networkInfo.isConnected() method return true even there is no internet?

Question

i develop this app , in the main activity i check the internet connection as the following :

ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();

    if (networkInfo != null && networkInfo.isConnected()) {
        LoaderManager loaderManager = getSupportLoaderManager();
        loaderManager.initLoader(1, null, this);

    }

when i go to HOURLY activity i check the internet in the same way like above on the onCreate() method.

my question when i open the main activity i disconnect the internet and go to HOURLY activity to handle "no internet exception" but networkInfo.isConnected() in HOURLY activity return true why the internet still connect???

Answer 1

I don't know what you're intended to do with above code but I am sure this will work.

The getActiveNetworkInfo() method of ConnectivityManager returns a NetworkInfo instance representing the first connected network interface it can find or null if none of the interfaces are connected. Checking if this method returns null should be enough to tell if an internet connection is available or not.

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

You will also need:

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

in your android manifest.

Note that having an active network interface doesn't guarantee that a particular networked service is available. Network issues, server downtime, low signal, captive portals, content filters and the like can all prevent your app from reaching a server. For instance you can't tell for sure if your app can reach Twitter until you receive a valid response from the Twitter service.