AnnotationMethodHandlerAdapter.handleResponseBody prioritizes messageConverter over MediaType [SPR-6877] #11543
Description
Ted Bergeron opened SPR-6877 and commented
The nested loop should be flip flopped. The current logic iterates over the message converters, then looks at the media types. For request header:
Accept application/json, text/javascript, */*
Which is sent via jQuery, this logic picks the first converter than can handle ```
*/*
private void handleResponseBody(Object returnValue, ServletWebRequest webRequest)
throws ServletException, IOException {
HttpInputMessage inputMessage = new ServletServerHttpRequest(webRequest.getRequest());
List<MediaType> acceptedMediaTypes = inputMessage.getHeaders().getAccept();
if (acceptedMediaTypes.isEmpty()) {
acceptedMediaTypes = Collections.singletonList(MediaType.ALL);
}
MediaType.sortBySpecificity(acceptedMediaTypes);
HttpOutputMessage outputMessage = new ServletServerHttpResponse(webRequest.getResponse());
Class<?> returnValueType = returnValue.getClass();
List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>();
if (messageConverters != null) {
for (HttpMessageConverter messageConverter : messageConverters) {
allSupportedMediaTypes.addAll(messageConverter.getSupportedMediaTypes());
for (MediaType acceptedMediaType : acceptedMediaTypes) {
if (messageConverter.canWrite(returnValueType, acceptedMediaType)) {
messageConverter.write(returnValue, acceptedMediaType, outputMessage);
this.responseArgumentUsed = true;
return;
}
}
}
}
throw new HttpMediaTypeNotAcceptableException(allSupportedMediaTypes);
}
In my case, I've registered the converters in the order matching the docs: http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/remoting.html#rest-message-conversion
<property name="messageConverters">
<list>
<bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
<bean class="org.springframework.http.converter.FormHttpMessageConverter"/>
<bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
<!--<bean class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter"/>-->
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/>
<bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter"/>
<!--<bean class="org.springframework.http.converter.BufferedImageHttpMessageConverter"/>-->
</list>
</property>
If I enable the xml converter, it tries to process my request, despite the json accept header. Nothing in the docs indicate that the ordering is very important, as I'd expect these to be mutually exclusive. If there is a specific ordering that should be used, please add that to the docs.
The only ordering I can see is the default in the code of:
private HttpMessageConverter<?>[] messageConverters =
new HttpMessageConverter[]{new ByteArrayHttpMessageConverter(), new StringHttpMessageConverter(),
new FormHttpMessageConverter(), new SourceHttpMessageConverter()};
---
**Affects:** 3.0.1
**Referenced from:** commits https://github.com/spring-projects/spring-framework/commit/3c8a47bd06023cf8eba681f56720c7dc5d532662, https://github.com/spring-projects/spring-framework/commit/62f9f477f5887c3c6237472d7d8db04510675ceb