Java Quickly check for network connection

Question

My issue is fairly straightforward. My program requires immediate notification if a network connection is lost. I'm using Java 5, so I'm unable to use the very handy features of NetworkInterface.

Currently I have two different methods of checking for a network connection:
(try..catches removed)

Method One:

URL url = new URL("http://www.google.com");
HttpURLConnection urlConnect = (HttpURLConnection) url.openConnection();
// trying to retrieve data from the source. If offline, this line will fail:
Object objData = urlConnect.getContent();
return true;

Method 2:

Socket socket = new Socket("www.google.com", 80);
netAccess = socket.isConnected();
socket.close();
return netAccess;

However, both of these methods block until a Timeout is reached before returning false. I need a method that will return immediately, but is compatible with Java 5.

Thanks!

EDIT: I forgot to mention that my program is reliant on IP addresses, not DNS names. So checking for an error when resolving a host is out...

2nd EDIT:

Figured out a final solution using NetworkInterface:

Enumeration<NetworkInterface> eni = NetworkInterface.getNetworkInterfaces();
        while(eni.hasMoreElements()) {
            Enumeration<InetAddress> eia = eni.nextElement().getInetAddresses();
            while(eia.hasMoreElements()) {
                InetAddress ia = eia.nextElement();
                if (!ia.isAnyLocalAddress() && !ia.isLoopbackAddress() && !ia.isSiteLocalAddress()) {
                    if (!ia.getHostName().equals(ia.getHostAddress()))
                        return true;
                }
            }
        }