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Steve Wang

Joined: Jun 27, 2003
Posts: 18
I downloaded JDK 1.4.1_05 and tried to write a summy class to test it. This following is my code and compilation is OK. When I tried to run it like "java A". I got this error:
Exception in thread "main" java.lang.NoClassDefFoundError: A
Do not understand what this means and how to fix it.
Here is the simple code:

Can anyone there help this out please? Thanks.
Marie Mazerolle
Ranch Hand

Joined: Oct 01, 2002
Posts: 81
From Sun's "First cup of Java" tutorial:
Error Explanation
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorldApp
If you receive this error, java cannot find your bytecode file, HelloWorldApp.class.
One of the places java tries to find your bytecode file is your current directory. So, if your bytecode file is in C:\java, you should change your current directory to that. To change your directory, type the following command at the prompt and press Enter:
cd c:\java
The prompt should change to C:\java>. If you enter dir at the prompt, you should see your .java and .class files. Now enter java HelloWorldApp again.
If you still have problems, you might have to change your CLASSPATH variable. To see if this is necessary, try "clobbering" the classpath with the following command:
Now enter java HelloWorldApp again. If the program works now, you'll have to change your CLASSPATH variable. For more information, consult the section 5. Update the PATH variable in the installation instructions.
Hope this helps!
It is sorta covered in the JavaRanch Style Guide.
subject: NoClassDefFoundError
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