MDI Swing

import java.awt.<em>;

import java.awt.event.</em>;

import javax.swing.*;

public class Teste extends JIternalFrame

{

Teste()

{   … }

public static void main( String args[] )

{ JInternalFrame a=new Teste();

a.show();

}

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


  public class MenuFrame extends JFrame implements ActionListener, MouseListener, MouseMotionListener {
	   JMenu menu;
	   JMenuItem exemp                                                   = new JMenuItem("JInternalFrame");
	   JPopupMenu popup                                                  = new JPopupMenu();
	   String[] nomePopup                                                = {"JInternalFrame","Sair"};
	   JMenuItem[] menuPopup                                             = new JMenuItem[2];
	  	Color color                                                       = new Color(200,200,200);//Color(29,140,194);
	   JButton botaoSair                                                 = new JButton("A");
	   static JButton botaoBackup                                        = new JButton("B");
   	static JButton botaoNovo                                          = new JButton("C");
    Container c;
    static JMenuBar menuBar;
    JDesktopPane desktop                                              = new JDesktopPane();
    static final Integer DOCLAYER                                     = new Integer(5);
    static final Integer TOOLLAYER                                    = new Integer(6);
    static final Integer HELPLAYER                                    = new Integer(7);

    public MenuFrame() {
      super("JInternalFrame");
      final int inset                                                 = 60;
      Dimension screenSize                                            = Toolkit.getDefaultToolkit().getScreenSize();
   		 setBounds ( inset, inset, screenSize.width - inset*2, screenSize.height - inset*2 );
		    buildContent();
		    buildMenus();
		    this.addWindowListener(new WindowAdapter() {
	       public void windowClosing(WindowEvent e) {
				      quit();
			     }
      });
		    System.out.println("Iniciando Menu Principal");
		    show();
   	}

    protected void buildMenus() {
      menuBar                                                         = new JMenuBar();
	    	menuBar.setOpaque(true);
    		menu                                                            = buildFileMenu();
    		menuBar.add(menu);
    		setJMenuBar(menuBar);
    		builPopup();
    }

  	 public void builPopup() {
		    for(int i=0; i<2; i++) {
			     menuPopup[i]                                                  = new JMenuItem(nomePopup[i]);
			     if(i == 1)
				      popup.addSeparator();
			     popup.add(menuPopup[i]);
			     menuPopup[i].addActionListener(this);
		    }
	   }    
    

    protected JMenu buildFileMenu() {
    		menu = new JMenu("Exemplo");
	    	menu.addActionListener(this);
		    menu.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
	   		exemp.addActionListener(new ActionListener() {
	    	  public void actionPerformed(ActionEvent e) {
					     openWindow();
			    	}
      });
    		menu.add(exemp);
    		return menu;
	   }

    protected void buildContent() {
      desktop.addMouseListener(this);
      desktop.addMouseMotionListener(this);
      getContentPane().add(desktop);
      desktop.setBackground(color);
    }

    public void quit() {
		    int result                                                      = JOptionPane.showConfirmDialog(null,"Deseja realmente Sair?", "Saindo", JOptionPane.WARNING_MESSAGE);
		    if (result == JOptionPane.YES_OPTION) {
		      System.out.println("Fechando Menu Principal");		
   			  System.exit(0);
		    }
    }

    public void openWindow() {
    		JInternalFrame internal1                                        = new sobre();
		    desktop.add(internal1, HELPLAYER);
		    try { 
	    	  internal1.setVisible(true);
	    	  internal1.setSelected(true); 
		    }	catch (java.beans.PropertyVetoException e2) {}
      }

    public void actionPerformed(ActionEvent e) {
    	 if(e.getSource() == menuPopup[0])
    		  openWindow();
    	 if(e.getSource() == menuPopup[1])
    		  quit();
     	if(e.getSource() == botaoSair)
      		quit();
    }	

	   public void mouseClicked(MouseEvent e) {
	   }

   	private void checkForTriggerEvent(MouseEvent e) {
    		if(e.isPopupTrigger())
			     popup.show(e.getComponent(), e.getX(), e.getY());
   	}

   	public void mouseReleased(MouseEvent e) {
		    if(e.getSource() == desktop) {
			     checkForTriggerEvent(e);	
		    }
   	}

	   public void mouseEntered(MouseEvent e) {
	   }
		
	   public void mouseExited(MouseEvent e) {
   	}
	   public void mousePressed(MouseEvent e) {
	    	if(e.getSource() == desktop) {
		     	checkForTriggerEvent(e);	
		    }		
	   }
    public void mouseDragged(MouseEvent e) {
    }
   	public void mouseMoved(MouseEvent e) {
	   }
	
	   public static void main(String[] args) {
		    try {
					  	UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel" );
  				} catch (Exception e) { 
          System.out.println("Teste");
      }
		    new MenuFrame();	
	   }
  }