpLoader bilibliUpLoader=new BilibliUpLoader("Mike");
        Fan fan=new Fan("jack");
        Fan fan1=new Fan("Bob");
        Fan fan2=new Fan("Mary");
        Fan fan3=new Fan("Lisa");
        bilibliUpLoader.addFan(fan);
        bilibliUpLoader.addFan(fan1);
        bilibliUpLoader.addFan(fan2);
        bilibliUpLoader.addFan(fan3);
        bilibliUpLoader.informFan(bilibliUpLoader.getName()+"的新視頻來了");
    }
}