Runtime JDBC NoClassDefFoundError

[sjpatrick]

At my wits' end here...

I'm certain six ways from Sunday that my classpath is correct, so please resist telling me that's my problem.

I started by getting this error using MySql Connector, and have progressed to even trying a brand new install of postgres, but continue to get this selfsame error:

Exception in thread "main" java.loang.NoClassDefFoundError: HelloJava

Only at runtime; compiles clean as a whistle.

Anybody got a silver bullet?

 

[sedj]

You're not going to like it ...

Its your CLASSPATH . 100% .

There are three possibilities that I know of for causing a NoClassDefFoundError :

1) The class is not on the CLASSPATH

2) There is a naming conflict on the CLASSPATH - ie two classes named "Whatever.class" exist - and the ClassLoader barfs trying to load them

3) A native/JNI based resource that your class, or another class used by your class, is required, but that native resource is not in the PATH, or LD_LIBRARY_PATH .

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[LFI]

Just because your *.java code is in the path, doesn't mean your final *.class file is. I was once using some software to compile my code. It did the job, but I couldn't control where it was putting the *.class file. I'd have to go get it and move it everytime I used this! Needless to say, I don't use that software for compiling code anymore!

Anyway, double-check that your *.class file is where it needs to be.

I'm not exactly telling you to check your classpath!

'hope that helps.

--Dave

 

[sjpatrick]

Okay, sedj.

You win.

I went back to a dumb hello program and I get the same error.

I'm running jdk5_02 on linux; any clues as to what I'm forgetting to put in my classpath?

 

[sedj]

Say your Hello.class is in /usr/local/java , then you need to set your CLASSPATH thus :

export CLASSPATH=$CLASSPATH:/usr/local/java

Then it should be fine.

Don't forget that many Linux distros come with GNU's Java installed - not Sun's - so you should check that the Sun version of the JRE is being picked up - type "java -version" to determine this.



--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[sjpatrick]

I am officially a moron.

The "silver bullet" is as such:

Separate the assorted values in your classpath statement with COLONS, not semicolons!

(blushing and how...)

Thanks for the help, sedj; I would never have found this if you hadn't forced me to look harder.

 

[sedj]

lol, too much DOS/Win32 time sounds like !

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[sjpatrick]

Unfortunately.

Went all the way back to mysql jdbc and it works like a charm.