Detect if Android device has Internet connection

Question

I need to tell if my device has Internet connection or not. I found many answers like:

private boolean isNetworkAvailable() {
    ConnectivityManager connectivityManager 
         = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    return activeNetworkInfo != null;
}

^{(Taken from Detect whether there is an Internet connection available on Android.)}

But this is not right, for example if I'm connected to a wireless network which doesn't have Internet access, this method will return true… Is there a way to tell if the device has Internet connection and not if it is only connected to something?

Answer 1

Based on the accepted answers, I have built this class with a listener so you can use it in the main thread:

First: InterntCheck class which checks for internet connection in the background then call a listener method with the result.

public class InternetCheck extends AsyncTask<Void, Void, Void> {


    private Activity activity;
    private InternetCheckListener listener;

    public InternetCheck(Activity x){

        activity= x;

    }

    @Override
    protected Void doInBackground(Void... params) {


        boolean b = hasInternetAccess();
        listener.onComplete(b);

        return null;
    }


    public void isInternetConnectionAvailable(InternetCheckListener x){
        listener=x;
        execute();
    }

    private boolean isNetworkAvailable() {
        ConnectivityManager connectivityManager = (ConnectivityManager) activity.getSystemService(CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null;
    }
    private boolean hasInternetAccess() {
        if (isNetworkAvailable()) {
            try {
                HttpURLConnection urlc = (HttpURLConnection) (new URL("http://clients3.google.com/generate_204").openConnection());
                urlc.setRequestProperty("User-Agent", "Android");
                urlc.setRequestProperty("Connection", "close");
                urlc.setConnectTimeout(1500);
                urlc.connect();
                return (urlc.getResponseCode() == 204 &&
                        urlc.getContentLength() == 0);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            Log.d("TAG", "No network available!");
        }
        return false;
    }

    public interface InternetCheckListener{
        void onComplete(boolean connected);
    }

}

Second: instantiate an instance of the class in the main thread and wait for the response (if you have worked with Firebase api for android before this should be familiar to you!).

new InternetCheck(activity).isInternetConnectionAvailable(new InternetCheck.InternetCheckListener() {

        @Override
        public void onComplete(boolean connected) {
           //proceed!
        }
    });

Now inside onComplete method you will get whether the device is connected to the internet or not.

Answer 2

I have modified THelper's answer slightly, to use a known hack that Android already uses to check if the connected WiFi network has Internet access. This is a lot more efficient over grabbing the entire Google home page. See here and here for more info.

public static boolean hasInternetAccess(Context context) {
    if (isNetworkAvailable(context)) {
        try {
            HttpURLConnection urlc = (HttpURLConnection) 
                (new URL("http://clients3.google.com/generate_204")
                .openConnection());
            urlc.setRequestProperty("User-Agent", "Android");
            urlc.setRequestProperty("Connection", "close");
            urlc.setConnectTimeout(1500); 
            urlc.connect();
            return (urlc.getResponseCode() == 204 &&
                        urlc.getContentLength() == 0);
        } catch (IOException e) {
            Log.e(TAG, "Error checking internet connection", e);
        }
    } else {
        Log.d(TAG, "No network available!");
    }
    return false;
}

Answer 3

If you're targeting Lollipop or higher it's possible to use the new NetworkCapabilities class, i.e:

public static boolean hasInternetConnection(final Context context) {
    final ConnectivityManager connectivityManager = (ConnectivityManager)context.
            getSystemService(Context.CONNECTIVITY_SERVICE);

    final Network network = connectivityManager.getActiveNetwork();
    final NetworkCapabilities capabilities = connectivityManager
            .getNetworkCapabilities(network);

    return capabilities != null
            && capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED);
}