谷歌验证码总是失败，没有错误代码

Question

将reCAPTCHA v2 API添加到网页中，我无法让它工作。我已经将密钥配置为在html页面中添加了验证码

    <!-- Google reCAPTCHA -->
    <script th:src="@{https://www.google.com/recaptcha/api.js}"></script>

然后是div元素

<div class="g-recaptcha" data-sitekey="XXXXXXXXXXXXXXXXXXXXXX"></div>

在服务器端（使用Spring）

  @RequestMapping(value = "/contact", method = RequestMethod.POST)
  public Callable<String> contactQuery(final @ModelAttribute("contact") @Valid ContactForm contactForm,
      final @RequestParam("g-recaptcha-response") String captchaResponse, final BindingResult bindingResult,
      final Model model) {
   .....
  }

然后在另一个班级

@Service
public class ReCaptchaResponseVerfier {

  @Resource
  private Environment environment;

  private static final Logger LOGGER = LoggerFactory.getLogger(ReCaptchaResponseVerfier.class);

  @Async
  public Future<GoogleCaptchaResponseData> isCaptchaResponseValid(String captchaResponse) throws InterruptedException,
      ExecutionException {

    LOGGER.debug(" Validating captcha {}", captchaResponse);

    if (captchaResponse.isEmpty()) {
      GoogleCaptchaResponseData response = new GoogleCaptchaResponseData();
      response.setSuccess(false);
      response.setErrorCodes("The \"I am not a robot\" genie says you didn't verify, please do so.");
      return new AsyncResult<GoogleCaptchaResponseData>(response);
    }

    AsyncRestTemplate restTemplate = new AsyncRestTemplate();

    Map<String, String> uriVariables = new HashMap<String, String>();


    ListenableFuture<ResponseEntity<GoogleCaptchaResponseData>> futureResponse = restTemplate.postForEntity(
        "https://www.google.com/recaptcha/api/siteverify", buildCaptachRequest(captchaResponse),
        GoogleCaptchaResponseData.class);

    GoogleCaptchaResponseData response;
    response = futureResponse.get().getBody();

    return new AsyncResult<GoogleCaptchaResponseData>(response);

  }

  private HttpEntity<GoogleCaptchaRequestData> buildCaptachRequest(String captchaResponse) {
    GoogleCaptchaRequestData request = new GoogleCaptchaRequestData();

    request.setResponse(captchaResponse);
    request.setSecret(environment.getProperty("google.recaptcha.secret"));

    return new HttpEntity<GoogleCaptchaRequestData>(request);
  }

但是，我总是获得成功：即使验证码在页面上匹配，也会出现错误的响应。