Howdy,
You'll need to use Sockets (java.net package), Streams (java.io), and probably Threads to do this. It's a little too advanced for this forum, though, so I'm just giving you the overview:
Client makes a Socket connection to the server.
Server has a ServerSocket to accept client connections.
Client gets an input stream and output stream from the Socket. Client sends data to the server over the output stream and receives data from the server using the input stream. There are many types of input and output streams, but you might want to look at sending serialized objects using ObjectInputStream and ObjectOutputStream. This can often be eaiser than other streams, but it depends on the kind of data you need to send and receive.
Server does basically the same thing, gets input and output streams from the Socket connection, and sends data and receives data through these streams.
I know there are a couple of books that have chat code in them, but I can't think of the names right now.
good luck,
Kathy
