RespositoryRestController.java

MediaType acceptType = config.getDefaultMediaType();
    HttpMessageConverter converter = findWriteConverter(resource.getClass(), acceptType);
    // If an Accept header is specified that isn't the catch-all, try and find a converter for it.
    if(null == converter) {
      for(MediaType mt : request.getHeaders().getAccept()) {
        if(MediaType.ALL.equals(mt)) {
          continue;
        }