Non-blocking server

Question

Hi there,
I've got a problem with the NIO package: I'm trying to make a simple webserver, just to get familiar with SocketChannel, ServerSocketChannel, Selector, Buffer's and so on. My problem is that my server can only receive one single request, then it ignores the rest. This is the code:
    private void setupServer() throws IOException
        selector = Selector.open();
        serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.socket().bind(new InetSocketAddress(80));
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.register(selector,SelectionKey.OP_ACCEPT);
    public synchronized void start() {
        setPriority(Thread.MIN_PRIORITY); //If I don't set this to min, it consumes a LOT of resources...
        try {
            setupServer();
        } catch (IOException e) {
            throw new RuntimeException("Failed to start server.",e);
        super.start();
    public void run() {
        while(true)
            try {
                while(selector.select() > 0)
                    //This code will run ONCE
                    Iterator i = selector.keys().iterator();
                    while(i.hasNext())
                        SelectionKey key = (SelectionKey)i.next();
                        i.remove();
                        if(key.isAcceptable())
                            ServerSocketChannel serverChannel = (ServerSocketChannel)key.channel();
                            SocketChannel channel = serverChannel.accept();
                            //Register the channel somewhere, read from it and close it
            } catch (IOException e) {
                throw new RuntimeException("Server Crashed!",e);
    }What have I done wrong? It is something wrong, since it only receive one request... Please help me...
Nille

Answer 1

You might try changing the while condition to selector.select()>=0.
If you call wakeup or something in other parts of the code it will cause the select call to return 0 which in your case will cause the server to stop.