New event on openfire server


I’ve downloaded the OpenFire server and successfully installed it on my Windows and my prime goal is to use it as my Game server so that my game which is installed on Android and iOS devices will be able to communicate on different OS, meaning - user with iPhone can play against user with Android phone

The problem i’m trying to solve now is how can i add new event on the server so once the client sends it to the server it will, for example, look for another user which is connected at the same time to the server and start a game between the two of them.

?Can someone please direct me to the main classes i need to start overviewing