Datanucleus enhancer & javaw: "parameter is incorrect"

Question

I work on Windows XP using eclipse and datanucleus enhancer for the gwt + gae application. When I start the enhancer, I get an error message:

Error Thu Oct 21 16:33:57 CDT 2010 Cannot run program "C:\Program Files\Java\jdk1.6.0_18\bin\javaw.exe" (in directory "C:\ag\dev"): CreateProcess error=87, The parameter is incorrect java.io.IOException: Cannot run program "C:\Program Files\Java\jdk1.6.0_18\bin\javaw.exe" (in directory "C:\ag\dev"): CreateProcess error=87, The parameter is incorrect at java.lang.ProcessBuilder.start(Unknown Source) at com.google.gdt.eclipse.core.ProcessUtilities.launchProcessAndActivateOnError(ProcessUtilities.java:213) at com.google.appengine.eclipse.core.orm.enhancement.EnhancerJob.runInWorkspace(EnhancerJob.java:154) at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) Caused by: java.io.IOException: CreateProcess error=87, The parameter is incorrect at java.lang.ProcessImpl.create(Native Method) at java.lang.ProcessImpl.<init>(Unknown Source) at java.lang.ProcessImpl.start(Unknown Source) ... 5 more 

I had this problem before, and this was due to the long path of the class. I just spent an hour and a half reducing my class, moving libraries and even moving the eclipse installation, but no luck.

Any ideas on where I should start looking for an answer? The error message does not contain any information about which directory it is in or something else. It's disgusting! Is it possible to make javaw's output more verbose? Is there a way around this class size error?

Answer 1

Yeah!

In the properties of the project> Google> App Engine> ORM, I found that all my classes were extended, which led to a command line that was too long - apparently, it has nothing to do with the class path. I just configured this property page only to improve a subset of my classes (only 5% need improvement), and now it not only works again, but the build process is WAY FASTER!