java基本事件处理机制解析

//actionlistener可以作为外部类、内部类、匿名类进行监听，本示例使用内部类
//两个监听者对应两个button组件
private class bt1Handler implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        jTextArea.setText("按钮一点击");
    }
}
private class bt2Handler implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        jTextArea.setText("按钮二点击");
    }
}
//添加监视器
bt1.addActionListener(bt1Handler);
bt2.addActionListener(bt2Handler);

//示例：我与朋友打电话让他去我家吃饭，朋友同意
//Me类：
public class Me implements callable {
MyFriend friend;
public Me( MyFriend friend){
this.friend=friend;
}
public void callFriend() throws Exception {
	System.out.println("开始执行同步回调函数");
System.out.println("去我家吃饭");
friend.answer(this);
System.out.println("开始执行同步回调函数");
}
@Override
//回调函数
public void call(){
System.out.println("好好好");
}
}
//MyFriend类：
public class MyFriend {
public void answer( callable callable) throws Exception{
System.out.println("接线中.....");
callable.call();
}
}
//callable接口：
public interface callable {
public void call();
}
//test类：
public class testCallBack {
public static void main(String[] args) throws  Exception{
MyFriend friend=new MyFriend();
Me me=new Me(friend);
me.callFriend();
}
}

//与同步回调区别是，回调函数单开一个线程，不影响和Me类等待回调函数执行完成
public void callFriend() throws Exception {
System.out.println("开始执行异步回调函数");
new Thread(new Runnable() {
  @Override
  public void run() {
      try {
          System.out.println("去我家吃饭");
          friend.answer(Me.this);
      } catch (Exception e) {
          e.printStackTrace();
      }
  }
}).start();
System.out.println("异步回调函数执行完成");
}

//你关注的up主更新了，并私信通知他的所有粉丝

//观察者接口
public interface Observer {
    public void update(String video);
}
//具体观察者（粉丝）类
public class Fan implements Observer{
    private String name;//粉丝姓名
    public Fan(String name){
        this.name=name;
    }

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

//被观察者接口
public interface UpLoader {
    //添加粉丝
    void addFan(Fan fan);
    //删除粉丝
    void deleteFan(Fan fan);
    //通知粉丝
    void informFan(String video);
}

//实现类
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);
        }
    }
}
//测试类
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()+"的新视频来了");
    }
}