How to listen for Connectivity change in android?

This is a class I wrote for myself. It listens for connectivity changes and can launch callbacks when the internet connection goes up or down.

To use it, create a new instance in your onCreate, call bind(this) in onResume and unbind(this) in onPause.

You can then do two things: call hasConnection() at any time to check if there is an Internet connection or implementOnNetworkAvailableListener in order to get notified when the network state changes.

You'll need the following permissions:

• android.permission.INTERNET
• android.permission.ACCESS_NETWORK_STATE

public class ConnectivityReceiver extends BroadcastReceiver {

    

    public static interface OnNetworkAvailableListener {

        public void onNetworkAvailable();

        public void onNetworkUnavailable();

    }

    

    private final ConnectivityManager connectivityManager;

    private OnNetworkAvailableListener onNetworkAvailableListener;

    private boolean connection = false;

    

    public ConnectivityReceiver(Context context) {

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

        checkConnectionOnDemand();

    }

    

    public void bind(Context context) {

        IntentFilter filter = new IntentFilter();

        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);

        context.registerReceiver(this, filter);

        checkConnectionOnDemand();

    }

    

    public void unbind(Context context) {

        context.unregisterReceiver(this);

    }

    private void checkConnectionOnDemand() {

        final NetworkInfo info = connectivityManager.getActiveNetworkInfo();

        if (info == null || info.getState() != State.CONNECTED) {

            if (connection == true) {

                connection = false;

                if (onNetworkAvailableListener != null) onNetworkAvailableListener.onNetworkUnavailable();

            }

        }

        else {

            if (connection == false) {

                connection = true;

                if (onNetworkAvailableListener != null) onNetworkAvailableListener.onNetworkAvailable();

            }

        }

    }

    

    @Override

    public void onReceive(Context context, Intent intent) {

        if (connection == true && intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false)) {

            connection = false;

            if (onNetworkAvailableListener != null) {

                onNetworkAvailableListener.onNetworkUnavailable();

            }

        }

        else if (connection == false && !intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false)) {

            connection = true;

            if (onNetworkAvailableListener != null) {

                onNetworkAvailableListener.onNetworkAvailable();

            }

        }

    }

    

    public boolean hasConnection() {

        return connection;

    }

    

    public void setOnNetworkAvailableListener(OnNetworkAvailableListener listener) {

        this.onNetworkAvailableListener = listener;

    }

}