How to refresh JPA entities when backend database changes asynchronously?

Question

I have a PostgreSQL 8.4 database with some tables and views which are essentially joins on some of the tables. I used NetBeans 7.2 (as described here) to create REST based

Answer 1

Just a thought, but how do you receive your EntityManager/Session/whatever?

If you queried the entity in one session, it will be detached in the next one and you will have to merge it back into the persistence context to get it managed again.

Trying to work with detached entities may result in those not-managed exceptions, you should re-query the entity or you could try it with merge (or similar methods).