[java] setMnemonic JButtons!

import java.awt.event.ActionEvent;import java.awt.event.KeyEvent;import javax.swing.AbstractAction;import javax.swing.Action;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.KeyStroke;import javax.swing.SwingUtilities;public class ActionExample {    public static void main(String[] args) {        new ActionExample();    }    public ActionExample(){        SwingUtilities.invokeLater(new Runnable(){            public void run(){                initGui();            }        });    }    private void initGui(){        //Prepare the frame        JFrame frame = new JFrame("Action Example");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Prepare a panel to hold the two buttons        JPanel panel = new JPanel();        frame.getContentPane().add(panel);        //Set up button1        JButton button1 = new JButton("Button1 (ctrl+1)");        //Create an action for buttons1.        //I could have created one action for both buttons and used e.getSource() to find which button was the source of the event.        Action button1Action = new AbstractAction(){            public void actionPerformed(ActionEvent e) {                JOptionPane.showMessageDialog(null, "You activated button1");            }        };        //Set up the mappings so that key events get mapped to actions        //The string can actually be any object that is different for each action. I just used these strings for ease since "b1a" is different than "b2a".        button1.getInputMap(JOptionPane.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_1, KeyEvent.CTRL_DOWN_MASK), "b1a");        button1.getActionMap().put("b1a", button1Action);        //An action is a subclass of ActionListener, so we can do the following:        button1.addActionListener(button1Action);        //Add the button to the panel        panel.add(button1);        //Set up button2        JButton button2 = new JButton("Button2 (ctrl+2)");        Action button2Action = new AbstractAction(){            public void actionPerformed(ActionEvent e) {                JOptionPane.showMessageDialog(null, "You activated button2");            }        };        button2.getInputMap(JOptionPane.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_2, KeyEvent.CTRL_DOWN_MASK), "b2a");        button2.getActionMap().put("b2a", button2Action);        button2.addActionListener(button2Action);        panel.add(button2);        //Add the finishing touches on the frame        frame.pack();        frame.setVisible(true);    }}