Spring MVC - HttpMediaTypeNotAcceptableException

From: http://georgovassilis.blogspot.ca/2015/10/spring-mvc-rest-controller-says-406.html

You've got this Spring @RestController and mapped a URL that contains an email as part of the URL path. You cunningly worked around the dot truncation issue [1] and you are ready to roll. And suddenly, on some URLs, Spring will return a 406 [2] which says that the browser requested a certain content type and Spring can't serialize the response to that content type. The point is, you've been doing Spring applications for years and you did all the MVC declarations right and you included Jackson and basically you are stuck. Even worse, it will spit that error out only on some emails in the URL path, most notably those ending in a ".com" domain.

@RequestMapping(value = "/agenda/{email:.+}", method = RequestMethod.GET)
public List<AgendaEntryDTO> checkAgenda(@PathVariable("email") String email)

The issue [3] is quite tricky: the application server performs some content negotiation and convinces Spring that the browser requested a "application/x-msdownload" content, despite that occurring nowhere in the request the browser actually submitted.

The solution is to specify a content negotiation manager for the web application context:

<mvc:annotation-driven enable-matrix-variables="true"
    content-negotiation-manager="contentNegotiationManager" />
<bean id="contentNegotiationManager"
    class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
    <property name="defaultContentType" value="application/json" />
    <property name="favorPathExtension" value="false" />
    <property name="favorParameter" value="false" />
    <property name="parameterName" value="mediaType" />
    <property name="ignoreAcceptHeader" value="false" />
    <property name="useJaf" value="false" />
</bean>

Because this is the first google hit for "HttpMediaTypeNotAcceptableException" I like to add another problem that I've stumbled upon which resulted in HttpMediaTypeNotAcceptableException too.

In my case it was a controller that specified "produces", e.g.:

@RequestMapping(path = "/mypath/{filename}", method = RequestMethod.GET,
        produces = { MediaType.APPLICATION_XML_VALUE }

because I wanted to serve an XML file. At the same time I'm using a class with "@ControllerAdvice" to catch Exceptions, e.g. if the requested file wasn't found. The Exception handler was returning JSON so the client (angular) app could display the error message somewhere in the SPA.

Now the controller wanted to return XML but the Exception Handler was returning JSON so the HttpMediaTypeNotAcceptableException was raised. I solved this by adding JSON as possible "produces" value:

produces = { MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE}

Hope this helps somebody else. :-)

Please make sure that you have the following in your Spring xml file:

<context:annotation-config/> 

<bean id="jacksonMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"></bean>
 <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
  <list>
    <ref bean="jacksonMessageConverter"/>
  </list>
</property>
</bean>

and all items of your POJO should have getters/setters. Hope it helps

Make sure you add both Jackson jars to classpath:

• jackson-core-asl-x.jar
• jackson-mapper-asl-x.jar

Also, you must have the following in your Spring xml file:

<mvc:annotation-driven />