如下为dubbo的代码

    2. private static Optional<InetAddress> toValidAddress(InetAddress address) {
    3.     if (address instanceof Inet6Address) {
    4.         Inet6Address v6Address = (Inet6Address) address;
    5.         if (isPreferIPV6Address()) {
    6.             return Optional.ofNullable(normalizeV6Address(v6Address));
    7.         }
    8.     }
    9.     if (isValidV4Address(address)) {
    10.         return Optional.of(address);
    11.     }
    12.     return Optional.empty();
    13. }
    15. private static InetAddress getLocalAddress0() {
    16.     InetAddress localAddress = null;
    17.     try {
    18.         localAddress = InetAddress.getLocalHost();
    19.         Optional<InetAddress> addressOp = toValidAddress(localAddress);
    20.         if (addressOp.isPresent()) {
    21.             return addressOp.get();
    22.         }
    23.     } catch (Throwable e) {
    24.         logger.warn(e);
    25.     }
    27.     try {
    28.         Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
    29.         if (null == interfaces) {
    30.             return localAddress;
    31.         }
    32.         while (interfaces.hasMoreElements()) {
    33.             try {
    34.                 NetworkInterface network = interfaces.nextElement();
    35.                 if (network.isLoopback() || network.isVirtual() || !network.isUp()) {
    36.                     continue;
    37.                 }
    38.                 Enumeration<InetAddress> addresses = network.getInetAddresses();
    39.                 while (addresses.hasMoreElements()) {
    40.                     try {
    41.                         Optional<InetAddress> addressOp = toValidAddress(addresses.nextElement());
    42.                         if (addressOp.isPresent()) {
    43.                             try {
    44.                                 if (addressOp.get().isReachable(100)) {
    45.                                     return addressOp.get();
    46.                                 }
    47.                             } catch (IOException e) {
    48.                                 // ignore
    49.                             }
    50.                         }
    51.                     } catch (Throwable e) {
    52.                         logger.warn(e);
    53.                     }
    54.                 }
    55.             } catch (Throwable e) {
    56.                 logger.warn(e);
    57.             }
    58.         }
    59.     } catch (Throwable e) {
    60.         logger.warn(e);
    61.     }
    62.     return localAddress;
    63. }
    65. public static String getHostName(String address) {
    66.     try {
    67.         int i = address.indexOf(':');
    68.         if (i > -1) {
    69.             address = address.substring(0, i);
    70.         }
    71.         String hostname = HOST_NAME_CACHE.get(address);
    72.         if (hostname != null && hostname.length() > 0) {
    73.             return hostname;
    74.         }
    75.         InetAddress inetAddress = InetAddress.getByName(address);
    76.         if (inetAddress != null) {
    77.             hostname = inetAddress.getHostName();
    78.             HOST_NAME_CACHE.put(address, hostname);
    79.             return hostname;
    80.         }
    81.     } catch (Throwable e) {
    82.         // ignore
    83.     }
    84.     return address;
    85. }