code: public static String getHostnameOrAddress() {
          final InetAddress addr = m_localAddressSupplier.get();
          if (addr == null) return "";
          return ReverseDNSCache.hostnameOrAddress(addr);
      }
docs: Return the local hostname, if it's resolvable.  If not,
  return the IPv4 address on the first interface we find, if it exists.
  If not, returns whatever address exists on the first interface.
  @return the String representation of some valid host or IP address,
  if we can find one; the empty string otherwise