@ResponseBody overwrites ContentType [SPR-6559]

[spring-projects-issues]

matthias boehmer opened SPR-6559 and commented

I have a controller with a method returning a simple string that contains a JSON object. The HttpServletRespose is avaiable as a method parameter. When I try to set the content type of the response to "application/json" is gets overwritten when I use @ResponseBody for mapping the return value to the response. It works well when I set the return type to void and write the response body directly into the HttpServletResponse using response.getWriter().write(jsonString).

Should not it be possible to set the content type, when I use @ResponseBody? This might be a bug, or at least it should be documented that @ResponseBody implicitly sets the content type.

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Issue Links:

• @ResponseBody doesn't obey CharacterEncodingFilter [SPR-6443] #11109 @ResponseBody doesn't obey CharacterEncodingFilter
• Explicitly set response Content-Type in @ResponseBody [SPR-6702] #11368 Explicitly set response Content-Type in @ResponseBody

[spring-projects-issues]

Arjen Poutsma commented

Currently, it's only possible to set the Content-Type by explicitly configuring the HttpMessageConverters for the AnnotationMethodHandlerAdapter, and then overriding the 'supportedMediaTypes' property. The first value of that property is the one used for writing. So in you case, that would mean something like this:

<beans>
  <bean class="org.springframework.http.converter.AbstractHttpMessageConverter">
    <property name="messageConverters">
         <bean class="org.springframework.http.converter.StringHttpMessageConverter">
            <property name="supportedMediaTypes" value="application/json"/>
         </bean>
      </property>
    </bean>

</beans>

This would set the String converter up for writing json.

In 3.1, we're going to allow the content-type to be set in the @ResponseBody, see #11368.

Also, I don't think it's wise to mix and math the use of HttpServletResponse and @ResponseBody. I recommend using either, but not both in the same method.