import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; /** This program demonstrates how to install an action listener. */ public class ButtonViewer { public static void main(String[] args) { JFrame frame = new JFrame(); JButton button = new JButton("Click me!"); frame.add(button); button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { System.out.println(event); System.out.println("I was clicked."); } }); frame.setSize(FRAME_WIDTH, FRAME_HEIGHT); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } private static final int FRAME_WIDTH = 300; private static final int FRAME_HEIGHT = 360; }