Do i need to check whether the phone is in offline mode in every time a new activity is called?

I have written a code to check whether the phone is currently online or not. But my question is do i need to check whether the phone is in offline mode in every time a new activity is called? if yes then what is the better way to code that?

The code to check whether phone is online or offline is like this:

    private boolean isOnline() {
      ConnectivityManager cm = (ConnectivityManager)getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
      NetworkInfo nwrkInfo = cm.getActiveNetworkInfo();
      if (nwrkInfo != null && nwrkInfo.isConnectedOrConnecting()) {
          return true;
      }
      return false;
}

The above code will return true when the phone is online otherwise false. Is there any oops technique so that i can access this method from other activity?