Android广播判断网络状态

package com.example.mjon.brocastreceiver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private IntentFilter intentFilter;
    private MyBrocastReceiver myBrocastReceiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        intentFilter = new IntentFilter();
        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        myBrocastReceiver = new MyBrocastReceiver();
        registerReceiver(myBrocastReceiver, intentFilter);
    }

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

    class MyBrocastReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
            if(networkInfo != null && networkInfo.isAvailable()){
                Toast.makeText(context, "Hava a Network", Toast.LENGTH_SHORT).show();
            }else{
                Toast.makeText(context, "Not a Network", Toast.LENGTH_SHORT).show();
            }
        }
    }
}