Android每日通知无法正常运行

我想每天早上9点从我的应用程序显示通知。

因此，我正在使用通知管理器，警报管理器，BroadcastReciever和服务来实现这一点。

但是我有一个问题，因为通知是随机显示的。当我第一次启动该应用程序并设置时间时，它工作正常，但后来该应用程序启动并在随机时间显示通知。

我该如何解决？

这是我的代码：

主要活动

@Override
protected void onStart() {
    super.onStart();
    setAlarm();
}

public void setAlarm(){


    Calendar calendar = Calendar.getInstance();
    Calendar now = Calendar.getInstance();


    calendar.set(Calendar.HOUR_OF_DAY, 15);
    calendar.set(Calendar.MINUTE, 43);
    calendar.set(Calendar.SECOND, 0);

    if(calendar.getTime().after(now.getTime())) {
        alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);

        alarmIntent = new Intent(MainActivity.this, HoroscopeNotification.class);
        pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);


        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pendingIntent);        }

 }

HoroscopNotification（广播接收者）

public class HoroscopeNotification extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent arg1) {
        showNotification(context);
    }

    private void showNotification(Context context) {
        Intent service1 = new Intent(context, AlarmService.class);
        context.startService(service1);
    }
}

报警服务

public class AlarmService extends Service {
    private static final int NOTIFICATION_ID = 1;
    private NotificationManager notificationManager;
    private PendingIntent pendingIntent;

    @Override
    public IBinder onBind(Intent arg0)
    {
         return null;
    }

    @SuppressWarnings("static-access")
    @Override
    public void onStart(Intent intent, int startId)
    {
        super.onStart(intent, startId);
        Context context = this.getApplicationContext();
        notificationManager = (NotificationManager)context.getSystemService(context.NOTIFICATION_SERVICE);
        Intent mIntent = new Intent(this, MainActivity.class);
        pendingIntent = PendingIntent.getActivity(context, 0, mIntent, PendingIntent.FLAG_CANCEL_CURRENT);
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        builder.setContentTitle("Horoskop");
        builder.setContentText("Pročitajte današnji horoskop");
        builder.setSmallIcon(R.drawable.ic_bik);
        builder.setAutoCancel(true);
        builder.setContentIntent(pendingIntent);

        notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
        notificationManager.notify(NOTIFICATION_ID, builder.build());
    }
}