Get JSON Response when sending a MULTI_PART_DATA

[VansFannel]

I'm following this example, https://github.com/SpringSource/spri...aActivity.java to send an Image to a WCF RestFul web service.

[OperationContract]
[WebInvoke(Method = "POST",
    ResponseFormat = WebMessageFormat.Json,
    BodyStyle = WebMessageBodyStyle.Bare,
    UriTemplate = "uploadImage/")]
Boolean UploadImage(Stream fileContents);

As you can see, I want to return a Boolean to indicate if image has been saved successfully or not. But, when I've tried to update code to get JSON response, I get an exception:

This is my code to send image to server:

public static Boolean sendImage(String url, String filePath, long eReportId)
{
	try
	{
		MultiValueMap<String, Object> formData;

		Resource resource = new FileSystemResource(filePath);

		// populate the data to post
		formData = new LinkedMultiValueMap<String, Object>();
		formData.add(OrderSpringController.FILE, resource);

		HttpHeaders requestHeaders = new HttpHeaders();
		requestHeaders.setAccept(Collections.singletonList(new MediaType("application","json")));

		// Sending multipart/form-data
		requestHeaders.setContentType(MediaType.MULTIPART_FORM_DATA);

		// Populate the MultiValueMap being serialized and headers in an HttpEntity object to use for the request
		HttpEntity<MultiValueMap<String, Object>> requestEntity = 
				new HttpEntity<MultiValueMap<String, Object>>(formData, requestHeaders);

		GsonHttpMessageConverter messageConverter = new GsonHttpMessageConverter();
		List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
		messageConverters.add(messageConverter);

		// Create a new RestTemplate instance
		RestTemplate restTemplate = new RestTemplate(true);
        restTemplate.setMessageConverters(messageConverters);

		// Make the network request, posting the message, expecting a String in response from the server
		ResponseEntity<Boolean> response = restTemplate.exchange(url, HttpMethod.POST, requestEntity,
				Boolean.class);

		// Return the response body to display to the user
		return response.getBody();
	}
	catch (Exception ex)
	{
		ex.printStackTrace();
	}
	return null;
}

And this is the exception:

org.springframework.web.client.RestClientException: Could not write request: no suitable HttpMessageConverter found for request type [org.springframework.util.LinkedMultiValueMap] and content type [multipart/form-data]
	at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:632)
	at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:473)
	at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:438)
	at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:414)
	at es.viacognita.ereports.webservice.OrderSpringController.sendImage(OrderSpringController.java:215)
	at es.viacognita.ereports.EReportsActivity$SendImageAsynTask.doInBackground(EReportsActivity.java:113)
	at es.viacognita.ereports.EReportsActivity$SendImageAsynTask.doInBackground(EReportsActivity.java:1)
	at android.os.AsyncTask$2.call(AsyncTask.java:252)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
	at java.util.concurrent.FutureTask.run(FutureTask.java:137)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1081)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:574)
	at java.lang.Thread.run(Thread.java:1020)

I'm very very new on SpringFramework for Android development.

How can I do to get server's JSON response?