[bv-dev] Dependency between constraints and validators

Hello experts, one thing about BV I'm somewhat uncomfortable with is the (cyclic) dependency between constraint annotation types and their validators. This is, validators are referenced from constraints within the @Constraint meta-annotation, while constraint types are referenced by the type parameter in validator impl's. In particular this makes it impossible to clearly distinguish between the public API of a constraint library (the annotation types) and its implementation (the validators), e.g. by creating two distinct JARs. Therefore I'd personally prefer if there was only a reference from the validators to the constraints, but not the other way around. This of course raises the question how it would be determined which validators exist for a given constraint. One could think of using XML descriptors or some scanning-based approach. I guess from a technical POV this problem is somewhat related to what's to be done in CDI (finding bean implementations, processing qualifier annotations etc.). That said, I'd be very interested in your opinion on this topic. Do you think this is something we should address or do you think this sort of cycle is acceptable? Thanks, --Gunnar