Display Message with radio buttons - Java

MainPage.java

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

public class MainPage
{
     public static void main(String[] args)
     {
          final JFrame frame = new JFrame("JRadioButton Demo");
          // implement ItemListener interface
          class MyItemListener implements ItemListener
          {
               public void itemStateChanged(ItemEvent ev)
               {
                    boolean selected = (ev.getStateChange() == ItemEvent.SELECTED);
                    AbstractButton button = (AbstractButton) ev.getItemSelectable();
                    String command = button.getActionCommand();
                    // build message
                    String state;
                    if (selected)
                    {
                         state = "selected";
                    }
                    else
                    {
                         state = "unselected";
                    }
                    String message;
                    if (command.equals("Java"))
                    {
                         message = "The Java option has been " + state;
                    }
                    else if (command.equals("ASP"))
                    {
                         message = "The ASP.Net option has been " + state;
                    } else
                    {
                         message = "The SQL option has been " + state;
                    }
                    // show dialog
                    JOptionPane.showMessageDialog(frame, message);
               }
          }

          // creates radio button and set corresponding action
          // commands
          JRadioButton rdbJava = new JRadioButton("Java");
          rdbJava.setActionCommand("Java");

          JRadioButton rdbASP = new JRadioButton("ASP.Net");
          rdbASP.setActionCommand("ASP");

          JRadioButton rdbSQL = new JRadioButton("SQL");
          rdbSQL.setActionCommand("SQL");

          // add event handler
          MyItemListener myItemListener = new MyItemListener();
          rdbJava.addItemListener(myItemListener);
          rdbASP.addItemListener(myItemListener);
          rdbSQL.addItemListener(myItemListener);

          // add radio buttons to a ButtonGroup
          final ButtonGroup group = new ButtonGroup();
          group.add(rdbJava);
          group.add(rdbASP);
          group.add(rdbSQL);

          // Frame setting
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setSize(300, 200);
          Container cont = frame.getContentPane();

          cont.setLayout(new GridLayout(0, 1));
          cont.add(new JLabel("Please choose your favorite language: "));
          cont.add(rdbJava);
          cont.add(rdbASP);
          cont.add(rdbSQL);

          frame.setVisible(true);
     }
}