MappingJacksonHttpMessageConverter default media type should include *+json [SPR-7905]

[spring-projects-issues]

David Melia opened SPR-7905 and commented

Hi,

Currently in my REST service which supports both XML and JSON I am using the accept header so the same URL can provide different end points which will provide versioning. So my accept header is of the format

Accept=application/appname-v1+xml or Accept=application/appname-v1+json

which can route through the the v1 (version1) version of my REST method. The above is fine for XML as AbstractXmlHttpMessageConverter (subclass of Jaxb2RootElementHttpMessageConverter) registers the media type

new MediaType("application", "*+xml")
``` so this wildcard satisfies my accept header no problem.

However, for JSON, MappingJacksonHttpMessageConverter only registers ```
new MediaType("application", "json", DEFAULT_CHARSET)
``` which means I cannot use <mvc:annotation-driven/> out of the box :-(

Any chance we could have MappingJacksonHttpMessageConverter also registering ```
new MediaType("application", "*+json", DEFAULT_CHARSET)

This would result in a lot less configuration as I have to do the following in place of mvc:annotation-driven/

<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
   <property name="messageConverters" ref="messageConverters" />
</bean>
<!-- Message converters -->
<util:list id="messageConverters">
   <bean class="org.springframework.http.converter.StringHttpMessageConverter" />   
    <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
       <property name="supportedMediaTypes">
          <list>
              <bean class="org.springframework.http.MediaType">
                 <constructor-arg value="application" />
                 <constructor-arg value="json" />
               </bean> 
             <bean class="org.springframework.http.MediaType">
                <constructor-arg value="application" />
                <constructor-arg value="*+json" />
             </bean>
          </list>
       </property>
    </bean>
    <bean class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter" />
   <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter" />
   <bean class="org.springframework.http.converter.FormHttpMessageConverter" />
   <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter" />
</util:list>	

Thanks

---

Affects: 3.0.5

Issue Links:

• MediaType's include method does not check for generalization when using a format extension/suffix [SPR-9635] #14269 MediaType's include method does not check for generalization when using a format extension/suffix ("is duplicated by")
• ContentNegotiatingViewResolver does not support wildcards in contentType [SPR-9807] #14440 ContentNegotiatingViewResolver does not support wildcards in contentType

Referenced from: commits 8270d82, e16c403, 4f114a6

4 votes, 8 watchers

[spring-projects-issues]

David commented

This is affecting me as well.

Unfortunately, I can't use the suggested workaround because removing <annotation-driven> breaks other things:

Ambiguous handler methods mapped for HTTP path '/projects':
{ public org.springframework.http.ResponseEntity ...ProjectController.getProjectsCollectionXML(javax.servlet.http.HttpServletRequest),
public org.springframework.http.ResponseEntity ...ProjectController.getProjectsXML(javax.servlet.http.HttpServletRequest)}.

If you intend to handle the same path in multiple methods, then factor them out into a dedicated handler
class with that path mapped at the type level!

(in my case, I have multiple methods in my controller for the same path but different produces= values,
i.e. produces="application/json" vs. produces="application/vnd.sas.sometype+json") and tracking those errors down turns into a rat hole.

If I add the MappingJacksonHttpMessageConverter bean
above, Spring still instantiates a default MappingJacksonHttpMessageConverter instance elsewhere (with just [application/json;charset=UTF-8] ) in addition to the above custom bean with three media types, and then
Spring passes the default instance to my controller, not the one I configured.

I tried to add a MappingJacksonHttpMessageConverter @Autowire property to my controller but that also fails, as there is not yet a MappingJacksonHttpMessageConverter instance when my controller is loaded/configured
unless I explicitly list that bean as above, but even then, my setter is called with my configured bean,
but the default one is still used when Spring tries to match message converters.

Thus, I don't see how to work around this in a maintainable way. I think this should be changed from Minor to Normal, or some other workaround provided.

[spring-projects-issues]

David Melia commented

Hi,

Just a reply to David in that using Spring 3.1 you can still use annotation driven as such:

<mvc:annotation-driven >
   <mvc:message-converters register-defaults="false">
        <bean class="org.springframework.http.converter.StringHttpMessageConverter" />
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
           <property name="supportedMediaTypes">
              <list>
            <bean class="org.springframework.http.MediaType">
                 <constructor-arg value="application" />
                 <constructor-arg value="json" />
            </bean>
                  <bean class="org.springframework.http.MediaType">
                                         <constructor-arg value="application" />
                       <constructor-arg value="*+json" />
                </bean>
              </list>
           </property>
        </bean>
        <bean class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter" />
        <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter" />
        <bean class="org.springframework.http.converter.FormHttpMessageConverter" />
        <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter" />
   </mvc:message-converters>   	
</mvc:annotation-driven>   

however I stand by my original request as the above is verbose.

Thanks

[spring-projects-issues]

David commented

Excellent - this works!

Since we'll have multiple web apps/servlets needing to do this,
I've created our own MappingJacksonHttpMessageConverterWithWildcard that extends MappingJacksonHttpMessageConverter
and sets the supported media types (application/json, text/json, application+json) in its constructor
and thus each web app can use just

<bean class="com.sas.commons.rest.spring.json.MappingJacksonHttpMessageConverterWithWildcard"/>

instead of the MappingJacksonHttpMessageConverter bean config above, and thereby reduce maintenance and clutter.

Thanks, @DavidMelia - I would never have figured this out!

[spring-projects-issues]

Tim Meighen commented

I have added Pull Request #130 for this.

[spring-projects-issues]

Rossen Stoyanchev commented

#130

[spring-projects-issues]

Felix Barnsteiner commented

<mvc:annotation-driven>
    <mvc:message-converters>
        <bean id="jacksonHttpMessageConverter"
              class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
            <property name="supportedMediaTypes">
                <list>
                    <value>application/json</value>
                    <value>application/*+json</value>
                </list>
            </property>
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>

Works as well and is less verbose.
See also https://jira.springsource.org/browse/SPR-7504
But it would indeed be nice, if this was the default behaviour.