如何访问Java中每个NetworkInterface的特定于连接的DNS后缀？

String findDnsSuffix() {

// First I get the hosts name
// This one never contains the DNS suffix (Don\'t know if that is the case for all VM vendors)
String hostName = InetAddress.getLocalHost().getHostName().toLowerCase();

// Alsways convert host names to lower case. Host names are 
// case insensitive and I want to simplify comparison.

// Then I iterate over all network adapters that might be of interest
Enumeration<NetworkInterface> ifs = NetworkInterface.getNetworkInterfaces();

if (ifs == null) return \"\"; // Might be null

for (NetworkInterface iF : Collections.list(ifs)) { // convert enumeration to list.
    if (!iF.isUp()) continue;

    for (InetAddress address : Collections.list(iF.getInetAddresses())) {
        if (address.isMulticastAddress()) continue;

        // This name typically contains the DNS suffix. Again, at least on Oracle JDK
        String name = address.getHostName().toLowerCase();

        if (name.startsWith(hostName)) {
            String dnsSuffix = name.substring(hostName.length());
            if (dnsSuffix.startsWith(\".\")) return dnsSuffix;
        }
    }
}

return \"\";
}