Ok. I can try to help: In this particular case, when you test you just set the field to what you want. In other cases where you actually want and need to test

Ok. I can try to help: In this particular case, when you test you just set the field to what you want. In other cases where you actually want and need to test that the annotations works at runtime you use a test container (Arquillian was the big thing for integration testing JavaEE last time it was relevant to me, and since we are talking enterprise Java there's a fair chance that Arquillian will still work and maybe even still be the most popular solution.)