code: public boolean isValid(HttpServletRequest request, String challenge, String response) {
      String remoteAddr = request.getRemoteAddr();
      log.info("Challenge Field Name = [{}]", challenge);
      log.info("Response Field Name = [{}]", response);
      if(challenge != null && response != null && challenge.trim().length() > 0) {
        return reCaptcha.checkAnswer(remoteAddr, challenge, response).isValid();
      } else {
        return false;
      }
    }
docs: Validates the captcha response.
  
  @param request
  @param challenge
  @param response
  @return