Getting user's email address authenticated by OAuth2

Question

I'm trying to to come up with a working example to log into the system using Google's OAuth2 and then ask for user's information (like name and/or email). This is as far as I managed to go so far:

InputStream in = Application.class.getResourceAsStream("/client_secret.json");
GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JacksonFactory.getDefaultInstance(), new InputStreamReader(in));

// Build flow and trigger user authorization request.
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
    GoogleNetHttpTransport.newTrustedTransport(),
    JacksonFactory.getDefaultInstance(),
    clientSecrets,
    Arrays.asList(
        PeopleScopes.USERINFO_PROFILE
    )
)
    .setAccessType("offline")
    .build();


GoogleTokenResponse response = flow
    .newTokenRequest(code)
    .setRedirectUri("http://example.com/oauth2callback")
    .execute();

Credential credential = flow.createAndStoreCredential(response, null);
Gmail service = new Gmail.Builder(GoogleNetHttpTransport.newTrustedTransport(),
    JacksonFactory.getDefaultInstance(),
    credential
)
    .setApplicationName("My App")
    .build();

Oauth2 oauth2 = new Oauth2.Builder(new NetHttpTransport(), new JacksonFactory(), credential)
    .setApplicationName("My App")
    .build();
Userinfoplus userinfo = oauth2.userinfo().get().execute();
System.out.print(userinfo.toPrettyString());

And works perfectly except the fact that the returned user info does not have my email in it! The printed info are:

{
  "family_name" : "...",
  "gender" : "...",
  "given_name" : "...",
  "id" : "...",
  "link" : "https://plus.google.com/+...",
  "locale" : "en-GB",
  "name" : "... ...",
  "picture" : "https://.../photo.jpg"
}

But I'm looking for the user's email (the one that he/she used to log into the system). How can I get user's email address?

BTW, if you wonder; PeopleScopes.USERINFO_PROFILE is:

https://www.googleapis.com/auth/userinfo.profile

Answer 1

I found it, it has to be:

GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
    GoogleNetHttpTransport.newTrustedTransport(),
    JacksonFactory.getDefaultInstance(),
    clientSecrets,
    Arrays.asList(
        PeopleScopes.USERINFO_PROFILE,
        PeopleScopes.USERINFO_EMAIL
    )
)

And PeopleScopes.USERINFO_EMAIL stands for:

https://www.googleapis.com/auth/userinfo.email

Now the userinfo has got email address too.