[bv-dev] Triggering method validation

Hi experts, I'm in the middle of writing a proposal document for BVAL-241 (method validation), which I'm planning to put up for discussion within the next days. One item for which I'd like to gather some feedback beforehand is how to trigger method validation. I think we all agree that BV itself should only provide the API and meta-model for method validation, but it shouldn't actually trigger a validation of method level constraints. Instead this should be task of technologies integrating the method validation feature to decide whether a validation is needed or not and if so delegate that validation to BV. The following options were mentioned at some time: #1 Use @Valid This would be semantically wrong IMO. @Valid is only a marker for cascaded validation, but it shouldn't cause a validation itself. #2 Define an annotation such as @javax.validation.ValidateGroups within BV @ValidateGroups({Group1.class, Group2.class}) public class OrderService { @NotNull public Order placeOrder((a)NotNull(groups=Group1.class) @Size(min=3, max=20) String customerCode, @NotNull Item item, @Min(1) int quantity) { //... } } This annotation could be discovered by interceptors/proxies etc. which then would trigger a validation of the method constraints. The method could be defined on a class level as well as on method level (with the latter having precedence in case of conflicts). We could surely define such an annotation and specify it semantics, but I'm unsure how that would actually work out with technologies using that feature. Taking CDI for example, AFAIK the annotation would have to be annotated with the @InterceptorBinding meta annotation. I don't know whether/how it would be possible that we define the "basic" annotation, while integrators "enrich" it with the meta data they require. #3 Don't define anything related in BV, leave that completely to integrators CDI could define a proper interceptor binding annotation, others could use some XML based configuration etc. Personally I think we could go for #2 and define an annotation to be used by integrators (e.g. by checking for the annotation, Spring might define a related point cut etc.). We would recommend to trigger validation based on this annotation where possible and hopeful would cover most cases that way. Integrators would still be free to define their own means of triggering a validation if required. Any thoughts? Are there any other alternatives? --Gunnar