check ethernet connection periodically android

Question

I'm trying to periodically check the network connection. However, this is for a Chinese Android Mini PC, not a tablet or smartphone. I'm using an ethernet to usb adapter instead of Wi-Fi. First I used a broadcastreceiver class:

public class NetworkStateReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getExtras() != null) {
            @SuppressWarnings("deprecation")
            NetworkInfo eni = (NetworkInfo) intent.getExtras().get(
                    ConnectivityManager.EXTRA_NETWORK_INFO);

            if (eni != null && eni.getState() == NetworkInfo.State.CONNECTED) {
                Log.d(TAG, "Network " + eni.getTypeName() + " connected.");
            }
        }
        if (intent.getExtras().getBoolean(
                ConnectivityManager.EXTRA_NO_CONNECTIVITY, Boolean.FALSE)) {
            Log.d(TAG, "There's no network connectivity.");
        }
    }
}

This works perfectly for Wi-Fi and mobile. However, for ethernet, there are complications. When I connect the ethernet to usb adapter, it thinks it already has ETHERNET connection, whether the ethernet cable is connected or not. Only when removing the adapter, it knows the ethernet connection was removed.

I tried using a socket, and this kind of works:

    private static boolean checkSocket(String host, int port) {
        Socket socket = null;
        boolean reachable = false;
        try {
            socket = new Socket(InetAddress.getByName(host), port);
            reachable = true;
        } catch (UnknownHostException e) {
        } catch (IOException e) {
        } finally {
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                }
            }
        }
        return reachable;
    }

When there is a connection, it works perfectly and fast. When the connection is lost, it takes way too long for the program to know it has. I need this solution, but it should know way faster that the ethernet connection has been lost. Also, this relies on Exceptions, which I'm not fond of at all.

Lastly I tried a simple ICMP message:

    try {
        InetAddress address = InetAddress.getByName(host);
        if (address.isReachable(timeout)) {
            return true;
        }
    } catch (UnknownHostException e) {
    } catch (IOException e) {
    }
    return false;

This should work, right? Unfortunately, it doesn't. Until now, I've always received a false when executing this code.

What am I doing wrong and what is the correct way to do this?

EDIT 1

I have now tried this solution, which works and doesn't work. It's funny and annoying, as I'm checking this in the onResume(). After a few correct tries, it suddenly stops. I have no idea why though.

    boolean reachable = false;
    try {
        Process p1 = java.lang.Runtime.getRuntime().exec("ping -c 1 " + host);
        int retValue = p1.waitFor();
        reachable = (retValue == 0);
        Log.d(TAG, String.valueOf(reachable));
        p1.destroy();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return reachable;

Answer 1

Try connecting to ip addres, not resolving dns as you do

ADD: Try using ConnectivityManager.getActiveNetworkInfo then

((ConnectivityManager) Context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo().isConnected()