Java tutorial
import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import javax.swing.JCheckBox; import javax.swing.JFrame; import javax.swing.JPanel; public class Main extends JPanel implements ItemListener { public Main() { JCheckBox cb = new JCheckBox("www.java2s.com"); cb.addItemListener(this); add(cb); } public void itemStateChanged(ItemEvent ie) { System.out.println(ie.getID() == ItemEvent.ITEM_FIRST); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.add(new Main()); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(200, 200); frame.setVisible(true); } }