...
IntentFilter filter = new IntentFilter();
filter.addAction("Broadcast.MqttServiceSend");//说明监听什么样的广播
registerReceiver(MainActivityReceiver, filter);//注册广播同时传入接收函数
...

/*该类的广播接收程序*/
private BroadcastReceiver MainActivityReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        //收到广播后执行的动作
    }
};

Intent intent = new Intent();
intent.setAction("Broadcast.MqttServiceSend");//这两句可以合体为Intent intent = new Intent("Broadcast.MqttServiceSend");
intent.putExtra("MqttServiceSend",arg0+";;"+arg1.toString());//puExtra遵循键值对的写法，可让广播携带数据
sendBroadcast(intent);//发送广播