title: 'Too many body parameters' Exception on Feign Client
body: <p>I am using Springs Feign Client functionality to communicate from one micro service to another.</p>
  
  <p>Now, the called service exposes a REST interface which accepts a file and a related (JSON)Object. </p>
  
  <pre><code>@RequestMapping(value = {CONVERT_PATH, APPLICATION_PATH + CONVERT_PATH}, method = RequestMethod.POST, produces = CONTENT_TYPE)
      public ResponseEntity&lt;InputStreamResource&gt; convert(@RequestPart("file") MultipartFile file, @RequestParam("input") Input in) {...}
  </code></pre>
  
  <p>This interface is functioning fine, I have verified this by sending a valid multipart/mixed entity to it from a different source.</p>
  
  <p>Then, in my other service, I have setup a matching feign client to use this interface:</p>
  
  <pre><code>@FeignClient("convert")
  public interface ConvertClient {
      @RequestMapping(value = CONVERT_PATH, method = RequestMethod.POST, consumes = "multipart/mixed")
      ResponseEntity&lt;InputStreamResource&gt; convert(@RequestPart("file") MultipartFile file, @RequestPart("input") Input in);
  }
  </code></pre>
  
  <p>Again, the connection from one service to the other is working, Ive verified this with a different request interface in the feign client (one which does not use multiple parts).</p>
  
  <p>When I try to build the (client)service with this particular interface-method I get the following exception:</p>
  
  <pre><code>FactoryBean threw exception on object creation; 
  nested exception is java.lang.IllegalStateException: Method has too many Body parameters: 
  public abstract org.springframework.http.ResponseEntity &lt;..&gt;.feign.ConvertClient.convert(org.springframework.web.multipart.MultipartFile,&lt;..&gt;.Input)
  </code></pre>
  
  <p>Is there anything I can do to make this work? 
  Its possible to reach the REST interface as i stated, and different feign calls are working. If I am not mistaken this should work. 
  Is Springs Feign just not supporting multipart/mixed for feign interfaces?</p>