Help with FullScreen mode

Question

     public static void main(String []args)
          GraphicsEnvironment myEnvironment = GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice myDevice = myEnvironment.getDefaultScreenDevice();
          JFrame mainFrame = new JFrame();
          mainFrame.pack();
         myDevice.setFullScreenWindow(mainFrame);
         mainFrame.setVisible(true);
     }I did that and compiled it and it there were no errors but when I put in
mainFrame.setUndecorated(true);It didn't work. can someone help me understand how to make a screen that is undecorated that fits the whole screen. Thanks in advance.

Answer 1

This is my code so far and it still is decorated. I fixed all the errors when compiling it but it still is decorated. Can anyone help me?
import javax.swing.*;
import java.io.*;
import java.awt.*;
public class Blob extends JFrame
     public static void createAndShowGUI()
          JFrame frame = new JFrame();
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          Dimension fullScreen = Toolkit.getDefaultToolkit().getScreenSize();
          frame.setBounds(0,0,fullScreen.width,fullScreen.height);
          frame.setUndecorated(true);
          frame.pack();
         frame.setVisible(false);
     public static void main(String []args)
         javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
}I also tried this....
public static void main(String []args)
          GraphicsEnvironment myEnvironment =   GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice myDevice = myEnvironment.getDefaultScreenDevice();
          JFrame mainFrame = new JFrame();
          mainFrame.pack();
         myDevice.setFullScreenWindow(mainFrame);
         mainFrame.setVisible(true);
     }and added the
setUndecorated(true);before it was displayed and it too was still decorated.