How do I get IP_ADDRESS in IPV4 format

Question

I am trying to get the IP address of an device i.e using WIFI or 3G connection. I am getting the ip address in IPV6 format which is not understandable. I want in IPV4 format

Answer 1

You cannot assume that any device has just one network address. You also cannot assume that it will have any IPv4 - it may be IPv6 only, so your application will need to be able to handle both IPv4 and IPv6 address displays.

Typically, an Android phone has at least two interfaces that get assigned usable ip addresses, rmnet0 for the 3G data, which for IPv4 is often carrier-grade NATed and so cannot accept incoming socket connections, and may also have an IPv6 address; and wlan0 for the wifi, which will have whatever IPv4 and/or IPv6 address it can negotiate with the network it attaches to.

Some versions of Android will intentionally drop the (typically more expensive) rmnet0 link when it attaches to wifi - in an attempt to reduce 3G data usage. This behaviour is a problem when the wifi has attached to something that is a captive portal that requires a manual sign-in.

Answer 2

Following is a simple way to check either if it's IPv4 or IPv6:

InetAddress address = InetAddress.getByName(ip);
if (address instanceof Inet6Address) {
    // It's ipv6
} else if (address instanceof Inet4Address) {
    // It's ipv4
}

Answer 3

After trying many tricks.. finally I can get the IP address in IPV4 format.. Here is my code..

public String getLocalIpAddress() {
    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();
                System.out.println("ip1--:" + inetAddress);
                System.out.println("ip2--:" + inetAddress.getHostAddress());

      // for getting IPV4 format
      if (!inetAddress.isLoopbackAddress() && InetAddressUtils.isIPv4Address(ipv4 = inetAddress.getHostAddress())) {

                    String ip = inetAddress.getHostAddress().toString();
                    System.out.println("ip---::" + ip);
                    EditText tv = (EditText) findViewById(R.id.ipadd);
                    tv.setText(ip);
                    // return inetAddress.getHostAddress().toString();
                    return ip;
                }
            }
        }
    } catch (Exception ex) {
        Log.e("IP Address", ex.toString());
    }
    return null;
}

Added if condition as shown below

 /**This shows IPV4 format IP address*/
 if (!inetAddress.isLoopbackAddress() && InetAddressUtils.isIPv4Address(ipv4 = inetAddress.getHostAddress())){}

instead of this

 /**This shows IPV6 format IP address*/
 if (!inetAddress.isLoopbackAddress()){}

Many Thanks.. Rahul

An alternative for checking if the address is a version 4 address is:

if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address)

Answer 4

It seems there is a seperate class Inet4Address in the Java API for IPv4 addresses.