I started with Android few years ago and now I need XMPP to support instant messaging between android devices.
I created SpringBoot Server Application (simple REST API with Controller) for HTTP requests which is connected to MongoDB database to provide/store user data and it uses SmackCCSClient component as client for Google CCS Server (based on XMPP) and on Client side GoogleCloudMessaging API on Android and everything has been working perfectly.
Now, I have to implement the same thing but without GCM, mine XMPPServer and it's Android XMPPClient for Android which will handle communication between devices and server.
Could you suggest the simplest XMPP Server(openfire,ejabber,...) or Java component which will turn Spring Server (HTTP) into HTTP + XMPP server cause I am not experienced with installing servers and heavy backend apps.