How to declare global variables in Android?

Question

I am creating an application which requires login. I created the main and the login activity.

In the main activity onCreate method I added the following

Answer 1

On activity result is called before on resume. So move you login check to on resume and your second login can be blocked once the secomd activity has returned a positive result. On resume is called every time so there is not worries of it not being called the first time.