1  import java.awt.*;

  2  import java.awt.event.*;

  3  import java.time.*;

  4  import javax.swing.*;

  5  import javax.swing.Timer;

  6  

  7  /**

  8     This program shows a clock that is updated once per second.

  9  */

 10  public class TimerTester

 11  {

 12     public static void main(String[] args)

 13     {

 14        JFrame frame = new JFrame();

 15  

 16        final int FIELD_WIDTH = 20;

 17        JTextField textField = new JTextField(FIELD_WIDTH);

 18  

 19        frame.setLayout(new FlowLayout());

 20        frame.add(textField);

 21  

 22        ActionListener listener

 23           = event -> textField.setText(Instant.now().toString());

 24        final int DELAY = 1000;

 25           // Milliseconds between timer ticks

 26        Timer t = new Timer(DELAY, listener);

 27        t.start();

 28  

 29        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

 30        frame.pack();

 31        frame.setVisible(true);

 32     }

 33  }