public static void listen(StringTokenizer st) {
try {
if (port[0] == -1) {
if (st.hasMoreTokens()) {
try {
port[0] = Integer.parseInt(st.nextToken());
} catch (NumberFormatException nfe) {
System.err.println("listen: incorrect port name");
return;
}
if (port[0] < 0 || port[0] > 65535) {
System.err.println("listen: port name is out of range 0 - 65535");
port[0] = -1;
return;
}
if (!serverSocket.isOpen()) {
serverSocket = ServerSocketChannel.open();
serverSocket.configureBlocking(false);
}
serverSocket.socket().bind(new InetSocketAddress(port[0]));
serverSocket.register(selector, SelectionKey.OP_ACCEPT);
} else {
System.err.println("listen: no port name");
}
} else {
System.err.println("Error: already listening port " + port[0]);
}
} catch (Exception expt) {
Utils.printErrorAndExit(expt.getMessage());
}
}
public static void sendMessage(SocketChannel clientSocket, byte[] message) {
try {
if (clientSocket.isConnected()) {
clientSocket.write(ByteBuffer.wrap(message));
}
} catch (Exception expt) {
Utils.printErrorAndExit("Error: " + expt.getMessage());
}
}
public static void disconnectClient(SocketChannel sc) {
String clientName = getNickFromSocket(sc);
if (clientName == null) {
Utils.printErrorAndExit("Error: it could not happen");
}
sendMessage(sc, MessageUtils.bye());
clients.remove(clientName);
Utils.tryClose(sc);
notifyAllClients(clientName + " leave this chatroom");
System.out.println(clientName + " leave this chatroom");
}
public static void main(String[] args) {
port[0] = -1;
try {
reader = new BufferedReader(new InputStreamReader(System.in));
clients = new LinkedHashMap<String, SocketChannel>();
selector = Selector.open();
List<SocketChannel> anonymousClients = new ArrayList<SocketChannel>();
serverSocket = ServerSocketChannel.open();
serverSocket.configureBlocking(false);
while (true) {
readCommand();
checkClients(anonymousClients);
}
} catch (Exception expt) {
Utils.printErrorAndExit("Error: " + expt.getMessage());
}
}
public static void kill(StringTokenizer st) {
try {
if (st.hasMoreTokens()) {
String clientName = st.nextToken();
if (clients.containsKey(clientName)) {
SocketChannel clientChannel = clients.get(clientName);
clients.remove(clientName);
sendMessage(clientChannel, MessageUtils.bye());
notifyAllClients(clientName + " leave this chatroom");
System.out.println(clientName + " leave this chatroom");
Utils.tryClose(clientChannel);
} else {
System.err.println("kill: no such client");
}
} else {
System.err.println("kill: no client name");
}
} catch (Exception expt) {
Utils.printErrorAndExit(expt.getMessage());
}
}
public static void stop() {
try {
if (port[0] != -1) {
for (Entry<String, SocketChannel> client : clients.entrySet()) {
if (client.getValue().isConnected()) {
sendMessage(client.getValue(), MessageUtils.bye());
Utils.tryClose(client.getValue());
}
}
Utils.tryClose(serverSocket);
clients.clear();
port[0] = -1;
} else {
System.err.println("stop: already stopped");
}
} catch (Exception expt) {
Utils.printErrorAndExit(expt.getMessage());
}
}
public static void checkClients(List<SocketChannel> anonymousClients) {
try {
if (selector.selectNow() == 0) {
return;
}
Set<SelectionKey> keys = selector.selectedKeys();
for (SelectionKey key : keys) {
if ((key.readyOps() & SelectionKey.OP_ACCEPT) == SelectionKey.OP_ACCEPT) {
SocketChannel clientSocket = serverSocket.accept();
if (clientSocket == null) {
System.err.println("Error: can not accept");
continue;
}
anonymousClients.add(clientSocket);
clientSocket.configureBlocking(false);
clientSocket.register(selector, SelectionKey.OP_READ);
} else if ((key.readyOps() & SelectionKey.OP_READ) == SelectionKey.OP_READ) {
SocketChannel clientSocket = (SocketChannel) key.channel();
ByteBuffer bytes = ByteBuffer.allocate(4096);
