Status Display

Question

I have written an application which runs in a JFrame. I want to display the message "Processing...." on a JLabel while my program is performing its calculations. Although I use the setText() method of JLabel just before the processing starts, the label stays blank until the processing is actually over so all the user can see is "Processing complete". Even a repaint() immediately after the call to setText() doesn't help. Similarly, the status doesn't change to "Processing...." once the next input is entered. What could be the problem?

Answer 1

adamflater is almost right. Only problem is you need to update GUI components in the Swing Event thread, which means you need to use something like SwingUtilities.invokeLater() instead of a simple Thread.
I'd do something more like....
public class Cross extends JFrame implements ActionListener
private JLabel statusLabel;
// main, GUI setup and other methods...
public void actionPerformed(...)
     Thread procThread = new Thread()
          public void run()
               updateStatus("Processing....");
               //...processing code...
               updateStatus("Processing Complete" );
     procThread.start();
private void updateStatus(String sText)
     SwingUtilities.invokeLater(new Runnable()
       public void run()
          statusLabel.setText(sText);
}