public class MenuTest extends JPanel {
    private static final long serialVersionUID = -9209142740183347797L;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }

    private static void createAndShowGUI() {
        System.out.println("Created GUI on EDT? "+ SwingUtilities.isEventDispatchThread());

        JMenuBar bar = new JMenuBar();
        bar.add(new JMenu("Test1"));
        bar.add(new JMenu("Test2"));
        bar.add(new JMenu("Test3"));

        JFrame f = new JFrame("Swing Paint Demo 1");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new MenuTest());
        f.setJMenuBar(bar);
        f.pack();
        f.setVisible(true);


        JFrame f2 = new JFrame("Swing Paint Demo 2");
        f2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f2.add(new MenuTest());
        f2.setJMenuBar(bar);
        f2.pack();
        f2.setVisible(true);
    }
}