Connecting unreal mobile game to Java server?

Hello Forum Members,

I am building an android game which is similar to poker in unreal engine 4, it is a multiplayer, clients will join, play and leave. I have a java server for handling all the room, join management.

Please tell me how do I connect and send receive messages to this server or if there is any other way? Can I have a unreal server which can handle so many users simultaneously?

Please reply fast. Give me any clue.