android listen to network change

1ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
2    @Override
3    public void onAvailable(Network network) {
4        // network available
5    }
6
7    @Override
8    public void onLost(Network network) {
9        // network unavailable
10    }
11};
12
13ConnectivityManager connectivityManager =
14        (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
15
16if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
17    connectivityManager.registerDefaultNetworkCallback(networkCallback);
18} else {
19    NetworkRequest request = new NetworkRequest.Builder()
20            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET).build();
21    connectivityManager.registerNetworkCallback(request, networkCallback);
22}
23

1val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
2connectivityManager?.let {
3    it.registerDefaultNetworkCallback(object : ConnectivityManager.NetworkCallback() {
4        override fun onAvailable(network: Network) {
5            //take action when network connection is gained
6        }
7        override fun onLost(network: Network?) {
8            //take action when network connection is lost
9        }
10    })
11}
12