I've recently studied on Java socket programming and have successfully created a simple chat app like IM. It works fine within my company network (Intranet environment), but what if I wanted to let it works across internet?
is there a way of doing that? A simple hint would be helpful!
Well, the short answer is yes. Depending on how you wrote the code used in the intranet will determine how difficult it is to change for the internet. The thing to consider about moving it out onto the inter net is "How am I going to connect to other users? How am I going to determine their IP addresses? Should I use a central server that dishes out IP addresses of those connected?"
Socket communication works great for chat clients, you just need to determine whether you are trying to make it like mIRC where you have multiple people connected to the same chat room, or whether you are going to have one-on-one connections. That will determine your strategy.