lil' error

When I run my applet I get:

Code:

---


Reading certificates from 1768 http://streetwars.comuf.com/StreetWars.jar | /home/deividas/.java/deployment/cache/6.0/14/301a4f8e-4fb2caec.idx
java.lang.reflect.InvocationTargetException
        at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:116)
        at sun.plugin2.applet.Plugin2Manager.runOnEDT(Plugin2Manager.java:3336)
        at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2905)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassCastException: start cannot be cast to java.applet.Applet
        at sun.plugin2.applet.Plugin2Manager$12.run(Plugin2Manager.java:2895)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:199)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception: java.lang.reflect.InvocationTargetException
java.lang.NullPointerException
        at sun.plugin2.applet.Plugin2Manager.findAppletJDKLevel(Plugin2Manager.java:2996)
        at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2947)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
        at java.lang.Thread.run(Thread.java:619)
Exception: java.lang.NullPointerException
java.lang.InterruptedException: sleep interrupted
        at java.lang.Thread.sleep(Native Method)
        at org.jvnet.lafwidget.animation.FadeTracker$FadeTrackerThread.run(FadeTracker.java:199)
java.lang.reflect.InvocationTargetException
        at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:116)
        at sun.plugin2.applet.Plugin2Manager.runOnEDT(Plugin2Manager.java:3336)
        at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2905)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassCastException: start cannot be cast to java.applet.Applet
        at sun.plugin2.applet.Plugin2Manager$12.run(Plugin2Manager.java:2895)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:199)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception: java.lang.reflect.InvocationTargetException
java.lang.NullPointerException
        at sun.plugin2.applet.Plugin2Manager.findAppletJDKLevel(Plugin2Manager.java:2996)
        at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2947)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
        at java.lang.Thread.run(Thread.java:619)
Exception: java.lang.NullPointerException
java.lang.reflect.InvocationTargetException
        at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:116)
        at sun.plugin2.applet.Plugin2Manager.runOnEDT(Plugin2Manager.java:3336)
        at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2905)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassCastException: start cannot be cast to java.applet.Applet
        at sun.plugin2.applet.Plugin2Manager$12.run(Plugin2Manager.java:2895)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:199)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception: java.lang.reflect.InvocationTargetException
java.lang.NullPointerException
        at sun.plugin2.applet.Plugin2Manager.findAppletJDKLevel(Plugin2Manager.java:2996)
        at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2947)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
        at java.lang.Thread.run(Thread.java:619)
Exception: java.lang.NullPointerException

---

My class:

Code:

---

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.net.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import org.jvnet.substance.skin.SubstanceBusinessBlueSteelLookAndFeel;

/**
 *
 * @author deividas
 */
public class start extends JPanel {



    boolean loggedIn = false;

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                createAndShowUI();
            }
        });
    }

    public start() {

        UIManager UIManager = new UIManager();
        try {
            UIManager.setLookAndFeel("org.jvnet.substance.skin.SubstanceBusinessBlueSteelLookAndFeel");
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(start.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            Logger.getLogger(start.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            Logger.getLogger(start.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnsupportedLookAndFeelException ex) {
            Logger.getLogger(start.class.getName()).log(Level.SEVERE, null, ex);
        }

        setPreferredSize(new Dimension(955, 605));
        setLayout(new BorderLayout());
        //----PANELS----//

        //top panel
        JPanel topPanel = new JPanel(new GridLayout(1, 0, 5, 5));
        topPanel.setOpaque(false);
        add(topPanel, BorderLayout.NORTH);
        //panel1
        JPanel panel1 = new JPanel(new GridLayout(1, 0, 5, 5));
        panel1.setOpaque(false);
        JLabel welcomeL = new JLabel("<html><br><br><br><br><br><br>Welcome to Street Wars.</html>");
        panel1.add(welcomeL);
        //---END OF PANELS---//

        //---TABS---//

        //tab1
        JTabbedPane tabbedPane = new JTabbedPane();
        tabbedPane.addTab("Welcome", panel1);
        tabbedPane.setMnemonicAt(0, KeyEvent.VK_F1);
        topPanel.add(tabbedPane);
    }

    private static void createAndShowUI() {


        JFrame frame = new JFrame("Street Wars");
        frame.getContentPane().add(new start());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setResizable(false);
        start start = new start();
        frame.setJMenuBar(start.createMenuBar());

    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);

        URL url = this.getClass().getResource("/images/background.jpg");
        Image img = Toolkit.getDefaultToolkit().getImage(url);

        g.drawImage(img, 0, 0, this);
    }

    //menubar
    public JMenuBar createMenuBar() {

        JMenuBar menuBar;
        JMenu menu;
        final JMenuItem loginItem;
        final JMenuItem registerItem;
        final JMenuItem logoutItem;

        //Create the menu bar.
        menuBar = new JMenuBar();
        menuBar.setOpaque(true);
        //Build the first menu.
        menu = new JMenu("File");
        menuBar.add(menu);

        //a group of JMenuItems

        loginItem = new JMenuItem("Login");
        menu.add(loginItem);
        registerItem = new JMenuItem("Register");
        menu.add(registerItem);
        logoutItem = new JMenuItem("Logout");
        logoutItem.setVisible(false);
        menu.add(logoutItem);
        menu.addSeparator();

        loginItem.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                if (loggedIn == false) {
                    JOptionPane.showMessageDialog(null, "loggedIn should be set to TRUE");
                    loggedIn = true;
                }

                if (loggedIn == true) {
                    JOptionPane.showMessageDialog(null, "loggedIn is " + loggedIn + ".");
                    loginItem.setVisible(false);
                    registerItem.setVisible(false);
                    logoutItem.setVisible(true);
                }
            }
        });

        return menuBar;
    }
}

---

put

"Caused by: java.lang.ClassCastException: start cannot be cast to java.applet.Applet"

into Google, and you'll be surprised how many people have problems with this...

I've changed extends JPanel to extends JApplet.