Need help with Process execution time display

Hi All,

I am new to Java and I am facing problem in displaying the process execution time concurrently while execution is taking place.

I want to diplay time in format mm:ss while the execution is taking place. For the same, i have written code snippet like this,

<----
String s;
long ref = System.currentTimeMillis();
javax.swing.Timer timer2;
SimpleDateFormat timef = new SimpleDateFormat("mm:ss");

timer = new javax.swing.Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent e) {
s = timef.format(new Date(System.currentTimeMillis() - ref));
Elapsed.setText("Elapsed Time = " + s);
}
});
timer.start();

---->

Although, I am able to see the Elapsed time, it is always starting from 30:00 . I want to know where I am making a mistake. Would appreciate if you can point it out to me.

Thanks!

You've got a bug somewhere else in your code.

We know this since if we user the code you've posted in a simple program, it works:

Code:

---

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.*;

public class TimeDisplay {
  static long ref = System.currentTimeMillis();

  private static void createAndShowGUI() {
    final SimpleDateFormat timef = new SimpleDateFormat("mm:ss");
    final JLabel elapsedLabel = new JLabel("Elapsed Time = " + timef.format(new Date(0)),
        SwingUtilities.CENTER);

    Timer timer = new javax.swing.Timer(1000, new ActionListener() {
          public void actionPerformed(ActionEvent e) {
            Date currentDate = new Date(System.currentTimeMillis() - ref);
            String formattedDate = timef.format(currentDate);
            elapsedLabel.setText("Elapsed Time = " + formattedDate);
          }
        });
    timer.start();

    JPanel panel = new JPanel(new BorderLayout());
    panel.setPreferredSize(new Dimension(400, 200));
    panel.add(elapsedLabel);

    JFrame frame = new JFrame("TimeDisplay");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(panel);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    });

  }
}

---

So logic tells us that your error is somewhere else in code that you haven't posted. So you'll need to do a little debugging here to try to isolate the offending code.

Much luck.

I executed your program... Still getting the same problem!

Its always starting from 30:00 (like 30:00, 30:01,30:02 and so on...). Has it got something to do with system time?

By the way, attaching screen shot of output of the above program..... I know, I might be stretching people here but I can't seem to get it right...Nevertheless, appreciate your help!

On further reflection, I think that I was wrong above. You and I probably shouldn't use Date to represent elapsed time as Date represents a point in time, not elapsed time (see this for more detail).

Perhaps just getting the system time and doing the math yourself would work better:

Code:

---

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class TimeDisplay {
  static long ref = System.currentTimeMillis();
  static String formatString = "%02d:%02d";

  private static void createAndShowGUI() {
    final JLabel elapsedLabel = new JLabel("Elapsed Time = " + String.format(formatString, 0, 0),
        SwingUtilities.CENTER);

    Timer timer = new javax.swing.Timer(1000, new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        long currentDate = System.currentTimeMillis();
        long elapsedSeconds = (currentDate - ref)/1000;
        int minutes = (int) (elapsedSeconds / 60);
        int seconds = (int)(elapsedSeconds % 60);
        String formattedTime = String.format(formatString, minutes, seconds);
        elapsedLabel.setText("Elapsed Time = " + formattedTime);
      }
    });
    timer.start();

    JPanel panel = new JPanel(new BorderLayout());
    panel.setPreferredSize(new Dimension(400, 200));
    panel.add(elapsedLabel);

    JFrame frame = new JFrame("TimeDisplay");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(panel);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    });

  }
}

---

Yeah, SimpleDateFormat is locale-sensitive, and murali18 must be in a time zone that has a half-hour offset. You can still use SimpleDateFormat, but you need to use UTC time zone.

Code:

---

        SimpleDateFormat timef = new SimpleDateFormat("mm:ss");
        timef.setTimeZone(TimeZone.getTimeZone("UTC"));

---

(I haven't tried it, but it should work.)

-Gary-

I have found the Java date/time/calendar libraries a bit confusing. I've heard good things about JodaTime and am thinking of checking it out.