Question

I can’t compile this code because of several errors. Most of the errors are under the initUI() method, which was copied from a tutorial site. How do I fix this?

ActionEvent cannot be resolved to a type MenuGUI.java /Misc/src line 35 Java Problem

ActionListener cannot be resolved to a type MenuGUI.java /Misc/src line 34 Java Problem

KeyEvent cannot be resolved to a variable MenuGUI.java /Misc/src line 29 Java Problem

KeyEvent cannot be resolved to a variable MenuGUI.java /Misc/src line 32 Java Problem

The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (new ActionListener(){}) MenuGUI.java /Misc/src line 34 Java Problem

import javax.swing.*;
import java.awt.event.*;

public class MenuGUI extends JFrame{

private static final long serialVersionUID = 1L;

public static void main(String[] args)
{
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            MenuGUI ex = new MenuGUI();
            ex.setVisible(true);
        }
    });
}

public MenuGUI()
{
    initUI();
}

public 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_C);
    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);
}
}

Answer 1

I can compile the code without problems, but I get a runtime exception:

Do you have the picture in the right directory? In your code you try load an icon and when it not exist, you get a NullPointerException

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

Otherwise comment it out, and create the menu item without an icon

 JMenuItem eMenuItem = new JMenuItem("Exit");