Nio идентификация клиента по каналу SocketChannel

   Set<SelectionKey> readyKeys = selector.selectedKeys();
           Iterator<SelectionKey> iterator = readyKeys.iterator();
            while (iterator.hasNext()) {
             SelectionKey key = (SelectionKey) iterator.next();
                iterator.remove();
                try {
                    if (key.isAcceptable()) {
                        ServerSocketChannel server = (ServerSocketChannel) key.channel();
                        SocketChannel clientn = server.accept();countclient++;
                        clientn.configureBlocking(false);
     clientn.register(selector, SelectionKey.OP_READ); 
                    } 
 else if (key.isWritable()) {
   SocketChannel clientn = (SocketChannel) key.channel();
   buffer.clear();
                            buffer.putDouble(25,Atan_joystickn);buffer.putDouble(25+8,j_Atan_joystickn);
                            buffer.putInt(0,boolmoven);
 
                        clientn.write(buffer);
                        System.out.println(n2 + " bytes written.");// Thread.sleep(155);
                        buffer.clear();
                       clientn.register(selector, SelectionKey.OP_READ); key.attachment();//key.interestOps(SelectionKey.OP_READ);
 }else if (key.isReadable()) {
 SocketChannel clientn = (SocketChannel) key.channel();
    buffer.clear();
    clientn.read(buffer);
Atan_joystickn=buffer.getDouble(25);j_Atan_joystickn=buffer.getDouble(25+8);
boolmoven=buffer.getInt(0);
buffer.flip();
    clientn.register(selector, SelectionKey.OP_WRITE);
                    }
.
.
.

SelectionKey key = channel.register(selector, SelectionKey.OP__ACCEPT, object);

private void handleAccept(SelectionKey key) throws IOException {
    Id ncl = new Id();
    SocketChannel sc = ((ServerSocketChannel) key.channel()).accept();
    String address = (new StringBuilder(sc.socket().getInetAddress().toString()))
                .append(":").append(sc.socket().getPort()).toString();
    ncl.addr = address;
    sc.configureBlocking(false);
    sc.register(selector, SelectionKey.OP_READ, ncl);
    clients++;
    broadcast(address+" Connected ("+clients+")\n");
}
 
private void broadcast(String msg) throws IOException {
    ByteBuffer msgBuf = ByteBuffer.wrap(msg.getBytes());
    int i = 0;
    for (SelectionKey key : selector.keys()) {
        if (key.isValid() && key.channel() instanceof SocketChannel) {
            SocketChannel sch = (SocketChannel) key.channel();
            //System.out.println(ncl.addr);
            System.out.println(sch);
            //Object object = key.attachment();
            //System.out.println(object);
            sch.write(msgBuf);
            msgBuf.rewind();
            i++;
        }
    }
}
 
class Id {
    public Object addr;
    public int user_id;
}

SelectionKey Skey=serverChannel.register(socketSelector, SelectionKey.OP_ACCEPT);
Skey.attach(0);

cceptor = new NioSocketAcceptor();
        acceptor.setReuseAddress(true);
//        acceptor.getFilterChain().addLast( "logger", new LoggingFilter() );
        TextLineCodecFactory t = new TextLineCodecFactory();
        t.setDecoderMaxLineLength(maxLength);
        t.setEncoderMaxLineLength(maxLength);
        acceptor.getFilterChain().addLast("codec", new ProtocolCodecFilter(t));
        acceptor.setHandler(proxyHandler);
        acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE, timeout);
        acceptor.bind(new InetSocketAddress(port));
        logger.info("Proxy acceptor has started on port " + port);