com.google.api.client.http
Interface HttpUnsuccessfulResponseHandler

All Known Implementing Classes:

MockHttpUnsuccessfulResponseHandler

public interface HttpUnsuccessfulResponseHandler

Interface which handles abnormal HTTP responses (in other words not 2XX).

For example, this might be used to refresh an OAuth 2 token:

  public static class RefreshTokenHandler implements HttpUnsuccessfulResponseHandler {
    public boolean handleResponse(
        HttpRequest request, HttpResponse response, boolean retrySupported) throws IOException {
      if (response.statusCode == HttpStatusCodes.STATUS_CODE_UNAUTHORIZED) {
        refreshToken();
      }
      return false;
    }
  }
 

Sample usage with a request factory:

  public static HttpRequestFactory createRequestFactory(HttpTransport transport) {
    final RefreshTokenHandler handler = new RefreshTokenHandler();
    return transport.createRequestFactory(new HttpRequestInitializer() {
      public void initialize(HttpRequest request) {
        request.unsuccessfulResponseHandler = handler;
      }
    });
  }
 

If you have a custom unsuccessful response handler, use this more complex example:

  public static HttpRequestFactory createRequestFactory(HttpTransport transport) {
    final RefreshTokenHandler handler = new RefreshTokenHandler();
    return transport.createRequestFactory(new HttpRequestInitializer() {
      public void initialize(HttpRequest request) {
        request.unsuccessfulResponseHandler = new HttpUnsuccessfulResponseHandler() {
          public boolean handleResponse(
              HttpRequest request, HttpResponse response, boolean retrySupported)
              throws IOException {
            return handler.handleResponse(request, response, retrySupported);
          }
        };
      }
    });
  }
 

Implementations should normally be thread-safe.

Since:

1.4

Author:

moshenko@google.com (Jacob Moshenko)

Method Summary

boolean

handleResponse(HttpRequest request, HttpResponse response, boolean supportsRetry) Handler that will be invoked when an abnormal response is received.

Method Detail

handleResponse

boolean handleResponse(HttpRequest request,
                       HttpResponse response,
                       boolean supportsRetry)
                       throws IOException

Handler that will be invoked when an abnormal response is received. There are a few simple rules that one must follow:

• If you modify the request object or modify its execute interceptors in a way that should resolve the error, you must return true to issue a retry.
• Do not read from the content stream, this will prevent the eventual end user from having access to it.

Parameters:

request - Request object that can be read from for context or modified before retry

response - Response to process

supportsRetry - Whether there will actually be a retry if this handler return true. Some handlers may want to have an effect only when there will actually be a retry after they handle their event (e.g. a handler that implements exponential backoff).

Returns:

Whether or not this handler has made a change that will require the request to be re-sent.

Throws:

IOException