how do I get the name of a file type part

I send a file from a jsp to a servlet where I receive it in a getPart but I can not even get the name of it. So I am taking the file, but it results in null, and I already made a verification and if I am receiving the file.

 Part archivo = request.getPart("dataDoc");

  String fileName = Paths.get(archivo.getSubmittedFileName()).getFileName().toString();