/* * Simple1.java - an example of handling events. *    For this example, we implement a single ActionListener *    which is then used to catch all events. A series of ifs *    are used to determine which object caused the event. */import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Simple1{    private static JFrame frame;   // static so main can use it    private static JPanel myPanel; // panel for the contentPane    private JButton button1;       // Define out here to make    private JButton button2;       // visible to ActionListener        public Simple1()               // Construct, build GUI    {        // Create a panel        myPanel = new JPanel();        // Create the buttons.        button1 = new JButton("Button 1");  // Create buttons        button2 = new JButton("Button 2");        SimpleListener ourListener = new SimpleListener();	// Set action listener for both buttons to share        button1.addActionListener(ourListener);        button2.addActionListener(ourListener);        myPanel.add(button1);	// Adds to current JFrame        myPanel.add(button2);    }    private class SimpleListener implements ActionListener    {    /*     * We will use a simple inner class to implement an     * ActionListener to use to get the button events. We     * could have instead used the Simple1 class itself to     * implement ActionListener instead, but this way is      * more consistent with the other examples.     */        public void actionPerformed(ActionEvent e)        {            // We will use getActionCommand to get the button            // name, but we could use getSource() instead and            // the if tests would then be like:            // if (e.getSource() == button1)  etc.            String buttonName = e.getActionCommand();            if (buttonName.equals("Button 1"))                JOptionPane.showMessageDialog(frame,                                            "Button 1 pressed");            else if (buttonName.equals("Button 2"))                JOptionPane.showMessageDialog(frame,                                            "Button 2 pressed");            else                JOptionPane.showMessageDialog(frame,                                            "Unknown event");        }    }    public static void main(String s[])    {        Simple1 gui = new Simple1(); // Create Simple1 component                frame = new JFrame("Simple1");  // JFrame for the panel        // Standard idiom to catch close event        frame.addWindowListener(new WindowAdapter() {             public void windowClosing(WindowEvent e)              {System.exit(0);} });        frame.getContentPane().add(myPanel);        frame.pack();                  // Ready to go        frame.setVisible(true);    }}