Some applications need Internet connectivity to run it. That's why Developer needs to check whether Internet connection is there or not? If yes, then one can do task otherwise need to alert user to connect his Smart Phone or Tablet to Internet.
I searched and found this code be useful to check Internet Connectivity.

/**

* This method will check whether Phone/Tablet has Internet connection or
* not
*
* @param context
* : Context
* @return <b>True</b> : If Internet is Connected<br>
* <b>False</b> : If Internet is not Connected
*/
public static boolean checkNetworkConnectivity(Context context) {
ConnectivityManager connMgr = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
/**
* check for Wi-Fi and mobile Internet connection
*/
if (connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnected()
|| connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)
.isConnected()) {
/**
* Internet connected
*/
return true;
}
/**
* no connection
*/
return false;
}