Hi Markus,
if you build an MessageBodyWriter for e.g. JAXB, you have to check, if
the given class is annotated with JAXB annotations.
best regards
Stephan
Markus KARG schrieb:
> Dear JAX-RS Specification Authors,
>
> thank you so much for the invention of JAX-RS!
>
> Today I came across one thing that I think is not clear in the current
> draft of the API, and I want to propose an improvement.
>
> When implementing my own entity provider, I have to mark it as
> @Provider, and I have to implement MessageReader and / or
> MessageWriter. Both, MessageReader and MessageWriter are generic, so I
> can do "implements MessageReader<Product> to specify that my Provider
> actually is not "any" MessageReader but can only decode Product
> instances. So far, so good.
>
> But what I do not understand is: For what is the additional
> "isReadable" / "isWriteable" is needed? Actually, it is obvious that a
> MessageReader<Product> will only aswer "true" when it got passed a
> Product instance. In fact, I noticed that my MessageReader<Product>
> got asked for "isReadable(String)" at Runtime -- what makes no sense
> in my opinion.
>
> Is there something inside of isReadable that I did not see yet? For
> me, it looks like the "isReadable" / "isWriteable" methods can just be
> dropped in favour of the generic type provided at "implements
> MessageReader<T>". Another proposal could be to add the handled types
> at the @Provider annotation: @Provider(types = {T.class}) could be
> used as a nice replacement for implementing "isReadable" / "isWriteable".
>
> Thanks
> Markus