Re: [hibernate-dev] Feedback on Bean Validation JAX-RS integration

Hi, I agree with Hardy - this looks very interesting. I think there is to some degree an overlap with method validation as possibly part of BV 1.1. I don't know about the timeline for the JAX-RS proposal, but it might make sense that they base their work on BV 1.1. Some minor remarks: * In listing 2 setEmail() instead of a getter is annotated. I'm not sure whether this is intentionally, otherwise it would make sense to use getters as in BV. * "All constraint annotations used in resource classes are validated in the Default group". Maybe this could be configured using an annotation on the resource or similar: @Path("/") @ValidationGroups(SomeGroup.class) class MyResourceClass { ... } * "The order in which validations are checked is as follows: constraint validations on fields and properties are checked first, on resource classes are checked next" I don't think we could currently ensure such an order in HV but I guess it could be implemented. The question is whether this is really required. * "If the getUser() method in [the implementing class] MyResourceClass is decorated with any annotation ... all of the annotations in the [implemented] interface will be ignored. I think this might require some more consideration. In HV we decided against such an approach, as preconditions shouldn't be strengthened in sub-types in order to obey to the Liskov substitution principle [1]. Instead of the very conservative approach currently taken by HV (not allowing parameter constraints for one method in several places in a hierarchy) one could also OR-join the constraints from a method hierarchy causing the "weakest" contract in the hierarchy becoming effective. That's the way taken by most DbC frameworks. * "... including javax.validation.ConstraintValidationException" I think ConstraintViolationException is meant. * I'm not completely sure about the client API part. Maybe clients could just validate standard beans populated with values retrieved via JAX-RS? Implementing annotation interfaces with classes seems somewhat uncommon. As Hardy said it might make sense to follow the ConstraintDef approach from HV. If the programmatic API is added to BV 1.1 the JAX-RS team might benefit from this of course. I'm also CC'ing Jozef, lead of the Seam REST module which provides an integration with Bean Validation [2]. --Gunnar [1] http://docs.jboss.org/hibernate/stable/validator/reference/en-US/html_sin... [2] http://docs.jboss.org/seam/3/rest/latest/reference/en-US/html/rest.valida... 2011/6/30 Hardy Ferentschik <hardy(a)hibernate.org&gt;: