chatclient.java

chatClient.java, chatServer.java, chatHandler.java

import java.net.*;
import java.io.*;

public class ChatClient {

	ChatFrame gui;
	String name;

	InetAddress group;
	MulticastSocket socket;
	int port = 6789;

	public ChatClient(String name) {
		this.name = name;

		// GUI Create GUI and handle events:
		// After text input, sendTextToChat() is called,
		// When closing the window, disconnect() is called. 

		gui = new ChatFrame("Chat with IP-Multicast");
		gui.input.addKeyListener (new EnterListener(this,gui));
		gui.addWindowListener(new ExitListener(this));

//		In order for a host to receive a multicast data, 
//		the receiver must register with a group, by creating a MulticastSocket on a port and call the joinGroup() method.

		try {
			socket = new MulticastSocket(port);
			group = InetAddress.getByName("226.1.3.5");
			socket.joinGroup(group);
			gui.output.append("Connected...\n");

			// waiting for and receiving messages 

			while (true) {
				byte[] buffer = new byte[1000];
				DatagramPacket datagram = new DatagramPacket(buffer,buffer.length) ;
				socket.receive(datagram);
				String message = new String(datagram.getData());
				gui.output.append(message);
			}
		} catch (IOException e) { 
			e.printStackTrace(); 
		}
	}

	public void sendTextToChat(String message) {
		String mes = message;
		message = name+": "+message+"\n";
		byte[] buf = (message).getBytes();
		DatagramPacket dg = new DatagramPacket(buf,buf.length,group,port);
		try { 
			socket.send(dg);
		}
		catch (IOException ex) { 
			System.out.println(ex);
		}
	}

	public void disconnect() {}


	public static void main(String args[]) {
		if (args.length!=1) 
			throw new RuntimeException ("Syntax: java ChatClient <name>"); 
		ChatClient client = new ChatClient(args[0]);
	}
}