NotNull « Map « JPA Q&A

1. "PropertyValueException: not-null property references a null or transient value" and "AssertionFailure: null id" if Child's field is @NotNull

I've set up a basic Parent/Child example with Seam 2 and Hibernate. I'm using Hibernate natively and I set up manual flushing. The example consists of 2 entities: Parent and Child, which ...

2. Confusion: @NotNull vs @Column(nullable = false)

  1. When they appear on a field/getter of an @Entity, what is the difference between them? (I persist the Entity through Hibernate).
  2. What framework and/or specification each one of them belongs to?
  3. @NotNull is ...