Authenticating Google's users through Google OpenID Connect
To allow users to be authenticated by third-party applications, it's required that the Identity Provider you are considering to integrate with is trustworthy. Google is a great example of an Identity Provider that meets such a requirement. In addition, Google conforms to the OpenID Connect specification and is OpenID certified, as explained in the Google Identity Platform guide, which is available at https://developers.google.com/identity/protocols/OpenIDConnect.
This recipe shows you how to use Google OpenID Connect and Spring Security OAuth 2.0 to authenticate users who have an account on Google. As described by OpenID Connect, users share their identity information instead of their resources, as allowed by OAuth 2.0.
Note
This recipe is based on the solution provided by Eugen Parachiv at http://www.baeldung.com/spring-security-openid-connect.
Getting ready
To run this recipe, you will need Java 8, Maven, Spring Web, and Spring Security...