How to capture email address in app engine?

Question

I have created an application in app engine for our company. Only the domain users can access the application .How can i capture the email address in Google App Engine without any authentication ? I tried to capture the email address on application using

   UserService userService = UserServiceFactory.getUserService();
   currentUser=userService.getCurrentUser();

but it shows a popup saying that your email address will be captured. I don't want to confuse the domain users with that popup. In App script it simply captures the email address using

var email = Session.getActiveUser().getEmail();
Logger.log(email);

Is there any way to bypass the authentication popup for my domain users accessing the webapp ?

Answer 1

You can't. That's the whole point of authentication: user has to give your app permission to access certain data in their profile (including email).