Check whether there is an Internet connection available on Android

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

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

References
https://stackoverflow.com/questions/4238921/detect-whether-there-is-an-internet-connection-available-on-android