Problem when using JFileChooser in JApplet

[Amit Rosner]

Hi!
I have a signed applet in which I want to use JFileChooser.
The problem is: whenever the execution gets to the line: "JFileChooser chooser = new JFileChooser()"
I get a modal dialog box saying:
"There is no disk in the drive. Please insert a disk into drive A:".
The title of the dialog is: "javaw.exe - No Disk".
When I press "Cancel" or "Continue" the file chooser opens regularly and I can browse the file system with no problem.
When I tried to use an application instead of the applet, this phenomenon disappears and the chooser opens without the dialog.
How can I avoid this?

[Paul Stevens]

I will try to remember what if anything we did when we encountered this error. I do remember that it happened on laptops when the last drive accessed before getting into the app was the cd/rom drive. The laptops had no A: at the time. The person I need to talk to is on vacation so I will have to check with him.

[Manfred Leonhardt]

Hi Amit,
Try to specify your harddrive (i.e., "C:\\" ) as a parameter into the constructor and see if that works.
Regards,
Manfred.

[Amit Rosner]

Hi Manfred and Paul!
No, it doesn't work.
As a matter of fact it shouldn't make any difference, because I never change my default directory, and moreover, I never change my default drive. I just call the constructor of JFileChooser, and I still get that modal dialog.
And as I mentioned, in an application it works fine. It only appears in a JApplet.
Please try to see if any of you has the same problem (start a new JApplet project and just try to create a JFileChooser object).
Amit.

[Manfred Leonhardt]

Hi Amit,
After some looking around, it seems that there is a Java bug in JFileChooser when used with a JApplet. It seems to be a problem with the SecurityManager and the CheckRead function. A workaround, I have figured out is shown below.

//
// Save current security manager
//
  SecurityManager sm = System.getSecurityManager();
//
// Override the checkRead method with Anon class
//
  System.setSecurityManager(
    new RMISecurityManager() 
    {
      public void checkRead(String s) {};
    });
  JFileChooser jfc = new JFileChooser();
  int rsp = jfc.showOpenDialog( ChooserApplet.this );
//
// Replace security manager with correct one again.
//
  System.setSecurityManager( sm );

Enjoy,
Manfred.

[Amit Rosner]

Hi again!
Thanks Manfred, it really solved the problem.
Still, I don't understand why that bug exists
and why Sun doesn't fix it.
I didn't find any documentation in Sun about it,
which makes it even more strange.
Amit.