Program Challenge

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

public class Locks {
   public static void main(String args[]) {
     Runnable runner = new Runnable() {
       public void run() {
         JFrame frame = new JFrame("Locks");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

         JTextArea textArea = new JTextArea();
         JScrollPane scrollPane = new JScrollPane(textArea);
         frame.add(scrollPane, BorderLayout.CENTER);

         // Create status bar with one label per watched locking key
         JPanel statusBar = new JPanel(new GridLayout(1, 3));
         final JLabel numLock = new JLabel("", JLabel.CENTER);
         statusBar.add(numLock);
         final JLabel capsLock = new JLabel("", JLabel.CENTER);
         statusBar.add(capsLock);
         final JLabel scrollLock = new JLabel("", JLabel.CENTER);
         statusBar.add(scrollLock);
     frame.add(statusBar, BorderLayout.SOUTH);

         setKeyStatus(numLock, KeyEvent.VK_NUM_LOCK, "Num");
         setKeyStatus(capsLock, KeyEvent.VK_CAPS_LOCK, "Caps");
         setKeyStatus(scrollLock, KeyEvent.VK_SCROLL_LOCK, "Scroll");

         KeyListener listener = new KeyAdapter() {
           public void keyPressed(KeyEvent keyEvent) {
             if (keyEvent.getKeyCode() == KeyEvent.VK_NUM_LOCK) {
               setKeyStatus(numLock, KeyEvent.VK_NUM_LOCK, "Num");
             } else if (keyEvent.getKeyCode() == KeyEvent.VK_CAPS_LOCK) {
               setKeyStatus(capsLock, KeyEvent.VK_CAPS_LOCK, "Caps");
             } else if (keyEvent.getKeyCode() == KeyEvent.VK_SCROLL_LOCK) {
               setKeyStatus(scrollLock, KeyEvent.VK_SCROLL_LOCK, "Scroll");
             }
           }
         };
         textArea.addKeyListener(listener);

         frame.setSize(250, 150);
         frame.setVisible(true);
       }
     };
     EventQueue.invokeLater(runner);
   }

   private static void setKeyStatus(JLabel label, int key, String prefix) {
     Toolkit toolkit = Toolkit.getDefaultToolkit();
     String status = (toolkit.getLockingKeyState(key) ? "On" : "Off");
     label.setText(prefix+status);
   }
}