code: public static String getPostDataAsString(HttpServletRequest request) throws IOException {
  
          try (InputStreamReader reader = new InputStreamReader(request.getInputStream(), "UTF-8")) {
              return (getReaderContentAsString(reader));
          }
      }
docs: Reads the POST data from a request into a String and returns it.
  
  @param request the HTTP request containing the POST data
  @return the POST data as a String instance
  @throws IOException if any error occurs while reading the POST data