为什么编译器告诉我“actionPerformed 方法未实现”？

Question

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;

import javafx.event.ActionEvent;

public class hello {
  public static void main(String[] args) {
    TalkClock clock = new TalkClock();
    clock.start(1000, true);
    System.out.println("xxxx");
    JOptionPane.showMessageDialog(null, "Quit program?");
    System.exit(0);

  }
}

class TalkClock
{
  public void start(int interval, boolean beep){
    ActionListener listener = new ActionListener() 
      {

        public void actionPerformed(ActionEvent event) {
          System.out.println("At the tone, the time is " + new Date());
          if (beep) Toolkit.getDefaultToolkit().beep();
        }
      };
    Timer t = new Timer(interval, listener);
    t.start();
  }
}

I run it in my Mac. The error is

hello.java:24: error: <anonymous TalkClock$1> is not abstract and does not override abstract method actionPerformed(ActionEvent) in ActionListener
      {
      ^
1 error

Answer 1

You import the ActionEvent from JavaFX. You need to import the swing class.