JApplet with JFrame fails to load in browser

Question

I have been making a Java program that runs a JApplet the program operates perfectly in NetBeans (the Java development kit), but when I run it in the browser, it fails to load.
The code is...
import java.awt.*;
import javax.swing.*;
public class CalculatorMain extends javax.swing.JApplet {
private Difficulty difficulty = new Difficulty();
private Troop[] troop = new Troop[7];
private Army army = new Army(troop);
private Calculator calculator = new Calculator(difficulty, army);
private CalculatorListener listener;
public void init(){
JPanel supreme = new JPanel();
supreme.setLayout(new BorderLayout());
for (byte i = 0; i < 7; i++) {troop[i] = new Troop();}
DifficultyPanel diffpanel = new DifficultyPanel(difficulty);
ArmyPanel armypanel = new ArmyPanel(troop);
JButton calbut = new JButton("Calculate Experience");
JLabel xpDisplay = new JLabel(" ");
CalculatorPanel calpanel = new CalculatorPanel(calculator, calbut, xpDisplay);
JFrame frame = new JFrame();
listener = new CalculatorListener(xpDisplay, calculator, diffpanel, armypanel, calpanel);
calbut.addActionListener(listener);
supreme.add(diffpanel, BorderLayout.WEST);
supreme.add(armypanel, BorderLayout.CENTER);
supreme.add(calpanel, BorderLayout.SOUTH);
frame.add(supreme);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
As I said, it does not work in the web browser (which is Internet Explorer 6.0). In the information window I open, the message is...
Java Plug-in 1.5.0_06
Anv�nder JRE-version 1.5.0_06 Java HotSpot(TM) Client VM
java.security.AccessControlException: access denied (java.lang.RuntimePermission exitVM)
     at java.security.AccessControlContext.checkPermission(Unknown Source)
     at java.security.AccessController.checkPermission(Unknown Source)
     at java.lang.SecurityManager.checkPermission(Unknown Source)
     at java.lang.SecurityManager.checkExit(Unknown Source)
     at javax.swing.JFrame.setDefaultCloseOperation(Unknown Source)
     at CalculatorMain.init(CalculatorMain.java:31)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
Exception in thread "thread applet-CalculatorMain.class" java.lang.NullPointerException
     at sun.plugin.util.GrayBoxPainter.showLoadingError(Unknown Source)
     at sun.plugin.AppletViewer.showAppletException(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
Any idea what might be wrong?

Answer 1

If you look at your error message you'll see...
java.security.AccessControlException: access deniedAh. Problem # 1 caused at
     at CalculatorMain.init(CalculatorMain.java:31)Problem #2
java.lang.NullPointerExceptionat
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)So it says it can't display the init error message. That's ok this should go away when you fix bug #1