计时器延迟不起作用？

Question

I am trying to make this program print the current time in the console every second.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.Timer;
import java.util.Date;

public class E10U27 extends JFrame {
    public static void main(String[] args){

   // Prep the listener to respond
   class TimerListener implements ActionListener {
      public void actionPerformed(ActionEvent event) {

         Date now = new Date();
         System.out.println(now);
      }
   }

   ActionListener listener = new TimerListener();
   final int DELAY = 1000; 
   Timer t = new Timer(DELAY, listener);
   t.start();    
}
}

However, it prints like 50 of just a single time (ex. 2:52 50 times), and so on. It does tick correctly though. How to make it run correctly? Are there any mistakes in my code?

Answer 1

I ran the code without errors, but it finished without showing the date in the interval assigned to Timer, so I made some changes

1. Change the DELAY to 1000 (1 second) to print the current time every second

final int DELAY = 1000;

2. Create the frame to make the program keep running, otherwise the main method will finish (new E10U27()).setVisible(true);

This is the program with the modifications, it prints the current time every second:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.Timer;
import java.util.Date;

public class E10U27 extends JFrame {
    public static void main(String[] args){

        // Prep the listener to respond
        class TimerListener implements ActionListener {
            public void actionPerformed(ActionEvent event) {

                Date now = new Date();
                System.out.println(now);
            }
        }

        ActionListener listener = new TimerListener();
        final int DELAY = 1000; // Milliseconds between timer ticks
        Timer t = new Timer(DELAY, listener);
        t.start();

        (new E10U27()).setVisible(true);
    }
}

Answer 2

final int DELAY = 999999;    
Timer timer = new Timer(DELAY, new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
    //Your Action    
    }
    });
    timer.start();

Refer the document here Java Docs