Android + App engine: user.getUserID() is null in endpoint

Question

I have an Android application with GAE server. I tried to authenticate the user as described on developers.google.com, I added the user parameter to the endpoint methods etc. I get a User which is not null, but this method getUserId() returns null. It is similar to this, rather old problem: Function User.getUserId() in Cloud endpoint api returns null for a user object that is not null But I still don't know how to work around it. How do you handle this error? Have you ever encountered it?

In android client here's what I did (its simplified) :

credentials = GoogleAccountCredential.usingAudience(getApplicationContext(),         "server:client_id:" + WEB_CLIENT_ID);
credentials.setSelectedAccountName(accountName);
WarriorEntityEndpoint.Builder endpointBuilder = new WarriorEntityEndpoint.Builder(AndroidHttp.newCompatibleTransport(), new GsonFactory(), credentials);
warriorEntityEndpoint = endpointBuilder.build();

new AsyncTask<Void, Void, Void>() {
    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub
        try {
            warriorEntityEndpoint.getWarrior().execute();
        } catch (Exception e) {
        }
        return null;
    }
}.execute();

And on GAE:

@Api(name = "warriorEntityEndpoint", namespace = @ApiNamespace(ownerDomain = "szpyt.com", ownerName = "szpyt.com", packagePath = "mmorpg.monsters"),
version = "version1",
scopes = {"https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/userinfo.profile"},
clientIds = {Constants.ANDROID_CLIENT_ID, Constants.WEB_CLIENT_ID},
audiences = {Constants.ANDROID_AUDIENCE})
public class WarriorEntityEndpoint {
private static final Logger log = Logger.getLogger(WarriorEntityEndpoint.class.getName());
@ApiMethod(name = "getWarrior")
public WarriorEntity getWarrior(User user) throws OAuthRequestException, IOException  {
    log.log(Level.SEVERE, "this gives correct email: " + user.getEmail());
    log.log(Level.SEVERE, "this is null: " + user.getUserId());

I have also another very important question: is this user authenticated, if getMail() gives me correct account, but getUserId() gives null? I read that user object should be null if it was not authenticated but I am not sure any more... I'm using App engine SDK 1.8.7. I'm testing on a real device and backend deployed to GAE.

Answer 1

I asked the same question a while ago and got an answer. See link:

Function User.getUserId() in Cloud endpoint api returns null for a user object that is not null

The cause is a bug on appengine.