Java/J2ME/Exception

Test Exception

/*--------------------------------------------------
* TestException.java
*
* Example from the book:     Core J2ME Technology
* Copyright John W. Muchow   http://www.CoreJ2ME.ru
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class TestException extends MIDlet implements CommandListener
{
  private Display display;              // Reference to Display object for this MIDlet
  private Form fmMain;                 // A Form 
  private Command cmExit;              // A Command to exit the MIDlet
  private boolean safeToExit = false;   // Is it safe to exit the MIDlet?
  // MIDlet constructor
  public TestException()
  {
    display = Display.getDisplay(this);
    
    cmExit = new Command("Exit", Command.SCREEN, 1);
    fmMain = new Form("Test Exception");
    fmMain.addCommand(cmExit);
    fmMain.setCommandListener(this);
  }
  // Called by application manager to start the MIDlet.
  public void startApp()
  {
    display.setCurrent(fmMain);
  }
  // We are about to be placed in the Paused state
  public void pauseApp()
  {
  }
  // We are about to enter the Destroyed state
  public void destroyApp(boolean unconditional) throws MIDletStateChangeException
  {
    System.out.println("Inside destroyApp()");
    // If we do not need to unconditionally exit
    if (unconditional == false)
    {
      System.out.println("Requesting not to be shutdown");
      throw new MIDletStateChangeException("Please don"t shut me down.");
    }      
  }
  // Check to see if the Exit command was selected
  public void commandAction(Command c, Displayable s)
  {
    if (c == cmExit)
    {
      try
      {
        // Is it ok to exit?
        if (safeToExit == false)
          destroyApp(false);
        else
        {
          destroyApp(true);
          notifyDestroyed();
        }
      }
      catch (MIDletStateChangeException excep)
      {
        safeToExit = true;   // Next time, let"s exit
        System.out.println(excep.getMessage());
        System.out.println("Resuming the Active state");
      }
    }
  }
}