So, I was wondering if its ok to have something like this in the Controller (for each field that may need it):

  if(!formFile.getContentType().startsWith("image/")){
                bindingResult.rejectValue("formFile","MultipartInvalidFile");
                return "fileForm";

Or is this should be handle in the service.class and then send to the controller?:

AwesomeService.class:

 if(!formFile.getContentType().startsWith("image/")){
             throw new exception... (and somehow send it to the controller->view?)

ps: all its example code, sorry if there are syntax errors