I found this at the file you gave me:
GraphicsDevice device = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
modes = device.getDisplayModes();
I decided to try this:
GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
for(DisplayMode mode : gd.getDisplayModes()) {
System.out.println(mode.getWidth() + " * " + mode.getHeight());
}
And it outputs this:
1366 * 768
1366 * 768
1280 * 720
1024 * 768
800 * 600
640 * 480
Does this help on something?