[stephen]

Yeah, I can't believe JPA/most ORMs don't maintain both sides of a relationship. That sort of stuff should just work.

I implemented my own ORM (http://joist.ws) a few years ago to solve this and my other JPA/Hibernate annoyances. It works really well, modulo the fact that I suck at docs/promotion/etc. so it doesn't have many users (working on that).

Also note that, specific for the playframework, someone seems to have implemented the necessary magic in a plugin:

http://www.playframework.org/modules/associations

Which is nifty, other than I'm slightly wary of the "magic that happens via runtime class rewriting" that seems to be Play's standard way of doing things. The results are admittedly impressive, but it seems like you're coupling yourself to yet-another-runtime-environment/container for things to work right.