Authenticate with "Google Sign In" with Spray

I was able to find an example of some kind of google authentication in an unrelated spray fork . According to Google+ documentation Login and Java Example This is not exactly what I expect. It doesn't use google API packages for example. com.google.api.client.googleapis.auth.oauth2

, it has some manual ways for example. private val authServer = Uri("https://accounts.google.com/o/oauth2/auth")

, it mentions some things that are not mentioned at all in the java example, eg. redirect_uri

and grant_type

so on. etc. I think the example is only for "Authorization", that is, authorizing your application to make google api calls to get user data, so they cannot be used for authentication / login.

What's the difference here? Are there any examples of how to do this using Google+ login? BONUS: Why isn't the plug installed?

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