code: public String getSubmittedFileName() {
          // TODO this method also introduced in servlet 3.1 specification (delegate to part when I adopt servlet 3.1)
          if (submittedFileName == null) {
              String header = part.getHeader(HttpConstants.Header.CONTENT_DISPOSITION);
              if (header == null) {
                  return null;
              }
  
              for (String headerPart : header.split(";")) {
                  if (headerPart.trim().startsWith("filename")) {
                      submittedFileName = headerPart.substring(headerPart.indexOf('=') + 1).trim().replace("\"", "");
                      break;
                  }
              }
          }
  
          return submittedFileName;
      }
docs: Retrieves the filename specified by the client.
  @return