Resteasy default implementation of org.jboss.resteasy.spi.validation.GeneralValidator handles all javax.validation.ValidationException the same way wrapping them in a org.jboss.resteasy.api.validation.ResteasyViolationException which is a subclass of javax.validation.ConstraintViolationException.

So it is not possible to handle any other javax.validation.ValidationException subtypes such as javax.validation.ConstraintDeclarationException in a dedicated ExceptionMapper<ConstraintDeclarationException> since the exception is not correctly thrown.