Run applet as application

Question

Hi To All,
I'm converting a Applet into Application.
All the things are runing well but when my Applet gets to try the access getDocumentBase() method
its giving a nullPointerException
My all code is written below please help me to find out the problem
import java.awt.Frame;
import java.awt.event.*;
import java.awt.Dimension;
import java.applet.Applet;
// Applet to Application Frame window
public class AppletFrame extends Frame implements java.awt.event.WindowListener
public static void startApplet(String className, String title,String args[])
{ Dimension appletSize;
try
// create an instance of your applet class
myApplet = (Applet) Class.forName(className).newInstance();
catch (ClassNotFoundException e)
{ System.out.println("AppletFrame " + e);
return;
catch (InstantiationException e)
System.out.println("AppletFrame " + e);
return;
} catch (IllegalAccessException e)
System.out.println("AppletFrame " + e);
return;
} // initialize the applet myApplet.init();
myApplet.start();
AppletFrame f = new AppletFrame(title);
f.add("Center", myApplet);
f.addWindowListener(f);
appletSize = myApplet.getSize();
f.pack();
f.setSize(appletSize);
f.show();
public AppletFrame(String name)
{ super(name);
} public void windowClosing(java.awt.event.WindowEvent ev)
{ myApplet.stop();
myApplet.destroy();
java.lang.System.exit(0);
} public void windowClosed(java.awt.event.WindowEvent ev) {}
public void windowActivated(java.awt.event.WindowEvent ev) {}
public void windowDeactivated(java.awt.event.WindowEvent ev) {}
public void windowOpened(java.awt.event.WindowEvent ev) {}
public void windowIconified(java.awt.event.WindowEvent ev) {}
public void windowDeiconified(java.awt.event.WindowEvent ev) {}
private static Applet myApplet;
public static void main(String args[]){
startApplet("appletImageBook.appletImage.Standalone2","XApplets",args);
====================================================
And Standalone2.java is
public class Standalone2 extends Applet {
Image img ;
public void init()
{ add(new Button("Standalone Applet Button"));
img = getImage(getDocumentBase(),"images/office1.jpg");
public void paint(Graphics g) {
g.drawImage(img,0,0,null);
=====================================================
And while runing AppletFrame.java it is giving Error below
===============================
Exception in thread "main" java.lang.NullPointerException at java.applet.Applet.getDocumentBase(Applet.java:125)
at appletImageBook.appletImage.Standalone2.init(Standalone2.java:20) at appletImageBook.appletImage.AppletFrame.startApplet(AppletFrame.java: 38)
at appletImageBook.appletImage.AppletFrame.main(AppletFrame.java:99)
===============================
Any type of help will be fine for me
Thanks in advance

Answer 1

The only difference between an applet and an application should be the way they are started.
Instead of adding an applet to a frame, open a frame from the applet. Open the same frame from your application.
Or instead of a frame, use a (J)Panel. Add it directly to your applet, or add it to a new frame when you want to run it as an application.
In any case: separate the way the UI is created from the way the application is started.