OSGi + Hibernate

Question

Instead of having database actions scattered in four (osgi) bundles, all doing there slightly different things. I want to create a (simple) OSGi bundle that is responsible for a

Answer 1

I'm going to recommend to stay away from buddy class loading as it's specific to Eclipse's Equinox implementation and, in my opinion, people get it to work but they don't understand why and everyone ends up as a buddy of everyone else. This stops you gaining a proper understanding of how OSGi classloading works and the patterns you need to use (composite class loaders, context class loading, OSGi services, ...) to work with it.

If your persistence bundle knows ahead-of-time what types it needs to persist, then the bundle can import all required packages (Require-Bundle is evil) that contain your domain classes.

Managing the context class loader (as in Roger's reply) can help with Hibernate, though I'd suggest using something like Spring dm to hide that behind an OSGi service.