Dear list,
I have prepared a (very) small open source project to provide domain entity mapping and association examples, together with a programmatic interface to reach outside the JPA 1.0 specifications. Currently it works with Hibernate, EclipseLink and (almost, but not quite) OpenJPA.
The intention is to provide a 'third' alternative to annotations and/or persistence.xml, where the entity classes contain only JPA annotations, with any remaining changes being made programmatically. The one-to-many example defines CascadeType.ALL, but actually requires a 'delete-orphans' extension for the tests to succeed.

I had better warn you all that I am a freelance consultant working in Italy and I use and will be using this work to sell both the advantages and disadvantages (but with solutions) of using JPA 1.0. to my clients.

Although the Hibernate part works, the programmatic interface is rather clumsy, having to practically recreate the HibernatePersistence class, yuk! Working in a vacuum (that's me and myself, and we don't always agree) does mean that I'm never quite sure that I've found a "good enough" solution. Any help would be greatly appreciated. I am working 'in collaboration with' two Java User Groups (Torino and Trento), but it's really me who wrote most of the code.

The open source project, called Spikes (guess why) can be downloaded via Subversion with the command:
svn checkout https://lab.jugtorino.it/svn/sandbox/spikes/trunk spikes
There is a Trac site at http://lab.jugtorino.it/trac/sandbox/wiki/Spikes, which I have converted to English in most places, and also an article (which started the project rolling) http://www.syger.it/Tutorials/JPA10Gotchas.html

Best regards
John Leach, Verona, Italy