Address family not supported by protocol family: bind

Question

Over the past few days a number of users have reported connection issues with our application. We've been able to track the problem to this line of code:
ServerSocketChannel sc = ServerSocketChannel.open();
sc.socket().bind(new InetSocketAddress("localhost", 0)); <- error thrown
The following error is thrown:
java.net.SocketException: Address family not supported by protocol family: bind
sun.nio.ch.Net.bind(Native Method)
sun.nio.ch.ServerSocketChannelImpl.bind(Unknown Source)
sun.nio.ch.ServerSocketAdaptor.bind(Unknown Source)
sun.nio.ch.ServerSocketAdaptor.bind(Unknown Source)
I've read this is something to do with an IPv4 / IPv6 issue. But what I don't understand is that our users have had this working fine for months and we've never had any problems in the past, but within the last couple of days 10 people have contacted us, all with the same issue. We've not released any patches so we've not introduced the problem. Does anyone know what might have changed in the past few days? Did Microsoft release a patch to modify the IPv 4 / 6 protocols?
Apparently the issue might be resolved in Java7, but we have thousands of users, and rolling out a new version of Java is a big upheaval.
Any ideas???
BBB

Answer 1

It uses a JRE that is isolated for our application, so Java updates 'shouldn't' affect it. I have a sneaking suspicion that a Vista update may have changed something, but I can't be sure.
I'm working through the problem with one of our users, and I've changed the code from:
ServerSocketChannel sc = ServerSocketChannel.open();
sc.socket().bind(new InetSocketAddress("localhost", 0));To
ServerSocket sc = new ServerSocket();
sc.bind(new InetSocketAddress("localhost", 0));This works and I'm able to get an available port. However, later in the code it runs this section of code to connect the socket:
     void connect() throws IOException, InterruptedException {
          int retry;
          for (retry = 0; retry < MAX_RETRY; retry++) {
               try {
                    channel = SocketChannel.open();
                    channel.configureBlocking(false);
                    //connect to server
                    channel.connect(serverAddr);
                    //register events to listen
                    channel.register(selector, SelectionKey.OP_CONNECT);
                    while (!channel.isConnected()) {
                         if (selector.select(1) > 0) {
                              Set readyKeys = selector.selectedKeys();
                              Iterator i = readyKeys.iterator();
                              while (i.hasNext()) {
                                   SelectionKey key = (SelectionKey) i.next();
                                   i.remove();
                                   SocketChannel keyChannel = (SocketChannel) key
                                             .channel();
                                   if (key.isConnectable()) {
                                        if (keyChannel.isConnectionPending()) {
                                             keyChannel.finishConnect();
                                        break;
                    break;
               } catch (Exception e) {
                    channel.close();
                    channel = null;
                    try {
                         Thread.sleep(150);
                    } catch (Exception ex) {
          if (retry == MAX_RETRY) {
               throw new InterruptedException("Maximum retry number reached!");
          channel.register(selector, SelectionKey.OP_READ);
     }It's now falling over on this line:
channel.connect(serverAddr);
java.net.SocketException: Address family not supported by protocol family: connect
serverAddr is a InetSocketAddress, channel is a SocketChannel, which appears not to be supported on the machine that are having these connection issues.
I'll be honest, I have little or no experience of implementing Sockets, and since I can't replicate the actual problem that our users are having it makes it even hard to fix it or try to code a workaround. The code above is from an OpenSource project, i.e. it's not something I wrote. In other words, I'm kinda up the 'proverbial creek'!
Could anybody be kind enough to steer me in the right direction for a workaround that doesn't use a SocketChannel? It really would be appreciated!
BBB