What Java ORM library implementing JPA that match following criteria would you recommend and why ?
- free & open source
- alive (at least bug fixes and a mailing list)
- with good documentation
- simple (simpler than hibernate)
I need to select a simple ORM tool that can be set up in minutes, without too much configuration and easy to understand, for setting simple CRUD DAOs. A query builder will be an interesting plus. Later I can have to move to Hibernate, that's why being JPA compliant is a must.
I have found some candidates on the web, but not so much feedback, so I will gladly take your advices on the topic.
----- EDIT ---------
I have been successfully testing ebean/avaje with a small test cases. Any one has a feedback on using these tools in production ?