Compiles but java.lang.NoClassDefFoundError when I try to run it

[manavo11]

When I compile my code, I do this :

C:\Program Files\Java\jdk1.5.0\bin>javac c:\java\hello.java

But when I go to run the class file I get the following error :

C:\Program Files\Java\jdk1.5.0\bin>java c:\java\hello
Exception in thread "main" java.lang.NoClassDefFoundError: c:\java\hello

The code I have made (very advanced :D ):

class Hello {
public static void main(String [] args) {
System.out.println("Hello world");
}
}

Any ideas?

Thanks :)

[brown monkey]

Originally posted by manavo11
The code I have made (very advanced :D ):

:D Just got mine running.

I suggest you put the directory of your java exes to your Path Environment Variables. By this, you can javac, java on all directories you are in.

edit: Or just set your classpath to c:\java and simple java Hello.

[CornedBee]

Usage:
java [options] classname
"c:\java\hello" is not the classname, it's the path of your class file with the .class stripped. That's different, very different.
Correct would be
java -classpath="%CLASSPATH%;c:\java\" hello

[manavo11]

And %CLASSPATH% being the enviromental variable? How do I set that? I create it myself?

[Dillinger4]

I dont know what os you are running but since i am running win98 i just open the System Configuration Editor and change the AutoExec.bat file.

[brown monkey]

Originally posted by manavo11
And %CLASSPATH% being the enviromental variable? How do I set that? I create it myself?

I'm guessing you are using 2000, which I don't know. Hehehe. This is what I did in my XP time machine.

- Right click My Computer then Properties
- Advanced Tab
- Environment Variables
- System Variables then New
- Variable name: classpath, Variable value: c:\java;some_directory...
- Ok, Ok then Ok. :bigyello:

Hope this helps. If not, sorry.

[manavo11]

I have XP so I'll try what you said BM :) Thanks :)

[manavo11]

Originally posted by brown monkey
I'm guessing you are using 2000, which I don't know. Hehehe. This is what I did in my XP time machine.

- Right click My Computer then Properties
- Advanced Tab
- Environment Variables
- System Variables then New
- Variable name: classpath, Variable value: c:\java;some_directory...
- Ok, Ok then Ok. :bigyello:

Hope this helps. If not, sorry.

Hmmm, is version 5 needed?

Registry key 'Software\JavaSoft\Java Runtime Environment\CurrentVersion'
has value '1.4', but '1.5' is required.
Error: could not find java.dll
Error: could not find Java 2 Runtime Environment.

[brown monkey]

I don't know if this helps but did you install the Java Runtime? You have the sdk 1.5 and you are using the Runtime 1.4. It requires the 1.5 Runtime, I guess.

[manavo11]

Actually I don't know what I am doing :( I had installed version 5, then my teacher gave me 1.4.2 to use so I don't even know what I have anymore :(

[System_Error]

What is your classpath environment variable set to? If you have already set it, and you think it's correct but it's still not running the program, you can usually add .;%classpath%.; at the begining of your classpath and it will work.

[manavo11]

Thanks :) I'll try it when I get home :)