Troubleshooting a Swing Radio Buttons Applet

Question

I have to create a Swing applet for a school assignment, and was given a link (http://java.sun.com/docs/books/tutorial/uiswing/components/index.html) to look at various Swing tutorials and use one of them to create a unique Java applet. I chose to follow the code for the How To Use Radio Buttons tutorial. I read through the code and typed it up while changing things so that they would match my pictures. The code I have is

package components;

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

public class OSButtons extends JPanel implements ActionListener {

    static String windowsString = "Windows";
    static String linuxString = "Linux";
    static String macString = "Mac";

    JLabel picture;

    public OSButtons() {
        super(new BorderLayout());

        JRadioButton windowsButton = new JRadioButton(windowsString);
        windowsButton.setMnemonic(KeyEvent.VK_W);
        windowsButton.setActionCommand(windowsString);
        windowsButton.setSelected(true);

        JRadioButton linuxButton = new JRadioButton(linuxString);
        linuxButton.setMnemonic(KeyEvent.VK_L);
        linuxButton.setActionCommand(linuxString);

        JRadioButton macButton = new JRadioButton(macString);
        macButton.setMnemonic(KeyEvent.VK_M);
        macButton.setActionCommand(macString);

        ButtonGroup group = new ButtonGroup();
        group.add(windowsButton);
        group.add(linuxButton);
        group.add(macButton);

        windowsButton.addActionListener(this);
        linuxButton.addActionListener(this);
        macButton.addActionListener(this);

        picture = new JLabel(createImageIcon("images/" + windowsString + ".gif"));
        picture.setPreferredSize(new Dimension(200, 150));

        JPanel radioPanel = new JPanel(new GridLayout(0, 1));
        radioPanel.add(windowsButton);
        radioPanel.add(linuxButton);
        radioPanel.add(macButton);

        add(radioPanel, BorderLayout.LINE_START);
        add(picture, BorderLayout.CENTER);
        setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
    }

    public void actionPerformed(ActionEvent e) {
        picture.setIcon(createImageIcon("images/" + e.getActionCommand() + ".gif"));
    }

    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = OSButtons.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    private static void createAndShowGUI() {
        JFrame frame = new JFrame("OSButtons");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JComponent newContentPane = new RadioButtonDemo();
        newContentPane.setOpaque(true);
        frame.setContentPane(newContentPane);

        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

I hope that's readable. Anyways, I compiled the code and it came up with these errors:

I really have no idea how to proceed from here as far as fixing these, this assignment was kind of thrown onto me and I had to research Swing, SWT, and AWT completely on my own. Any help that could be offered would be greatly appreciated.

Answer 1

Change...

picture = newJLabel(createImageIcon("images/"+ windowsString + ".gif"));

to...

picture = new JLabel(createImageIcon("images/"+ windowsString + ".gif"));

Change

radiopanel.add(macButton);

to...

radioPanel.add(macButton);

Java is case sensitve, variable names case must match

This...

JComponent newContentPane = new RadioButtonDemo();

I suspect is a copy/paste error. You change the class name of the original code, but forgot to change any references to it.

Try...

JComponent newContentPane = new OSButtons();

Instead

Update

Okay. Let's assume that you have your source files in C:\Users\Keith\Desktop\components.

At the command prompt your would compile them by using something like...

C:\> cd C:\Users\Keith\Desktop
C:\Users\Keith\Desktop> javac components.OSButtons.java
C:\Users\Keith\Desktop> java components.OSButtons

There is a direct coalition between the package name and the expected directory of the class files.