Using hibernate with generics

Question

I am having some trouble understanding how Hibernate deals with generics and was wondering the best way to accomplish my goal.

Given a simple generic entity:

Answer 1

What you're looking for is probably Hibernate's implicit polymorphism. There's also a little-known "any" relationship which gives complete flexibility, but it has its tradeoffs. You can also use an "any" in a many-to-any.

Edit: I've created a runnable example on Github based around your "Box" class and using an @Any mapping. You can browse it (or the Box class specifically) or check it out and run it with

git clone git://github.com/zzantozz/testbed tmp
cd tmp
mvn -q compile exec:java -Dexec.mainClass=rds.hibernate.AnyMapping -pl hibernate-any

Answer 2

I've already done that but with subclasses.

Your generic class must be abstract and subclasses must define the generic parameter