Problems with java.lang.NoClassDefFound error *solved*

Question

realising my stupidity I have solved the problem
I am quite new to java and I have been using the Java for Dummies book to help me to learn it. I decided to use the command line tools instead of an IDE and hadn't encountered any problems until recently. I took a break from learning Java after reaching the end of the book but have decided to come back to it. The problem now is that when I run my programs I get the following error:
Exception in thread "main" java.lang.NoClassDefFoundError: helloworld (wrong anme: HelloWorld)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at java.net.URLClassLoader.defineClass(Unknown Source)
     at java.net.URLClassLoader.access$000(Unknown Source)
     at java.net.URLClassLoader$1.run(Unknown Source)
     at java.security.AccessController.doPriviledged(Native Method)
     at java.net.URLClassLoader.findClass(Unknown Source)
     at sun.misc.Launcher$AppClassLoader.localClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClassInternal(Unknown Source)
This occurs from a simple hello world program:
class HelloWorld
   public static void main(String[] args)
      System.out.println("Hello, World!");
}I have no idea what the problem is, although by looking at similar threads it would appear that it may be something to do with the classpath variables however I do not know much about this as I followed a tutorial on the internet to set the classpath up.
Edited by: this_is_phil on Jun 19, 2008 11:11 AM

Answer 1

this_is_phil wrote:
Exception in thread "main" java.lang.NoClassDefFoundError: helloworld (wrong anme: HelloWorld)This part of the error message means you typed in "helloworld" but the class that java found was named HelloWorld. In Java, those are different - java is case sensitive. It will work if you enter HelloWorld.