Time refresh doesn't work .... probably flaws in the code. Please help ...

Question

Making a time display and try to keep track of the system time every second. When I pruposely changed the system time for the first time, it worked; another time it wouldn't work and it stopped. Where is the bug please ...
tick_24 = new Timer ( 1000, new ActionListener () {
     public void actionPerformed ( ActionEvent ae ) {
          times = (GregorianCalendar) Calendar.getInstance ();
          int h = times.get(Calendar.HOUR_OF_DAY);
          int m = times.get(Calendar.MINUTE);
          int s = times.get(Calendar.SECOND);
          String time_now = configTime(h,m,s);
                // time_display is a JLabel;
          time_display.setText(time_now);
          times.add(Calendar.SECOND,1);
tick_24.start();

Answer 1

Can't help with the bug, but try this, you might get something out of it
import java.util.*;
import java.text.*;
import javax.swing.*;
import java.awt.*;
class TimeDisplay extends JFrame
  private static JLabel lbl = new JLabel();
  public static void main(String args[])
    new TimeDisplay();
  public TimeDisplay()
    super("Time Display");
    setSize(200,50);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    Container frame = getContentPane();
    JPanel jp = new JPanel(new FlowLayout());
    jp.add(lbl);
    frame.add(jp);
    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    setLocation((dim.width - frame.getWidth())/2, (dim.height - frame.getHeight())/2);
    setContentPane(frame);
    setVisible(true);
    startTheClock();
  private static void startTheClock()
    final java.util.Timer tmr = new java.util.Timer();
    tmr.scheduleAtFixedRate(new TimerTask()
      SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
      int ctr;
      public void run()
        Calendar cal = Calendar.getInstance();
        lbl.setText(sdf.format(cal.getTime()));
        ctr++;
        if(ctr==20) tmr.cancel();
    },0,1000);
}