Chat program: how server distinguishes each client connected to it

My task is to make a conference chat program with GUI wherein several clients may connect to the server.

I'm just starting to develop my code and I'm stuck with these problems:


One client sends a message to the server by pushing the button 'SEND'. The task of the server is to send this message to all clients connected to it.



Each of the clients has a name (i.e. Client1, Client2). How will the server know which of the clients sent a message because the server needs to send this message to the clients:
(for example Client1 was the one who sent the message)

Code:

---

Client1: Hello!

---

Is there a way for the server to distinguish between the sockets connected to it, send messages to all the sockets connected to it, and choose a particular socket to send a message?

Thanks for the future help! :)

Have a look on getInetAddress() method of Socket class, which returns a reference to InetAddress class , and getHostAddress() method of InetAddress class which returns a textual representation of IP address of the remote machine to which the socket is connected.

In my project a ServerThread is created to deal with any requests from a client.

The client logs in with a username which is then set in a field on that thread.

The server has a hashtable of all the connected sockets with the username as the key.

It will know which client sent something as it would have come from that clients thread and it can reference the username