import java.awt.*;
import java.awt.event.*;

class MenuFrame1 extends    Frame
                 implements ActionListener
{
   public MenuFrame1()
   {
      MenuBar   mb=new MenuBar();        
      Menu      m1=new Menu("ALFA"),         m2=new Menu("BETA"),         m3=new Menu("GAMMA");               
      MenuItem m11=new MenuItem("ALFA-A"),  m21=new MenuItem("BETA-A"),  m31=new MenuItem("GAMMA-A"),
               m12=new MenuItem("ALFA-B"),  m22=new MenuItem("BETA-B"),
               m13=new MenuItem("ALFA-C"),  m23=new MenuItem("BETA-C"),
               m14=new MenuItem("USCITA"),  m24=new MenuItem("BETA-D");                                                                                                             
               m11.addActionListener(this); m21.addActionListener(this); m31.addActionListener(this);
               m12.addActionListener(this); m22.addActionListener(this); 
               m13.addActionListener(this); m23.addActionListener(this); 
               m14.addActionListener(this); m24.addActionListener(this);               
               mb.add(m1);                  mb.add(m2);                  mb.add(m3);     
               m1.add(m11);                 m2.add(m21);                 m3.add(m31);
               m1.add(m12);                 m2.add(m22);
               m1.add(m13);                 m2.add(m23);
               m1.add(m14);                 m2.add(m24);

      this.setMenuBar(mb); 
      this.setSize(640, 480);
      this.setVisible(true);
   }

   public void actionPerformed(ActionEvent ae)
   {
      String nome=ae.getActionCommand();
      String msg ="";

           if(nome.equals("ALFA-A")  ) msg="...ALFA...A...";
      else if(nome.equals("ALFA-B")  ) msg="...ALFA...B...";
      else if(nome.equals("ALFA-C")  ) msg="...ALFA...C...";
      else if(nome.equals("USCITA")  ) System.exit(0);
      else if(nome.equals("BETA-A")  ) msg="...BETA...A...";
      else if(nome.equals("BETA-B")  ) msg="...BETA...B...";
      else if(nome.equals("BETA-C")  ) msg="...BETA...C...";
      else if(nome.equals("BETA-D")  ) msg="...BETA...D...";
      else if(nome.equals("GAMMA-A") ) msg="...GAMMA..A...";
      else                             msg="Evento non previsto!";

      System.out.println(msg); 
   }
   public static void main(String args[])
   {
      MenuFrame1 mf=new MenuFrame1();
   }
}

1. MenuBar, add(), setMenuBar()

2. Menu, add(), addActionListener(), actionPerformed(), getActionCommand()