How to handle (failed) login attempts with Smack XMPP API?

Not sure if I understand what you are asking but if it's "How can I determine the reason for a failed login attempt with Smack?" then here is my answer.

Actually, the main problem was that when I tried to login using an invalid username/password, some exception was thrown (As well as an information display that I set up), but the application wouldn't let me log in again (As if I corrected my data and clicked the button again).

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.