Network broadcast receiver

NetworkActivity.java

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;

public class NetworkActivity extends AppCompatActivity {
    class NetworkBroadcastReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            //Handle network change
        }
    }

    private NetworkBroadcastReceiver networkBroadcastReceiver;

    @Override
    protected void onResume() {
        super.onResume();
        registerNetworkReceiver();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterNetworkReceiver();
    }

    private void registerNetworkReceiver() {
        if (networkBroadcastReceiver == null) {
            networkBroadcastReceiver = new NetworkBroadcastReceiver();
            IntentFilter intentFilter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
            registerReceiver(networkBroadcastReceiver, intentFilter);
        }
    }

    private void unregisterNetworkReceiver() {
        if (networkBroadcastReceiver != null) {
            unregisterReceiver(networkBroadcastReceiver);
            networkBroadcastReceiver = null;
        }
    }
}