Android, Java: Multicast check

gistfile1.txt

/** 
     * Ensures that the caller receives an usable multicast socket. 
     * In case the network configuration does not have a default gateway 
     * set, the multicast socket might not work. This is the case when 
     * the device is connected to a Wireless Direct printer. In that 
     * cases, force a network interface into the socket. 
     * 
     * @return A ready-to-use multicast socket. 
     */ 
    public static MulticastSocket createMulticastSocket(Context context)
            throws UnknownHostException, SocketException, IOException { 
        MulticastSocket multicastSocket = new MulticastSocket();
 
        if (connectedToEthernet(context)) {
            NetworkInterface netIf = NetworkInterface.getByName("eth0");
            if (netIf != null)
                multicastSocket.setNetworkInterface(netIf);
        } 
        else if (isWirelessDirect(context)) {
            WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
            WifiInfo wifiInfo = wifiManager.getConnectionInfo();
            int intaddr = wifiInfo.getIpAddress();
            byte[] byteaddr = new byte[] {
                    (byte) (intaddr & 0xff),
                    (byte) (intaddr >> 8 & 0xff),
                    (byte) (intaddr >> 16 & 0xff),
                    (byte) (intaddr >> 24 & 0xff)};
            InetAddress addr = InetAddress.getByAddress(byteaddr);
            NetworkInterface netIf = NetworkInterface.getByInetAddress(addr);
 
            multicastSocket.setNetworkInterface(netIf);
        } 
        multicastSocket.setTimeToLive(MULTICAST_TTL);
        return multicastSocket;
    } 
 
    public static boolean isWirelessDirect(Context context) {
        ConnectivityManager connManager =
                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = connManager.getActiveNetworkInfo();
 
        if (netInfo != null && netInfo.isConnected() && (netInfo.getType() == ConnectivityManager.TYPE_WIFI)) {
            WifiManager wifiManager =
                    (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
            DhcpInfo dhcpInfo = wifiManager.getDhcpInfo();
 
            if ((dhcpInfo != null) && (dhcpInfo.gateway == 0)) {
                Log.d(TAG, "isWirelessDirect: probably wireless direct.");
                return true; 
            } 
        } 
        return false; 
    }