/**
* Process a packet received on multicast or unicast ports. Both ports may be used to send connect
* messages or ordinary messages. Multicast: if from self, ignore. if connect, add or update user,
* and send a connect reply otherwise display message Unicast: (shouldn't get from self) if
* connect, add user otherwise display message
*
* <p>Notes: we could loopback mode inhibit to true, to stop a socket receiving it's own messages,
* but that would stop two clients on the same IP address receiving messages from each other
*
* @param packet
* @param multicast
* @throws IOException
*/
private void processPacket(DatagramPacket packet, boolean multicast) throws IOException {
String message = new String(packet.getData(), 0, packet.getLength());
String type = multicast ? "multicast" : "unicast";
System.out.println(
type
+ " packet received from "
+ packet.getAddress().getHostAddress()
+ ":"
+ packet.getPort()
+ "='"
+ message
+ "'");
// e.g. connect::name=John::host=192.168.2.1::port=8002
String[] tokens = message.split("::");
if (tokens.length == 4
&& tokens[0].equals("connect")
&& tokens[1].startsWith("name=")
&& tokens[2].startsWith("host=")
&& tokens[3].startsWith("port=")) {
String name = tokens[1].substring(5);
String host = tokens[2].substring(5);
int port = Integer.parseInt(tokens[3].substring(5));
User user = new User(name, host, port);
// check to see if trying to add itself:
if (user.equals(this.selfUser)) {
assert (multicast) : "shouldn't receive unicast from self";
System.out.println("ignoring message from self");
return;
}
chatSwing.addUser(user);
// if multicast then must be new user or reconnecting user
// if unicast, then user must already know about me
if (multicast) {
// new user, so send back a connect message
System.out.println("sending back connect message to user " + name);
String message2 =
"connect::name=" + userName + "::host=" + myHostAddress + "::port=" + unicastPort;
SendDatagram.sendDatagram(host, port, message2);
}
} else {
chatSwing.showMessage(message);
}
}
public void sendMessage(User user, String message) throws IOException {
message = "from " + userName + " to " + user.getName() + ": " + message;
SendDatagram.sendDatagram(user.getHost(), user.getPort(), message);
}