Example web app which uses Spring Social Google.
https://github.com/GabiAxel/spring-social-google
Set up a project at https://console.developers.google.com/ and add the OAuth2 client ID and secret to the "google.clientId" and "google.clientSecret" environment properties when running the app.
To run with Maven: mvn tomcat7:run -Dgoogle.clientId=CLIENT_ID -Dgoogle.clientSecret=CLIENT_SECRET
The application will be available at http://localhost:8080/