Verificar conexión a internet

Fuente:

https://stackoverflow.com/questions/32547006/connectivitymanager-getnetworkinfoint-deprecated

ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
if (activeNetwork != null) { 
    // connected to the internet
    if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
        // connected to wifi
    } else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
        // connected to mobile data
    }
} else {
    // not connected to the internet
}