Android - detect whether there is an Internet connection available - Stack Overflow

The getActiveNetworkInfo() method of ConnectivityManager returns a NetworkInfo instance representing the first connected network interface it can find or null if none if the interfaces are connected. Checking if this method returns null should be enough to tell if an internet connection is available.

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.

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