Spring 3 REST with XML gives "406 Not Acceptable"

Question

I'm trying to implement REST Remoting using Spring 3 but I can't get through "406 Not Acceptable" error... I try to remote 1 service that is returning an application/xml content. Everytime I send a request with "Accept=application/xml", I get 406 error. Everytime I send it with some different "Accept" header, I get 404 (and handleNoSuchRequestHandlingMethod exception). The service itself is invoked as I can see it in the logs. What I've also spotted is that during servlet initialisation I get the following error, although I'm not sure if it's a problem:

Did not find any ViewResolvers to delegate to; please configure them using the 'viewResolvers' property on the ContentNegotiatingViewResolver

I've tried many different configurations but without success. Maybe you can spot some error in my implementation?

extService-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:util="http://www.springframework.org/schema/util"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:task="http://www.springframework.org/schema/task" xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:oxm="http://www.springframework.org/schema/oxm" xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd
                        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
                        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
                        http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd
                        http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-3.0.xsd
                        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <context:component-scan base-package="ch.epimmo.immogreen.backend.mvc" />

    <mvc:annotation-driven />

    <oxm:jaxb2-marshaller id="jaxbMarshaller">
        <oxm:class-to-be-bound name="ch.epimmo.immogreen.common.dto.ExpertDto" />
    </oxm:jaxb2-marshaller>


    <bean
        class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver"
        p:order="#{T(org.springframework.core.Ordered).HIGHEST_PRECEDENCE}">
        <property name="defaultContentType" value="text/html" />
        <!-- <property name="ignoreAcceptHeader" value="true" /> -->
        <property name="favorPathExtension" value="true" />
        <property name="mediaTypes">
            <map>
                <entry key="xml" value="application/xml" />
            </map>
        </property>
        <property name="defaultViews">
            <list>
                <bean class="org.springframework.web.servlet.view.xml.MarshallingView">
                    <property name="marshaller" ref="jaxbMarshaller" />
                </bean>
            </list>
        </property>
    </bean>
</beans>

Controller

@Controller
@RequestMapping( { "extService" })
public class ExtServiceController {

    protected final static Logger LOGGER = Logger.getLogger(ExtServiceController.class);

    @Autowired
    private UserManagementService userManagementService;    

    // @RequestMapping(value = "/experts", method = RequestMethod.GET, headers = { "Accept=*/*" })
    // @RequestMapping(value = "experts", method = RequestMethod.GET)
    @RequestMapping(value = "experts", method = RequestMethod.GET, headers = { "Accept=application/xml, text/xml" })
    public @ResponseBody
    ExpertDto getExperts() {            
              return new ExpertDto();
    }
}

Test

DefaultHttpClient httpClient = new DefaultHttpClient();

String expertsUrl = "http://localhost:8080/extService/experts";

HttpGet getRequest = new HttpGet(expertsUrl);
getRequest.setHeader(new BasicHeader("Accept", "application/xml"));
// getRequest.setHeader(new BasicHeader("Accept", "text/html"));
// getRequest.setHeader(new BasicHeader("Accept", "*/*"));

HttpResponse response = httpClient.execute(getRequest);
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();

Answer 1

Consider using the following approach instead of @ResponseBody

@RequestMapping(value = "experts", method = RequestMethod.GET)
public @ResponseBody
void getExperts(org.springframework.ui.Model model) {            
      model.addAttribute(new ExpertDto());
}

The "Did not find any ViewResolvers to delegate to..." is just a warning, you can ignore it.