Question

I’m trying to set up a spring 3.1 mvc webservice that will return xml. I have a method which returns the xml as a string already called getxmlforparam().
Below is a snippet of the code I have so far which always returns the correct content but with the wrong content-type = text/html.

Is there a way of setting the content type other than with the RequestMapping produces and response.addHeader techniques that I have tried below?

@Service
@RequestMapping(value="endpointname")
public class XmlRetriever {

  //set up variables here
  @RequestMapping(method = RequestMethod.GET, produces = "application/xml")
  @ResponseBody
  public String getXml(
    @RequestParam(value = "param1") final String param1,
    /*final HttpServletResponse response*/){

    String result = null;
    result = getxmlforparam(param1);

    /*response.addHeader("Content-Type", "application/xml");*/
    return result;
}

Thanks.

EDIT:
solution by writing straight to the response object per MikeN’s suggestion below:

@Service
@RequestMapping(value="endpointname")
public class XmlRetriever {

  //set up variables here
  @RequestMapping(method = RequestMethod.GET, produces = "application/xml")
  @ResponseBody
  public String getXml(
    @RequestParam(value = "param1") final String param1,
    final HttpServletResponse response){

    String result = null;
    result = getxmlforparam(param1);

    response.setContentType("application/xml");
    try{
     PrintWriter writer = response.getWriter();
     writer.write(result);
    }
    catch(IOException ioex){
      log.error("IO Exception thrown when trying to write response", ioex.getMessage());
    }
  }
}

Answer 1

You should either register your own HttpMessageConvertor (it should now be using a StringHttpMessageConverter, which outputs text/plain, see http://static.springsource.org/spring/docs/3.1.x/javadoc-api/org/springframework/http/converter/StringHttpMessageConverter.html), or you should handle the whole request yourself.

The latter is probably the easiest, but the least Spring-MVC’ish. You just return null, and use the response object to write the result.

The Spring-MVC way would be to implement the mapping from your internal objects to XML in a HttpMessageConverter, and return your internal object together with @ResponseBody from your MVC controller function.