find local network address in Android - including IP and NetMask? (ethernet not wifi)

Question

In Android emulator, the address (eth0) is 10.0.2.15/24

On a tablet that supports Ethernet, eth0 has a similar address: e.g. 192.168.0.2/24

How can I find it through existing Android APIs? (existing versions - prior to Android L preview!).

I know it can be done for WiFi via WifiManager.getDhcpInfo() - but I am interested in Ethernet - or even better a generic way.

Answer 1

Here's a method that will get the mask, AKA the network prefix length. The minimum API is 9 and the INTERNET permission is required. The address has a '/' prefix, but that can be easily removed by adding .toString.substring(1) or the like.

public void logLocalIpAddresses() {
    Enumeration<NetworkInterface> nwis;
    try {
        nwis = NetworkInterface.getNetworkInterfaces();
        while (nwis.hasMoreElements()) {

            NetworkInterface ni = nwis.nextElement();
            for (InterfaceAddress ia : ni.getInterfaceAddresses())

                Log.i(TAG, String.format("%s: %s/%d", 
                      ni.getDisplayName(), ia.getAddress(), ia.getNetworkPrefixLength()));
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}