Java JFrame add JToolBar

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JToolBar;

public class Main extends JFrame {
   public static final String ENABLE = "ENABLE";
   public static final String DISABLE = "DISABLE";

   private JToolBar toolBar = new JToolBar();
   private JMenuBar menuBar = new JMenuBar();
   private JMenu testMenu = new JMenu("Test");
   private MyAction theAction = new MyAction();
   private JMenuItem disableActionItem = new JMenuItem("Disable the Action");

   public Main() {
      this.setJMenuBar(menuBar);
      menuBar.add(testMenu);/*ww w .j  ava2s. co m*/

      testMenu.add(theAction);
      toolBar.add(theAction);

      disableActionItem.setActionCommand(DISABLE);
      testMenu.add(disableActionItem);
      disableActionItem.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            if (e.getActionCommand().equals(DISABLE)) {
               theAction.setEnabled(false);
               disableActionItem.setText("Enable the Action");
               disableActionItem.setActionCommand(ENABLE);
            } else {
               theAction.setEnabled(true);
               disableActionItem.setText("Disable the Action");
               disableActionItem.setActionCommand(DISABLE);
            }
         }
      });
      this.getContentPane().add(toolBar, BorderLayout.NORTH);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      this.setSize(320, 200);
      this.setVisible(true);
   }

   public static void main(String[] args) {
      Main t = new Main();
   }
}

class MyAction extends AbstractAction {
   public MyAction() {
      super("Change Color");
   }
   public void actionPerformed(ActionEvent e) {
      System.out.println("action");
   }
}