Java Swing MenuBar

gistfile1.java

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.SwingUtilities;

public class Example extends JFrame {

    public Example() {
        initUI();
    }

    public final void initUI() {

        JMenuBar menubar = new JMenuBar();
        ImageIcon icon = new ImageIcon(getClass().getResource("exit.png"));

        JMenu file = new JMenu("File");
        file.setMnemonic(KeyEvent.VK_F);

        JMenuItem eMenuItem = new JMenuItem("Exit", icon);
        eMenuItem.setMnemonic(KeyEvent.VK_E);
        eMenuItem.setToolTipText("Exit application");
        eMenuItem.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                System.exit(0);
            }
        });

        file.add(eMenuItem);

        menubar.add(file);

        setJMenuBar(menubar);

        setTitle("Simple menu");
        setSize(300, 200);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                Example ex = new Example();
                ex.setVisible(true);
            }
        });
    }
}