Question from beginner

I’m very rusty on my java and even more so on creating web applications with java. I was just wondering if its possible to have my web app connect as a user to talk.google.com 24/7 and if the user disconnects some how, that it reconnects by itself? how would i be able to do all this?

I was planning on hosting this on google app engine.

Thanks in advance and I hope this makes sense,