some questions about setMnemonic

I have the code:

public class MenuBar extends JFrame {

    public MenuBar() {
        initUI();
    }

    public final void initUI() {

        JMenuBar menubar = new JMenuBar();

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

        JMenuItem eMenuItem = new JMenuItem("Exit");
        JMenuItem oMenuItem = new JMenuItem("Open Another");
        eMenuItem.setMnemonic(KeyEvent.VK_E);
        oMenuItem.setMnemonic(KeyEvent.VK_O);
        eMenuItem.setToolTipText("Exit application");
        oMenuItem.setToolTipText("Open another Window");
        eMenuItem.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                System.exit(0);
            }
        });
        oMenuItem.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                main(null);
            }
        });

        file.add(eMenuItem);
        file.add(oMenuItem);
        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() {
                MenuBar ex = new MenuBar();
                ex.setVisible(true);
            }
        });
    }
}

it works fine but I had a question about setMnemonic. How would you go about making the Mnemonic for eMenuItem just to press E, as opposed to Alt + E? Thanks for any and all help! (Please not I left imports out intentially, for length issues)