Name: joT67522 Date: 11/11/97


The problem is very hard to reproduce, I tried
with a small testcase but unfortunately the test
case runs perfect.
-) I have a class (Main) with a static instance of
   the application window. The member can only
   be set in one method. (initFrame)
-) The method is called in only 2 situations in
   my application. Either from main or from a
   settings view.
-) With JDK 1.1.4 when calling the method for the
   2nd time (the member is already set and never
   reset) it suddenly is null.
-) When I switch back to JDK 1.1.3 the code works
   correct without recompiling it. So I assume it
   is a problem of the virtual machine.

Sample code (however this small sample works
correct; just my complex APP has problems - but I
was not able to reproduce it in a small sample).
I could send you the full application; but where
shall I send it to ???

class Main
{
  private static MyMainWindow myFrame=null;

  /**
   * only method to access myFrame !!!
   */
  public static initFrame()
  {
    if ( myFrame==null )
    {
System.out.println( "not set ... initialising" );
      myFrame=new MyMainWindow();
      myFrame.show();
    }
    else
    {
System.out.println( "set ... initialising" );
      myFrame.restore()
    }
  }

  /**
   * tests if the settings are correct, if yes it
   * directly opens the main window with initFrame
   * if no it first opens the settings view which
   * internally calls initFrame.
   */
  public static void main(String argv[])
  {
    "if ( settings ok )
    {
      initFrame();
    }
    else
    {
      openSettings(); // here myFrame is still null
    }
  }
}

class Settings extends Frame
{
  // class logic is not important. In the class
  // there is the following method
  private void okButtonPressed()
  {
    // opens the frame window if not already open.
    Main.initFrame();
  }
}

Ok, above is the only code in my app. accessing
the static variable. I made the following
investigations:

1) if I have bad settings everything is fine
   The frame is not initialized by main but
   by Settings:
   initFrame reports that the frame is null and
   creates a new frame window.

2) if the setting are correct then
  2a) initFrame is called from the main method
      reports that myFrame is null and creates
      the main window. (The window remains open)
  2b) Now from the main window the settings are
      opened - the user presses ok and so
      initFrame is called again.

  Now initFrame reports that myFrame is NOT SET !!
  with Java 1.1.4. !!! and it opens another
  instance of MyMainWindow.

  2c) When I do 2b) again now initFrame reports
      that myFrame is set.

  With Java 1.1.3 2b) works as expected (initFrame
  says that myFrame is set and restores it).

Hope my report is not too vague and you are
taking it seriously. I still try to get a small
testcase ... If I have you'll get it.

Chris
(Review ID: 19170)
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