Displaying a Simple Timer

Question

i want to display a simple MM:SS count-up timer on screen.
im using:
int time = (int)(curr - start);
Date date = new Date();
date.setMinutes(time / 60)
date.setSeconds(time % 60)
gfx.drawString <- simpleDateFormat.(formatdate) // formatted with "mm:ss"i see those methods as deprecated and i know how to set the equivalent
values in Calendar put i dont see a Calendar formatter.
this would be much simpler if i could skip Date altogether and just use a 1.5 formatter
but this needs to be 1.4.2 friendly.
Any suggestions?

Answer 1

You could also use a DecimalFormat with Calendar#get (...)
This code uses bothe ways ;-)import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class CountUpTimer implements ActionListener {
   Calendar calendar = Calendar.getInstance ();
   JFrame frame = new JFrame ("Count up timer");
   JLabel labelCalendar = new JLabel ("00:00");
   JLabel labelDate = new JLabel ("00:00");
   JButton button = new JButton ("Start");
   Timer timer = new Timer (1000, this);
   DecimalFormat dec = new DecimalFormat ("00");
   SimpleDateFormat dtf = new SimpleDateFormat ("mm:ss");
   public CountUpTimer () {
   void makeUI () {
      button.addActionListener (new ActionListener () {
         public void actionPerformed (ActionEvent e) {
            if (timer.isRunning ()) {
               timer.stop ();
               button.setText ("Start");
            } else {
               calendar.set (Calendar.MINUTE, 0);
               calendar.set (Calendar.SECOND, 0);
               timer.start ();
               button.setText ("Stop");
      frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
      frame.setSize (200, 150);
      frame.setLayout (new GridLayout (0, 1));
      frame.add (labelCalendar);
      frame.add (labelDate);
      frame.add (button);
      frame.setLocationRelativeTo (null);
      frame.setVisible (true);
   public void actionPerformed (ActionEvent e) {
      calendar.set (Calendar.SECOND,
            calendar.get (Calendar.SECOND) + 1);
      labelCalendar.setText (dec.format (calendar.get (Calendar.MINUTE)) + ":"
            + dec.format (calendar.get (Calendar.SECOND)));
      labelDate.setText (dtf.format (calendar.getTime ()));
   public static void main (String[] args) {
      SwingUtilities.invokeLater (new Runnable () {
         public void run () {
            new CountUpTimer ().makeUI ();
}db