Add content-negotiation to RequestBody and ResponseBody processing [SPR-6993]

[spring-projects-issues]

Paul Austin opened SPR-6993 and commented

At the moment the AnnotationMethodHandlerAdaptor only uses a simple approach to content negotiation for RequestBody and ResponseBody parameters using the Accept and Content-type headers.

It would be useful if additional content negotiation, such as using file name extensions, request parameter and a default media type were also provided. This is similar to the approach provided by the ContentNegotiatingViewResolver for views.

I have implemented an example implementation if you'd like to use that as a basis for the implementation.

Look at the ServletHandlerMethodInvoker.handleResponseBodyMethod and the ServletHandlerMethodInvoker.resolveRequestBody. You'll see it uses a MediaTypeUtils class to get all the possible accepted media types.

The MediaTypeUtils uses the mediaTypeOrder field to decide which order the content negotiation should be performed in. This gives the developer the option to decide which types of content negotiation can be performed and the precedence order of these. The important thing to note is that all media types from all the selected sources are added so that there is fall back if one of the options is not supported by the different message converters.

---

Affects: 3.0.1

Attachments:

• AnnotationMethodHandlerAdapter.java (47.27 kB)
• ContentNegotatingResponseBody.java (5.91 kB)
• ContentNegotatingResponseBody.java (5.86 kB)
• MediaTypeUtil.java (4.29 kB)

Issue Links:

• @RequestMapping should support accept header and url extension [SPR-6497] #11163 @RequestMapping should support accept header and url extension ("duplicates")
• Content negotiation improvements [SPR-8410] #13057 Content negotiation improvements ("is superseded by")

9 votes, 7 watchers

[spring-projects-issues]

Ted Young commented

I too was thwarted by the inability to configure ResponseBody to use file extensions. I have uploaded a Spring aspect (ContentNegotatingResponseBody) that adds file extension detection to ResponseBody. It is configured much like ContentNegotiatingViewResolver (map extensions to media types). See the JavaDoc. It wouldn't be difficult to extend this further with support for parameters. I hope this can help until a fix is released.

[spring-projects-issues]

Ted Young commented

A Spring aspect that alters the interpretation of ResponseBody, allowing it to take into account url file extensions during content negotiation.

[spring-projects-issues]

Ted Young commented

For what it is worth, I wrote an article about how to accomplish this behavior using ContentNegotatingResponseBody: http://tedyoung.me/2011/07/28/spring-mvc-responsebody/. I hope this helps.

[spring-projects-issues]

Rossen Stoyanchev commented

There have been quite a few changes in the area of content negotiation with the introduction of the produces and consumes @RequestMapping conditions in Spring 3.1 as well as a new RequestMappingHandlerAdapter for processing requests with annotated controllers. There is no support yet for what is requested here yet but it is something that's planned. The umbrella issue for that is #13057.

[spring-projects-issues]

Rossen Stoyanchev commented

This is now supported. To configure, declare a ContentNegotiationManager bean and use it in turn to configure RequestMappingHandlerMapping, RequestMappingHandlerAdapter and ExceptionHandlerExceptionResolver.