Nova Janela

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class DesktopTest extends JFrame {

   private JDesktopPane theDesktop;

   public DesktopTest()
   {
      super( "Using a JDesktopPane" );

      JMenuBar bar = new JMenuBar();
      JMenu addMenu = new JMenu( "Add" );
      JMenuItem newFrame = new JMenuItem( "Internal Frame" );

      addMenu.add( newFrame );
      bar.add( addMenu );

      setJMenuBar( bar );

      theDesktop = new JDesktopPane();
      getContentPane().add( theDesktop );

      newFrame.addActionListener(

         new ActionListener() {

            public void actionPerformed( ActionEvent e )
            {
               JInternalFrame frame = new JInternalFrame(

                  "InternalFrame", true, true, true, true

               );

               Container box = frame.getContentPane(  );
               MyPanel panel = new MyPanel();
               box.add( panel, BorderLayout.CENTER );

               frame.pack();

               theDesktop.add( frame );
               frame.setVisible( true );
            }

         }

      );

      setSize( 600, 400 );
      show();
   }

   public static void main( String args[] )
   {
      DesktopTest win = new DesktopTest();

      win.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   }

   class MyPanel extends JPanel {

      private ImageIcon imageIcon;

      public MyPanel()
      {
         imageIcon = new ImageIcon( "imagem.gif" );
      }

      public void paintComponent( Graphics g )
      {
         super.paintComponent( g );
         imageIcon.paintIcon( this, g, 0, 0 );
      }

      public Dimension getPreferredSize()
      {
         return new Dimension( imageIcon.getIconWidth(), imageIcon.getIconHeight() );
      }

   }

}