if (clientSocket.read(bytes) != -1) {
byte[] message = bytes.array();
switch (message[0]) {
case 1:
{
String nick = MessageUtils.parseMessage(message).first;
if (!checkMessage(nick, "", clientSocket)) {
continue;
}
if (clients.containsKey(nick) || nick.length() > 32) {
if (nick.length() > 32) {
sendMessage(
clientSocket, MessageUtils.error("<server>: your nick is too long"));
} else {
sendMessage(
clientSocket,
MessageUtils.error("<server>: another user is using this nick"));
}
sendMessage(clientSocket, MessageUtils.bye());
anonymousClients.remove(clientSocket);
Utils.tryClose(clientSocket);
} else {
System.out.println(nick + " enter this chatroom");
notifyAllClients(nick + " enter this chatroom");
sendMessage(
clientSocket,
MessageUtils.message("<server>", "Wellcome, your nick is " + nick));
anonymousClients.remove(clientSocket);
clients.put(nick, clientSocket);
}
break;
}
case 2:
{
String nick = getNickFromSocket(clientSocket);
if (nick == null) {
Utils.printErrorAndExit("Error: it could not happen");
}
Utils.Pair<String, String> pair = MessageUtils.parseMessage(message);
if (!checkMessage(pair.first, pair.second, clientSocket)) {
continue;
}
if (!pair.first.equals(nick)) {
System.out.println("Cheater: " + nick);
sendMessage(clientSocket, MessageUtils.message("<server>", "do not cheat"));
}
for (Entry<String, SocketChannel> client : clients.entrySet()) {
if (!clientSocket.equals(client.getValue())) {
sendMessage(client.getValue(), MessageUtils.message(nick, pair.second));
}
}
break;
}
case 3:
disconnectClient(clientSocket);
break;
case 127:
{
String nick = getNickFromSocket(clientSocket);
Utils.Pair<String, String> pair = MessageUtils.parseMessage(message);
if (!checkMessage(pair.first, pair.second, clientSocket)) {
continue;
}
if (!pair.first.equals(nick)) {
System.out.println("Cheater: " + nick);
sendMessage(clientSocket, MessageUtils.message("<server>", "do not cheat"));
}
System.out.println(nick + ": " + pair.second);
break;
}
default:
System.out.println("Bad message from " + getNickFromSocket(clientSocket));
sendMessage(clientSocket, MessageUtils.message("<server>", "bad message"));
break;
}
} else {
disconnectClient(clientSocket);
}
}
}
keys.clear();
} catch (Exception expt) {
expt.printStackTrace();
Utils.printErrorAndExit(expt.getMessage());
}
}
public static void readCommand() {
try {
if (!reader.ready()) {
return;
}
StringTokenizer tokens = new StringTokenizer(reader.readLine());
if (tokens.hasMoreTokens()) {
switch (tokens.nextToken()) {
case "/listen":
listen(tokens);
break;
case "/stop":
stop();
break;
case "/list":
if (port[0] == -1) {
System.err.println("Error: start listening before");
}
for (Entry<String, SocketChannel> client : clients.entrySet()) {
System.out.println(client.getKey());
}
if (clients.entrySet().isEmpty()) {
System.out.println("list: no clients online");
}
break;
case "/send":
if (tokens.hasMoreTokens()) {
String name = tokens.nextToken();
if (clients.containsKey(name)) {
if (tokens.hasMoreTokens()) {
sendMessage(
clients.get(name),
MessageUtils.message("<server>", getMessageFromTokens(tokens)));
} else {
System.err.println("send: message is empty");
}
} else {
System.err.println("send: no such client");
}
} else {
System.err.println("send: no client name");
}
break;
case "/sendall":
if (tokens.hasMoreTokens()) {
notifyAllClients(getMessageFromTokens(tokens));
} else {
System.err.println("sendall: message is empty");
}
break;
case "/kill":
kill(tokens);
break;
case "/exit":
if (port[0] != -1) {
stop();
}
Utils.tryClose(selector);
System.exit(0);
break;
default:
System.err.print("Error: unknown command");
break;
}
} else {
System.err.println("Error: empty input");
}
} catch (Exception expt) {
Utils.printErrorAndExit(expt.getMessage());
}
}