[CALUG] jikes Java complier can't find java.lang

[Eldon Ziegler]

I downloaded a java app that uses the jikes compiler but running it
results in 

Found 1 system error:

*** Semantic Error: You need to modify your classpath, sourcepath,
bootclasspath, and/or extdirs setup. Jikes could not find package
"java.lang" in: 
                .
                .

make: *** [vncviewer.jar] Error 1

What should classpath, etc be set to?

Thanks
Eldon