There shouldn't be any issues of creating a telnet server with java.
If have created
a "telnet" server to control my java program. I can connect it with telnet and
then remotely administer my java program. First you must create

ServerSocket to listen to telnet port.

Then you get the socket from ServerSocket.accept()
when client comes.
Then you just create the input and output -streams
and you can send and receive characters. There are lot of examples about this on the net.