[bv-dev] Bean Validation and JAX-RS: conversion too?

Hello Volunteers, I've been viewing Emmanuel's videos about BV 1.1 and whenever he talks about Bean Validation and JAX-RS, such as this @Path("/user") class UserResource { @Post @Consumes("application/x-www-form-urlencoded") public void register( @NotEmpty @FormParam("firstname") String firstname, @NotEmpty @FormParam("lastname") String lastname, @NotNull @Email @FormParam("email") String email) { ... } } I have to ask myself, isn't this missing something? What about conversion? Before Bean Validation, JSF brought type conversion *and* validation to the table. Now that Bean Validation provides the validation part for all of JavaEE, isn't it time we think about the other part: type conversion? JSF has an elaborate conversion system with by-type conventions and also the ability to manually declare that specific converters should be used for specific values. It's not a far cry to realize that we don't need to limit ourselves to "String" for these arguments and there is a lot we could do to enable arbitrary types and have Bean Validation handle the conversion on the way in. JAX-RS also has the javax.ws.rs.ext.ParamConverter facility, which solves the conversion problem in a JAX-RS specific way. Here we have two specs that do conversion. I think it might be useful to realize that type conversion is really just the first part of validation, and therefore falls under the responsibility of Bean Validation. Is this worth pursuing? Ed --