— Scott McNealy, Sun Microsystems Chairman, President and ceo

 Let me rephrase the problem: how can 
you make a server that can handle multiple 
clients concurrently??? This would never 
work for a chat server, for instance.
A:
Ah, that’s simple, really. Use separate 
threads, and give each new client Socket to a 
new thread. We’re just about to learn how to 
do that!

---

486
 
chapter 15
Writing a Chat Client
We’ll write the Chat client application in two stages. First we’ll 
make a send-only version that sends messages to the server but 
doesn’t get to read any of the messages from other participants 
(an exciting and mysterious twist to the whole chat room 
concept).
Then we’ll go for the full chat monty and make one that both 
sends and receives chat messages.
Version One: send-only
public class SimpleChatClientA {

JTextField outgoing;
PrintWriter writer;
Socket sock;
public void go() {
// make gui and register a listener with the send button
// call the setUpNetworking() method
} 
private void setUpNetworking() {
// make a Socket, then make a PrintWriter
// assign the PrintWriter to writer instance variable
}
public class SendButtonListener implements ActionListener {
public void actionPerformed(ActionEvent ev) {
// get the text from the text field and 
// send it to the server using the writer (a PrintWriter)
}
} // close SendButtonListener inner class
} // close outer class
Code outline
Type a message, then press ‘Send’ 
to send it to the server. We 
won’t get any messages 
FROM the 
server in this version, so there’s 
no scrolling text area.