Numerous warnings abound in ConstraintViolation due to the fact that ConstraintValidationListener must be used as a raw type. Further the GroupValidationContext must be cast to a BeanValidationContext so that the listener reference can be reset, which doesn't feel optimal either. The attached patch:
- Modifies GroupValidationContext<T> such that, rather than extending ValidationContext<T> where T extends ValidationListener, it instead expressly implements ValidationContext<ConstraintValidationListener<T>> (T is now effectively the same type variable as ConstraintValidationListener<T>). Now GroupValidationContext.getListener() expressly returns a ConstraintValidationListener.
- Adds state management for @ReportAsSingleViolation composed constraints to ConstraintValidationListener so that the original listener instance can be used throughout.
- The reportAsSingle execution path bails as soon as it is known that a composing constraint has failed.