Empty validatedBy in @Constraint

Question

I noticed that all built-in constraints have an empty value for the validatedBy parameter in @Constraint. i.e. @Constraint(validatedBy = {})

Answer 1

Those built-in are treated in special implementation-specific way and their validators are configured programmatically.

For Hibernate Validator it's done in ConstraintHelper.java. I think you can't achieve the same for your custom constraints.