Maybe section 3.8 should remove step 4 then? If there is no @Produces,
and no response content-type header and no Accept header, IMO, a 406
should be returned.
Marc Hadley wrote:
> What does the request accept header look like, I'm guessing its not very
> specific ? If it has anything other than text/yaml then the runtime
> should select the ToStringProvider, for text/yaml it should select the
> YamlProvider.
>
> Requiring the content-type to be set means you have to edit all of the
> resource classes to add support for a new media type, currently you can
> just drop in a new MBW. I think the issue you bring up only occurs when
> the client doesn't include a specific accept header with a request.
>
> Marc.
>
> On Feb 7, 2009, at 12:10 AM, Bill Burke wrote:
>
>> I've recently run into problems with the current rules on "Determining
>> the MediaType of Responses" in Section 3.8.
>>
>> Specifically, if there is no @Produces and no Content-Type header set,
>> the the JAX-RS provider creates a set of possible media types from
>> MessageBodyWriters that "support" the entity type.
>>
>> *THIS IS BAD*
>>
>> Why? Adding a new provider can drastically change the behavior or
>> your application.
>>
>> I have a writer that just does object.toString() for all text/*:
>>
>> @Produces("text/*")
>> public class ToStringProvider implements MessageBodyWriter
>> {
>> boolean isWritable(...)
>> {
>> return true;
>> }
>> }
>>
>> I come along later in the app development cycle and introduce a
>> provider that can generate YAML from any Java Object:
>>
>> @Produces({"text/yaml", "text/x-yaml", "application/x-yaml"})
>> public class YamlProvider implements MessageBodyWriter
>> {
>> boolean isWritable(...)
>> {
>> return true;
>> }
>> }
>>
>> Now, instead of writing text/plain, I'm not outputting YAML. A
>> seemingly innocent introduction of a provider change the whole
>> behavior of the application (unknowingly).
>>
>> --
>> Bill Burke
>> JBoss, a division of Red Hat
>> http://bill.burkecentral.com
>>
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>>
>
> ---
> Marc Hadley <marc.hadley at sun.com>
> CTO Office, Sun Microsystems.
>
>
>
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>
--
Bill Burke
JBoss, a division of Red Hat
http://bill.burkecentral.com