This Java tip illustrates a method of creating a group of buttons in an application. A ButtonGroup is usually created when developer wants to provide a list of choices to users and wants him to choose one from them. If user selects second choice his first choice will be deselected.

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

public class SimpleButtonGroupExample {
    
    public static void main(String[] args) {
        // Some choices
        JRadioButton choice1, choice2, choice3;
        choice1 = new JRadioButton("Bach: Well Tempered Clavier, Book I");
        choice1.setActionCommand("bach1");
        choice2 = new JRadioButton("Bach: Well Tempered Clavier, Book II");
        choice2.setActionCommand("bach2");
        choice3 = new JRadioButton("Shostakovich: 24 Preludes and Fugues");
        choice3.setActionCommand("shostakovich");
        
        // A group, to ensure that we only vote for one.
        final ButtonGroup group = new ButtonGroup();
        group.add(choice1);
        group.add(choice2);
        group.add(choice3);
        
        // A simple ActionListener, showing each selection 
        // using the ButtonModel
        class VoteActionListener implements ActionListener {
            public void actionPerformed(ActionEvent ev) {
                String choice = group.getSelection().getActionCommand();
                System.out.println("ACTION Choice Selected: " + choice);
            }
        }
        
        // A simple ItemListener, showing each selection and deselection
        class VoteItemListener implements ItemListener {
            public void itemStateChanged(ItemEvent ev) {
                boolean selected = (ev.getStateChange() == 
                        ItemEvent.SELECTED);
                
                AbstractButton button = 
                        (AbstractButton)ev.getItemSelectable();
                
                System.out.println("ITEM Choice Selected: " + selected +
                        ", Selection: " + button.getActionCommand());
            }
        }
        
        // Add listeners to each button
        ActionListener alisten = new VoteActionListener();
        choice1.addActionListener(alisten);
        choice2.addActionListener(alisten);
        choice3.addActionListener(alisten);
        
        ItemListener ilisten = new VoteItemListener();
        choice1.addItemListener(ilisten);
        choice2.addItemListener(ilisten);
        choice3.addItemListener(ilisten);
        
        // Throw everything together
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container c = frame.getContentPane();
        c.setLayout(new GridLayout(0, 1));
        c.add(new JLabel("Vote for your favorite prelude & fugue cycle"));
        c.add(choice1);
        c.add(choice2);
        c.add(choice3);
        frame.pack();
        frame.setVisible(true);
    }
}