您不需要像目前提供的解决方案那样添加权限。以字符串形式下载此网站:

http://www.ip-api.com/json

or

http://www.telize.com/geoip

下载一个网站作为字符串可以用java代码完成:

http://www.itcuties.com/java/read-url-to-string/

像这样解析JSON对象:

https://stackoverflow.com/a/18998203/1987258

json属性“query”或“ip”包含ip地址。

在Kotlin中，没有Formatter

private fun getIPAddress(useIPv4 : Boolean): String {
    try {
        var interfaces = Collections.list(NetworkInterface.getNetworkInterfaces())
        for (intf in interfaces) {
            var addrs = Collections.list(intf.getInetAddresses());
            for (addr in addrs) {
                if (!addr.isLoopbackAddress()) {
                    var sAddr = addr.getHostAddress();
                    var isIPv4: Boolean
                    isIPv4 = sAddr.indexOf(':')<0
                    if (useIPv4) {
                        if (isIPv4)
                            return sAddr;
                    } else {
                        if (!isIPv4) {
                            var delim = sAddr.indexOf('%') // drop ip6 zone suffix
                            if (delim < 0) {
                                return sAddr.toUpperCase()
                            }
                            else {
                                return sAddr.substring(0, delim).toUpperCase()
                            }
                        }
                    }
                }
            }
        }
    } catch (e: java.lang.Exception) { }
    return ""
}

编译一些想法，以更好的kotlin解决方案从WifiManager获得wifi ip:

private fun getWifiIp(context: Context): String? {
  return context.getSystemService<WifiManager>().let {
     when {
      it == null -> "No wifi available"
      !it.isWifiEnabled -> "Wifi is disabled"
      it.connectionInfo == null -> "Wifi not connected"
      else -> {
        val ip = it.connectionInfo.ipAddress
        ((ip and 0xFF).toString() + "." + (ip shr 8 and 0xFF) + "." + (ip shr 16 and 0xFF) + "." + (ip shr 24 and 0xFF))
      }
    }
  }
}

或者，您可以通过NetworkInterface获取ip4环回设备的ip地址:

fun getNetworkIp4LoopbackIps(): Map<String, String> = try {
  NetworkInterface.getNetworkInterfaces()
    .asSequence()
    .associate { it.displayName to it.ip4LoopbackIps() }
    .filterValues { it.isNotEmpty() }
} catch (ex: Exception) {
  emptyMap()
}

private fun NetworkInterface.ip4LoopbackIps() =
  inetAddresses.asSequence()
    .filter { !it.isLoopbackAddress && it is Inet4Address }
    .map { it.hostAddress }
    .filter { it.isNotEmpty() }
    .joinToString()

方法getDeviceIpAddress返回设备的ip地址，如果连接了wifi接口，则首选wifi接口地址。

  @NonNull
    private String getDeviceIpAddress() {
        String actualConnectedToNetwork = null;
        ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connManager != null) {
            NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
            if (mWifi.isConnected()) {
                actualConnectedToNetwork = getWifiIp();
            }
        }
        if (TextUtils.isEmpty(actualConnectedToNetwork)) {
            actualConnectedToNetwork = getNetworkInterfaceIpAddress();
        }
        if (TextUtils.isEmpty(actualConnectedToNetwork)) {
            actualConnectedToNetwork = "127.0.0.1";
        }
        return actualConnectedToNetwork;
    }

    @Nullable
    private String getWifiIp() {
        final WifiManager mWifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        if (mWifiManager != null && mWifiManager.isWifiEnabled()) {
            int ip = mWifiManager.getConnectionInfo().getIpAddress();
            return (ip & 0xFF) + "." + ((ip >> 8) & 0xFF) + "." + ((ip >> 16) & 0xFF) + "."
                    + ((ip >> 24) & 0xFF);
        }
        return null;
    }


    @Nullable
    public String getNetworkInterfaceIpAddress() {
        try {
            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements(); ) {
                NetworkInterface networkInterface = en.nextElement();
                for (Enumeration<InetAddress> enumIpAddr = networkInterface.getInetAddresses(); enumIpAddr.hasMoreElements(); ) {
                    InetAddress inetAddress = enumIpAddr.nextElement();
                    if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address) {
                        String host = inetAddress.getHostAddress();
                        if (!TextUtils.isEmpty(host)) {
                            return host;
                        }
                    }
                }

            }
        } catch (Exception ex) {
            Log.e("IP Address", "getLocalIpAddress", ex);
        }
        return null;
    }

在AndroidManifest.xml中声明ACCESS_WIFI_STATE权限:

<uses-permission
    android:name="android.permission.ACCESS_WIFI_STATE"/>

可以通过WifiManager获取IP地址:

Context context = requireContext().getApplicationContext();
WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
String ip = Formatter.formatIpAddress(wm.getConnectionInfo().getIpAddress());

public static String getdeviceIpAddress() {
    try {
        for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
            NetworkInterface intf = en.nextElement();
            for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
                InetAddress inetAddress = enumIpAddr.nextElement();
                if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address) {
                    return inetAddress.getHostAddress();
                }
            }
        }
    } catch (SocketException ex) {
        ex.printStackTrace();
    }
    return null;
}