运行固定时间后每天一个方法

Question

我的应用程序中有一个功能，用户可以 select 在他想要从应用程序获取通知的时间。在这种情况下，我以这种格式 12:00 AM 从用户那里获取输入。我写了一个在我的应用程序中创建通知的方法，它工作正常，但我想每天在用户 selected 时间调用该方法。此外，如果应用程序完全被破坏，甚至运行在后台，此方法是否会在每天用户 selected 时间调用？

String user_time=tinyDB.getString("app_check_time"); // This is user selected time e.g, 12:00 PM
Calendar calendar = Calendar.getInstance();
Date date1 = null;
try {
    date1=new SimpleDateFormat("h:m a").parse(user_time);
} catch (ParseException e) {
    e.printStackTrace();
}
calendar.set(Calendar.HOUR_OF_DAY, date1.getHours());
calendar.set(Calendar.MINUTE, date1.getMinutes());
Date time = calendar.getTime();
System.out.println("hourr  "+time);
timer = new Timer();
timer.schedule(new createNotification(), time);

Answer 1

您是否考虑过使用像 Quartz Scheduler 这样的东西？该库有一种机制，可以使用类似 cron 的表达式（查看 CronScheduleBuilder）在每天设定的时间段将任务安排到运行。

一些示例代码（未测试）：

public class GetDatabaseJob implements InterruptableJob
{
    public void execute(JobExecutionContext arg0) throws JobExecutionException
    {
        getFromDatabase();
    }
}

public class Example
{
    public static void main(String[] args)
    {
        JobDetails job = JobBuilder.newJob(GetDatabaseJob.class);

        // Schedule to run at 5 AM every day
        ScheduleBuilder scheduleBuilder = 
                CronScheduleBuilder.cronSchedule("0 0 5 * * ?");
        Trigger trigger = TriggerBuilder.newTrigger().
                withSchedule(scheduleBuilder).build();

        Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
        scheduler.scheduleJob(job, trigger);

        scheduler.start();

} }

前期的工作有点多，您可能需要重写您的作业执行代码，但它应该让您更好地控制您希望作业如何运行。如果您需要，更改时间表也会更容易

Answer 2

您可以为此使用 WorkManager。是的，它会运行即使你的应用程序完全死了。

来自 Android Docs：

WorkManager is a library used to enqueue deferrable work that is guaranteed to execute sometime after its Constraints are met.

您可以在此处查看指南https://developer.android.com/topic/libraries/architecture/workmanager

The WorkManager API makes it easy to schedule deferrable, asynchronous tasks that are expected to run even if the app exits or device restarts.

希望对您有所帮助！

Answer 3

为此任务创建一个长运行服务

Intent intent = new Intent(this, ReminderService.class);
startService(intent);

创建扩展服务的提醒服务

public class ReminderService extends Service {

    @Override
    public void onCreate() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(calendar.get(Calendar.YEAR),
                calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH),
                6,
                0,
                0);
        setAlarm(calendar.getTimeInMillis());
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // If we get killed, after returning from here, restart
        return START_STICKY;
    }

public void setAlarm(long timeInMillis) {
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(this, ReminderReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this,
                0, intent, 0);
        if (alarmManager != null) {
            alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, timeInMillis,
                    2 * 60 * 1000 , pendingIntent); //AlarmManager.INTERVAL_DAY //2 * 60 * 1000 (2 minutes)
        }
    }
}

创建扩展 BroadcastReceiver 的 ReminderReceiver

public class ReminderReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        //do task to show notification
ShowNotification showNotification = new ShowNotification(context);
                showNotification.showNotification("Method called");

    }
}

创建 ShowNotification class

public class ShowNotification {

    private static final int NOTIFICATION = 0;
    private static final String NOTIFICATION_CHANNEL_ID = "100";
    private Context context;
    private NotificationManager notificationManager;
    private ConnectivityManager conManager;

    public ShowNotification(Context context) {
        this.context = context;
        if (notificationManager == null) {
            notificationManager = (NotificationManager) context
                    .getSystemService(Context.NOTIFICATION_SERVICE);
        }

        if (conManager == null) {
            conManager = (ConnectivityManager) context
                    .getSystemService(Context.CONNECTIVITY_SERVICE);
        }
    }

    /**
     * Show a notification while this service is running.
     *
     * @param key
     */
    void showNotification(String key) {
        String NOTIFICATION_CHANNEL_NAME = "NOTIFICATION_CHANNEL_NAME";

        // In this sample, we'll use the same text for the ticker and the expanded notification
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            int importance = NotificationManager.IMPORTANCE_LOW;
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,
                    NOTIFICATION_CHANNEL_NAME, importance);
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.enableVibration(true);
            notificationChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
            notificationManager.createNotificationChannel(notificationChannel);
        }

        final Intent notificationIntent = new Intent(context, SplashActivity.class);
        notificationIntent.setAction(Intent.ACTION_MAIN);
        notificationIntent.addCategory(Intent.CATEGORY_LAUNCHER);
        notificationIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        // The PendingIntent to launch our activity if the user selects this notification
        PendingIntent contentIntent = PendingIntent.getActivity(context, 0,
                notificationIntent, 0);

        // Set the info for the views that show in the notification panel.
        Notification notification = new NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID)
                .setSmallIcon(android.R.drawable.ic_dialog_alert)
                .setWhen(System.currentTimeMillis())
                .setContentTitle("Method Called")
                    .setContentText(key) 
                    .setContentIntent(contentIntent)  
                    .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
                    .build();

            // Send the notification.
            notificationManager.cancel(NOTIFICATION);
            notificationManager.notify(NOTIFICATION, notification);
        }
    }

在清单文件中

        <service
            android:name=".ReminderService"
            android:enabled="true"
            android:exported="false" />

        <receiver android:name=".ReminderReceiver" />

运行固定时间后每天一个方法

Run a method daily after a fixed time

android

simpledateformat