Re: [hibernate-dev] [Validator] Method level validation and cross parameter validator

Hi, a scripting-based approach as described by Hardy is also the first idea which would come to my mind. Maybe @ScriptAssert could even be re-used for this (I also thought about providing support for @ScriptAssert for property validation btw.). I'd like this idea as the contract is tightly integrated with the annotated method (e.g. it would be part of the method's JavaDoc etc.). As down-side there is the lack of type and refactoring safety. Another idea might be to support method-specific constraints similar to custom class-level constraints which would provide more type safety: public class BookingService { @ValidBooking public Reservation book(Date startDate, Date endDate) { //... } } @ValidBooking would be a custom annotation type: @Target({ METHOD }) @Retention(RUNTIME) @MethodConstraint(validatedBy = {ValidBookingValidator.class}) public @interface ValidBooking{} ValidBookingValidator would be a custom method constraint validator implementation with a specific isValid() method: public class ValidBookingValidator implements MethodValidator<ValidBooking> { public void initialize(ValidBooking constraintAnnotation) { } public boolean isValid(Date startDate, Date endDate, ConstraintValidatorContext constraintContext) { return startDate.before(endDate); } } Ideally this type would be generated by an annotation processor or similar. There might be an isValid() method for each different method signature annotated with @ValidBooking found by the generator. Gunnar 2011/2/18 Hardy Ferentschik <hibernate(a)ferentschik.de&gt;