there seems to be a problem with EJB 3.0 generation and JDK 6, at last on my machine under Windows Vista.
If I set Jdeveloper (TP4 oder 10.1.3.4) to JDK 6 (in jdev.conf) and generate "Entities from Tables" for tables with combined keys, I'm getting an entity class and a primary key class, but both have no properties or fields or methods.
The generation process ends without saying "Finished generating CMP entity beans".
If I switch back (both in TP4 and 10.1.3.4) to the original JDK, it works fine.
If I generate "Entity from Tables" for a simple table with only one key, it works with both JDKs fine.
If I start TP4 with JDK 6 and switch only the project to JDK 5, it works fine (for both simple and combined keys) , too.
Starting Jdeveloper from a DOS Box reveals no error messages in the not working cases.
Although it's ok for me, to run only IDE with JDK 6 for better display experience, the reason for this behaviour would be interesting.
By "combined keys" - do you mean a composite primary key (e.g. a primary key comprised of multiple columns)?
I can confirm the same behaviour using the following:
JDK 1.6.0_10 (release candidate)
Oracle Database 11g
JDeveloper 11g (the build made available for Ace Directors to test).
So, I'll +1 that it's a bug.