File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Applets and the fly likes What is Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Applets
Bookmark "What is "java.lang.ClassFormatError: bad magic number"?" Watch "What is "java.lang.ClassFormatError: bad magic number"?" New topic

What is "java.lang.ClassFormatError: bad magic number"?

Gary Bryan

Joined: Sep 16, 2000
Posts: 9
I have written an applet, and when I try to load it on the Internet, i get an error like the above. It works fine locally, it's just on the Internet it doesn't work. The applet fails to load because of this.
Gary Bryan

--<BR>Gary Bryan<BR>
Noah Carroll
Ranch Hand

Joined: Sep 20, 2000
Posts: 96
I believe you get that error when the class file cannot be found. Make sure you have the correct path to it and remember that capitalization does count for the applet name.
[ March 31, 2008: Message edited by: Noah Carroll ]
Brooks Duncan

Joined: Oct 16, 2000
Posts: 5
I have gotten that error when I have somehow gotten a corrupt .class file. Usually it happens when I forget to put the jar name when I try to jar something, and it ends up screwing up all the class files in the folder.
Try recompiling your .java file(s) and see if that helps.
I agree. Here's the link:
subject: What is "java.lang.ClassFormatError: bad magic number"?
It's not a secret anymore!