Behavior difference when open file dialog from applet

Jonathan Lu luchsh at
Mon Apr 9 20:36:49 PDT 2012

Hi awt-dev,

I found a behavior difference when open file dialog from an applet, bug 
7160238  has been created for this issue.
Here's the tiny test case to helping reproduce the problem,

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import java.applet.Applet;
import java.awt.Button;
import java.awt.FileDialog;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class FileDialogTest extends Applet {
     public void init() {
         Button button = new Button("Open FileDialog");
         button.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent event) {
                 Frame f = new Frame();
                 FileDialog dialog = new FileDialog(f, "FileDialog");

Embeded it into an HTML document, test.html, then run appletviewer with 
following two commands,
appletviewer -J-Dsun.awt.disableGtkFileDialogs=true test.html
appletviewer -J-Dsun.awt.disableGtkFileDialogs=false test.html

The result will be different, -J-Dsun.awt.disableGtkFileDialogs=true 
will throw AccessControlException, but 
-J-Dsun.awt.disableGtkFileDialogs=false will continue to open a file dialog.

According to the specification:
The basic applet security model is an all or nothing proposition. If you 
get a security certificate, you can give the applet full access to the 
user's system. Without it, the applet has virtually no access at all.

Since file dialog displays the content of user's file system, so it 
absolutely needs file system read permmission, right? but for Gtk File 
Dialog, it just works fine without exceptions. I don't think this 
behavior is following the spec here, right? In OpenJDK's source code, 
GtkFileDialogPeer will create a native GTK file chooser widget and keep 
a native pointer, does this leave a breach to Java applet's security model?

- Jonathan

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