定时器延迟不起作用?

Timer Delay Not Working?

我试图让这个程序每秒在控制台打印当前时间。

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();    
}
}

但是,它只打印一次 50(例如 2:52 50 次),依此类推。它确实正确地勾选了。如何正确地运行?我的代码有错误吗?

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

在此处参考文档Java Docs

我运行代码没有错误,但是它完成时没有显示分配给Timer的间隔中的日期,所以我做了一些修改

  1. 将DELAY改为1000(1秒),每秒打印一次当前时间

final int DELAY = 1000;

  1. 创建框架使程序保持运行,否则main方法将完成(new E10U27()).setVisible(true);

这是经过修改的程序,它每秒打印一次当前时间:

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);
    }
}