Android - Oauth2, AccountManager and Google: retrieve profile data

Question

I'm making an app that should allow the user to register through its google account. I want to retrieve automatically as many profile infos as I can. I found this very interesting example, which would allow me to get many infos (see step 4 of that demo). Now, how do I use it on android? I saw many examples of how to get the authentication token with the AccountManager with Oauth2 (example), but I don't know what to do from there to make those calls and retrieve those infos. Also in that example the code is in javascript and I don't know how to port it properly to java...
I have already done the google dev console registration stuff.
Are Oauth2 and OpenID the same thing? If not, do I have to use either one OR the other?

Answer 1

Ok, done. As expected, I found all the infos in the docs, and using Google's Oauth2 Playground helped to understand what to send to https://www.googleapis.com/oauth2/v1/userinfo in order to receive the profile data.
In the end, it turns out we don't need to create a client ID in google's dev console to do this.
Now, to the code. The activity:

public class MainActivity extends Activity {

    public Activity mContext;
    private AccountManager accountManager;
    private final String SCOPES = "oauth2:https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile";
    private String authToken;
    private GetProfileDataTask googleTask;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_layout);

        mContext = this;

        accountManager = AccountManager.get(mContext);

        //other stuff here...
    }

    public void getProfileData() {

        accountManager.getAuthTokenByFeatures(
                "com.google", 
                SCOPES, 
                null, mContext, null, null, 
                new AccountManagerCallback<Bundle>() {
                    public void run(AccountManagerFuture<Bundle> future) {

                        try {
                            Bundle bundle = future.getResult();

                            //bundle.getString(AccountManager.KEY_ACCOUNT_NAME);
                            //bundle.getString(AccountManager.KEY_ACCOUNT_TYPE);

                            authToken = bundle.getString(AccountManager.KEY_AUTHTOKEN);

                        } catch (Exception e) {
                            System.out.println("getAuthTokenByFeatures() cancelled or failed:");
                            e.printStackTrace();
                            authToken = "failure";
                        }

                        if(!authToken.equals("failure")) {

                            googleTask = new GetProfileDataTask();
                            googleTask.execute(authToken);
                        }
                    }
                }, null);
    }
}

The AsyncTask that gets the data:

public class GetProfileDataTask extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... tokens) {

        RestTemplate restTemplate = new RestTemplate(false);
        restTemplate.getMessageConverters().add(new StringHttpMessageConverter());

        String json = null;

        try {
                //the response is of type "application/json"
            json = restTemplate.getForObject(
                    "https://www.googleapis.com/oauth2/v1/userinfo" + 
                    "?access_token={token}" + 
                    "&access_token_type=bearer", 
                    String.class, 
                    tokens[0]); //this is the authToken from before, obv

        } catch(RestClientException er) {
            Log.e("GetProfileDataTask", er.toString(), er);
            json = null;
        }

        return json;
    }

    @Override
    protected void onPostExecute(String asyncResult) {

        if(asyncResult != null)
            //do something with your data, for example deserialize it
        else
            //do something else
    }
}

The received json is like this:

{
  "family_name": "Smith", 
  "name": "John Smith", 
  "picture": "https://lh3.googleusercontent.com/-randomlettersandnumbers/AAAAAAAAAAI/AAAAAAAAAAA/morerandomlettersandnumbers/photo.jpg", 
  "locale": "it", 
  "gender": "male", 
  "email": "youremail@whatever.itis", 
  "link": "https://plus.google.com/133780085840848123456", 
  "given_name": "John", 
  "id": "133780085840848123456", 
  "verified_email": true
}