code: public OauthData getOauthData(String apiKey, String secretKey, TokenType grantType, boolean autoSetRequestToken)
              throws SignitException {
          if (apiKey == null || secretKey == null) {
              throw new SignitException("请完善开发者账户数据");
          }
          TokenType tmpGrantType = grantType != null ? grantType : TokenType.CLIENT_CREDENTIALS;
          String response = httpClient.withAuth(auth)
                  .withGetParam(RequestParam.CLIENT_ID, apiKey)
                  .withGetParam(RequestParam.CLIENT_SECRET, secretKey)
                  .withGetParam(RequestParam.GRANT_TYPE, tmpGrantType.name()
                          .toLowerCase())
                  .get(OAUTH_TOKEN_URL)
                  .getLastResponse();
          JSONObject data = JSON.parseObject(Validator.notNull(response, "请求token数据失败"));
          if (data != null && autoSetRequestToken) {
              auth.setAccessToken(Validator.notNull(data.getString("access_token"), "token获取失败"));
          }
          return FastjsonDecoder.decodeAsBean(response, OauthData.class);
      }
docs: 可用单独授权，或者可单独调用只获取token