jdk on macos x

if I try to use jde-wiz-implement-interface I get an error that jde  
can't find tools jar. I've read that I need to point jde at Classses/ 
classes.jar. How do I do that?

If I try to customize jde-jdk in gnu emacs it tells me the value as  
variable is nil. Is it supposed to be the name of the entry i the jdk  
registry? It also says "(mismatch)". The comments for jde-jdk  say  
that if I set jde-jdk to nil that it will read from JAVA_HOME and  
JAVA_VERSION environment variables, but if I set JAVA_HOME to a  
usable path, the path does not contain Classes/classes.jar.

If I set JAVA_HOME to

/System/Library/Frameworks/JavVM.framework/Versions/1.5.0

then there is no java in $JAVA_HOME/bin.

if I set it to

/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home

there is no Classes/classes.jar below the path.

Or is there another solution?