create hot keys for JButton in java using swing

Question

I use the following code to create hot keys for the java form using swing. If I press ALT+N,ALT+R,ALT+1,ALT+2 the cursor moves to correct text fields and I enter the value in corresponding Text Fields. It works properly. My problem is, I have Save and exit JButtons in this form if. I press CTRL+S means the Save button will be selected at the same time If i press CTRL+X means the exit button will be selected. How to create mnemonics for JButton? How to do CTRL+S,CTRL+X this using the following code?

Thanks in advance.

package hotkeys;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
public class hotkey extends JFrame {
    public static void main(String arg[]) {
        JLabel Name = new JLabel("Name");
        JTextField tf1 = new JTextField(20);
        Name.setLabelFor(tf1);
        Name.setDisplayedMnemonic('N');


        JLabel Regno = new JLabel("RegNO");
        JTextField tf2 = new JTextField(20);
        Regno.setLabelFor(tf2);
        Regno.setDisplayedMnemonic('R');

        JLabel Mark1 = new JLabel("Mark1");
        JTextField tf3 = new JTextField(20);
        Mark1.setLabelFor(tf3);
        Mark1.setDisplayedMnemonic('1');

        JLabel Mark2 = new JLabel("Mark2");
        JTextField tf4 = new JTextField(20);
        Mark2.setLabelFor(tf4);
        Mark2.setDisplayedMnemonic('2');


        JButton b1 = new JButton("Save");
        JButton b2 = new JButton("eXit");


        JFrame f = new JFrame();
        JPanel p = new JPanel();

        p.add(Name);
        p.add(tf1);
        p.add(Regno);
        p.add(tf2);
        p.add(Mark1);
        p.add(tf3);
        p.add(Mark2);
        p.add(tf4);
        p.add(b1);
        p.add(b2);

        f.add(p);
        f.setVisible(true);
        f.pack();
    }
}

Answer 1

You need to register a keyBinding in the button's component inputmap. In code (repeating a subtle variant of what you have been told to do in your previous questions :-)

// create an Action doing what you want
Action action = new AbstractAction("doSomething") {

    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("triggered the action");
    }

};
// configure the Action with the accelerator (aka: short cut)
action.putValue(Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke("control S"));

// create a button, configured with the Action
JButton toolBarButton = new JButton(action);
// manually register the accelerator in the button's component input map
toolBarButton.getActionMap().put("myAction", action);
toolBarButton.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
        (KeyStroke) action.getValue(Action.ACCELERATOR_KEY), "myAction");