GoogleOauthExample.scala

class GoogleClient() {
  import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeTokenRequest
  import com.google.api.client.http.javanet.NetHttpTransport
  import com.google.api.client.json.jackson2.JacksonFactory
  import com.google.api.services.oauth2.Oauth2
  import com.google.auth.http.HttpCredentialsAdapter
  import com.google.auth.oauth2.{AccessToken, UserCredentials}
  import scala.jdk.CollectionConverters._

  // shared data
  val scopes =List(
    "https://www.googleapis.com/auth/userinfo.email",
    "https://www.googleapis.com/auth/userinfo.profile",
  )
  val clientid = "11111-blahblah.apps.googleusercontent.com"

  // client side
  val redir = "http://localhost:8080"
  val oauthUrl = s"https://accounts.google.com/o/oauth2/auth?scope=${scopes.mkString(" ")}&response_type=code&access_type=offline&client_id=${clientid}&redirect_uri=${redir}"
  val clientCode = java.net.URLDecoder.decode("4...hKuI", "UTF-8")


  // server side
  val clientsecret = "PYbo...sCPD"
  val tokenUri = new URI("https://oauth2.googleapis.com/token")
  val appName = "MyApp"
  private val transport = new NetHttpTransport()
  private val factory = new JacksonFactory()

  val tokenRes = new GoogleAuthorizationCodeTokenRequest(
    transport,
    factory,
    clientid,
    clientsecret,
    clientCode,
    "http://localhost:8080"
  ).setScopes(scopes.asJava)
    .execute();

  val at = tokenRes.getAccessToken
  val rt = tokenRes.getRefreshToken

  println(s"at=$at, rt=$rt")
  val creds = UserCredentials.newBuilder()
    .setAccessToken(new AccessToken(at, null))
    .setRefreshToken(rt)
    .setClientId(clientid)
    .setClientSecret(clientsecret)
    .setTokenServerUri(tokenUri)
    .build()

  //  creds.refresh()

  val initializer = new HttpCredentialsAdapter(creds)

  val oauth2 = new Oauth2.Builder(transport, factory, initializer)
    .setApplicationName(appName)
    .build();
  println(oauth2.userinfo().get().execute())
  println(oauth2.userinfo().v2().me().get().execute())
}