notify while network is available or not

   <receiver
        android:name=".receivers.NetworkChangeReceiver"
        android:label="NetworkChangeReceiver">
        <intent-filter>
            <action
                android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            <action
                android:name="android.net.wifi.WIFI_STATE_CHANGED" />
        </intent-filter>
    </receiver>

public class NetworkChangeReceiver extends BroadcastReceiver{

   @Override
   public void onReceive(Context context, Intent intent) {
       ConnectivityManager cm=(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
       if(cm.getActiveNetworkInfo()!=null&&cm.getActiveNetworkInfo().isConnected()){
           //Send a broadcast to your service or activity that you have network
           //...
       }else{
           LOG.i("Network UNAVAILABLE");
       }
   }

}