Send information to other servers without the use of players.

Hi there, I'm creating a minigame network.

I need to be able to update signs, receiving data from external servers on the network, but I have a slight problem.

My external servers need to send information to my hub server when no players are online, which means I cannot use [player].sendPluginMessage().

I believe I can use sockets, but I have no knowledge of this.

Any help would be greatly appreciated.