JFrame frame = new JFrame("Desktop");
JDesktopPane desktop = new JDesktopPane( );
for (int i = 0; i < 5; i++) {
JInternalFrame internal =
new JInternalFrame("Frame " + i, true, true, true, true);
internal.setSize(180, 180);
internal.setLocation(i * 20, i * 20);
internal.setVisible(true);
desktop.add(internal);
}
frame.setSize(300, 300);
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.setContentPane(desktop);
frame.setVisible(true);