HttpRequestInitializer 需要在失败时执行自动重试。一个简单的 HttpRequestInitializer 可以使用 com.google.api.client.auth.oauth2.Credential 具体如下：

private HttpRequestInitializer buildInitializer(Credential credential) {
    return httpRequest -> {
      // handles abnormal HTTP responses (non 2XX responses)
      final HttpUnsuccessfulResponseHandler unsuccessfulResponseHandler =
          new HttpBackOffUnsuccessfulResponseHandler(new ExponentialBackOff())
              .setSleeper(Sleeper.DEFAULT);
      /*
      this is designed to work with only one HttpRequest at a time.
      Hence, a new instance of HttpBackOffIOExceptionHandler with new instance of
      BackOff is created for each instance of HttpRequest
      */
      HttpBackOffIOExceptionHandler httpBackOffIOExceptionHandler =
          new HttpBackOffIOExceptionHandler(new ExponentialBackOff()).setSleeper(Sleeper.DEFAULT);
      httpRequest.setInterceptor(credential).setUnsuccessfulResponseHandler(unsuccessfulResponseHandler)
          .setIOExceptionHandler(httpBackOffIOExceptionHandler)
          .setConnectTimeout((int) TimeUnit.MINUTES.toMillis(3))
          .setReadTimeout((int) TimeUnit.MINUTES.toMillis(3))
          .setThrowExceptionOnExecuteError(false).setSuppressUserAgentSuffix(true);
    };
  }