The Google OAuth Client Library for Java is designed to work with any OAuth service on the web, not just with Google APIs. The library is built on the Google HTTP Client Library for Java, and it supports Java 7 (or higher) standard (SE) and enterprise (EE), Android 4.0 (or higher), and Google App Engine.

For access to Google APIs, see the Google API Client Library for Java.

This is an open-source library, and you can access the source on GitHub. Contributions are welcome.