Авторизация Oauth2

am.getAuthToken(
    myAccount_,                     // Account retrieved using getAccountsByType()
    "Manage your tasks",            // Auth scope
    options,                        // Authenticator-specific options
    this,                           // Your activity
    new OnTokenAcquired(),          // Callback called when a token is successfully acquired
    new Handler(new OnError()));

public class OnError implements Handler.Callback {
        @Override
        public boolean handleMessage(Message msg) {
 
            return false;
        }
    }
 
    private class OnTokenAcquired implements AccountManagerCallback<Bundle> {
        @Override
        public void run(AccountManagerFuture<Bundle> result) {
            // Get the result of the operation from the AccountManagerFuture.
            Bundle bundle = null;
            try {
                bundle = result.getResult();
            } catch (OperationCanceledException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (AuthenticatorException e) {
                e.printStackTrace();
            }
 
            // The token is a named value in the bundle. The name of the value
            // is stored in the constant AccountManager.KEY_AUTHTOKEN.
            String token = bundle.getString(AccountManager.KEY_AUTHTOKEN);
        }
    }