Get Android WiFi “net.hostname” from code

Question

When an Android device connects to a wifi AP, it identifies itself with a name like:

android_cc1dec12345e6054

How can that string be obtained from within an Andr

Answer 1

Use the NetworkInterface object to enumerate the interfaces and get the canonical host name from the interfaces' InetAddress. Since you want the wifi name, as a shortcut you can query for wlan0 directly and if that fails you can enumerate them all like this:

import android.test.InstrumentationTestCase;
import android.util.Log;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Enumeration;

public class NetworkInterfaceTest extends InstrumentationTestCase {
    private static final String TAG = NetworkInterfaceTest.class.getSimpleName();
    public void testNetworkName() throws Exception {
        Enumeration it_ni = NetworkInterface.getNetworkInterfaces();
        while (it_ni.hasMoreElements()) {
            NetworkInterface ni = it_ni.nextElement();
            Enumeration it_ia = ni.getInetAddresses();
            if (it_ia.hasMoreElements()) {
                Log.i(TAG, "++ NI:   " + ni.getDisplayName());
                while (it_ia.hasMoreElements()) {
                    InetAddress ia = it_ia.nextElement();
                    Log.i(TAG, "-- IA:   " + ia.getCanonicalHostName());
                    Log.i(TAG, "-- host: " + ia.getHostAddress());
                }
            }
        }
    }
}

That will give you an output like this:

TestRunner﹕ started: testNetworkName
++ NI:   lo
-- IA:   ::1%1
-- host: ::1%1
-- IA:   localhost
-- host: 127.0.0.1
++ NI:   p2p0
-- IA:   fe80::1234:1234:1234:1234%p2p0
-- host: fe80::1234:1234:1234:1234%p2p0
++ NI:   wlan0
-- IA:   fe80::1234:1234:1234:1234%wlan0
-- host: fe80::1234:1234:1234:1234%wlan0
-- IA:   android-1234567812345678   <--- right here
-- host: 192.168.1.234

Tip: if InetAddress.getCanonicalHostName().equals(InetAddress.getHostAddress()) you can ignore it as it's not a "real" name.