Hey Trusell, what's your solution in the end for this problem? I am working on a server too. Something like a IP server to keep track of connecting PCs. I am thinking of just putting it run on a PC and let it run 24/7. Really there is a problem for this?
Do I need something like a web server (e.g. Tomcat Apache)? I thought they were only for hosting website? What if now I just wanna run a Java application as server?
Helps and suggestions in need… Please anyone 
“Web Servers” are really technically just computers. Anyway, you could run it on a PC and it would work fine. You just have to worry about the following:
-If your ISP changes the IP Address of your home (or office or wherever the PC is), you’ll need to update the code that you use to connect to the server
-If you use any type of router, you’ll need to forward the ports your application uses to connect.
-A basic internet connection isn’t enough bandwidth to handle a large-scale application. If you’re programming something that tons of people are going to be connected to and keep retrieving data from, you’re going to need to upgrade to a T1 or T3 internet connection (or whatever they have in your country)
Otherwise, you should investigate a hosting company that allows you to restart your Tomcat / Apache / JVM whenever you want (otherwise you have to wait 24 hours for changes to take place)
Hey thanks for the reply~! I think I roughly know where to start now 