title: JPA/Hibernate: how to automatically update fields on entity update
body: <p>I'm using Camel and JPA to persist entities to a Postgres DB. In each entity I have a field called "history" which contains all the old values of the given entity. I'm looking for a way to populate this field automatically before each update operations. 
  Surfing the web, I've found the JPA interceptors, but I've seen that they are used for auditing/logging purposes. Am I wrong? 
  What's the best way to do this?</p>