Przenoszenie danych inicjowane przez użytkownika

If you need to perform a data transfer that may take a long time, you can create a JobScheduler job and identify it as a user-initiated data transfer (UIDT) job. UIDT jobs are intended for longer-duration data transfers that are initiated by the device user, such as downloading a file from a remote server. UIDT jobs were introduced with Android 14 (API level 34).

User-initiated data transfer jobs are started by the user. These jobs require a notification, start immediately, and may be able to run for an extended period of time as system conditions allow. You can run several user-initiated data transfer jobs concurrently.

User initiated jobs must be scheduled while the application is visible to the user (or in one of the allowed conditions). After all constraints are met, user initiated jobs can be executed by the OS, subject to system health restrictions. The system may also use the provided estimated payload size to determine how long the job executes.

Planowanie zadań przenoszenia danych inicjowanych przez użytkownika

Aby uruchomić zadanie przesyłania danych inicjowane przez użytkownika:

  1. Upewnij się, że w pliku manifestu aplikacji zadeklarowano JobService i powiązane uprawnienia:

    <service android:name="com.example.app.CustomTransferService"
        android:permission="android.permission.BIND_JOB_SERVICE"
        android:exported="false">
        ...
</service>

    Zdefiniuj też konkretną podklasę JobService dla transferu danych:

    Kotlin

    class CustomTransferService : JobService() {
  ...
}

    Java

    class CustomTransferService extends JobService() {

    ....

}

  2. Zadeklaruj uprawnienie RUN_USER_INITIATED_JOBS w pliku manifestu:

    <manifest ...>
    <uses-permission android:name="android.permission.RUN_USER_INITIATED_JOBS" />
    <application ...>
        ...
    </application>
</manifest>

  3. Podczas tworzenia obiektu JobInfo wywołaj metodę setUserInitiated(). (Ta metoda jest dostępna od Androida 14). Zalecamy też podanie szacunkowego rozmiaru ładunku, wywołując funkcję setEstimatedNetworkBytes() podczas tworzenia zadania.

    Kotlin

    val networkRequestBuilder = NetworkRequest.Builder()
        // Add or remove capabilities based on your requirements.
        // For example, this code specifies that the job won't run
        // unless there's a connection to the internet (not just a local
        // network), and the connection doesn't charge per-byte.
        .addCapability(NET_CAPABILITY_INTERNET)
        .addCapability(NET_CAPABILITY_NOT_METERED)
        .build()

val jobInfo = JobInfo.Builder(jobId,
              ComponentName(mContext, CustomTransferService::class.java))
        // ...
        .setUserInitiated(true)
        .setRequiredNetwork(networkRequestBuilder)
        // Provide your estimate of the network traffic here
        .setEstimatedNetworkBytes(1024 * 1024 * 1024)
        // ...
        .build()

    Java

    NetworkRequest networkRequest = new NetworkRequest.Builder()
    // Add or remove capabilities based on your requirements.
    // For example, this code specifies that the job won't run
    // unless there's a connection to the internet (not just a local
    // network), and the connection doesn't charge per-byte.
    .addCapability(NET_CAPABILITY_INTERNET)
    .addCapability(NET_CAPABILITY_NOT_METERED)
    .build();

JobInfo jobInfo = JobInfo.Builder(jobId,
        new ComponentName(mContext, CustomTransferService.class))
    // ...
    .setUserInitiated(true)
    .setRequiredNetwork(networkRequest)
    // Provide your estimate of the network traffic here
    .setEstimatedNetworkBytes(1024 * 1024 * 1024)
    // ...
    .build();

  4. Podczas wykonywania zadania wywołaj funkcję setNotification() w obiekcie JobService. Wywołanie funkcji setNotification() informuje użytkownika o tym, że zadanie jest wykonywane, zarówno w Menedżerze zadań, jak i w obszarze powiadomień na pasku stanu.

    Po zakończeniu wykonania wywołaj funkcję jobFinished(), aby poinformować system, że zadanie zostało wykonane lub należy je ponownie zaplanować.

    Kotlin

    class CustomTransferService: JobService() {
    private val scope = CoroutineScope(Dispatchers.IO)

    @RequiresApi(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
    override fun onStartJob(params: JobParameters): Boolean {
        val notification = Notification.Builder(applicationContext,
                              NOTIFICATION_CHANNEL_ID)
            .setContentTitle("My user-initiated data transfer job")
            .setSmallIcon(android.R.mipmap.myicon)
            .setContentText("Job is running")
            .build()

        setNotification(params, notification.id, notification,
                JobService.JOB_END_NOTIFICATION_POLICY_DETACH)
        // Execute the work associated with this job asynchronously.
        scope.launch {
            doDownload(params)
        }
        return true
    }

    private suspend fun doDownload(params: JobParameters) {
        // Run the relevant async download task, then call
        // jobFinished once the task is completed.
        jobFinished(params, false)
    }

    // Called when the system stops the job.
    override fun onStopJob(params: JobParameters?): Boolean {
        // Asynchronously record job-related data, such as the
        // stop reason.
        return true // or return false if job should end entirely
    }
}

    Java

    class CustomTransferService extends JobService{
    @RequiresApi(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
    @Override
    public boolean onStartJob(JobParameters params) {
        Notification notification = Notification.Builder(getBaseContext(),
                                        NOTIFICATION_CHANNEL_ID)
                .setContentTitle("My user-initiated data transfer job")
                .setSmallIcon(android.R.mipmap.myicon)
                .setContentText("Job is running")
                .build();

        setNotification(params, notification.id, notification,
                          JobService.JOB_END_NOTIFICATION_POLICY_DETACH)
        // Execute the work associated with this job asynchronously.
        new Thread(() -> doDownload(params)).start();
        return true;
    }

    private void doDownload(JobParameters params) {
        // Run the relevant async download task, then call
        // jobFinished once the task is completed.
        jobFinished(params, false);
    }

    // Called when the system stops the job.
    @Override
    public boolean onStopJob(JobParameters params) {
        // Asynchronously record job-related data, such as the
        // stop reason.
        return true; // or return false if job should end entirely
    }
}

  5. Okresowo aktualizuj powiadomienie, aby informować użytkownika o stanie i postępach zadania. Jeśli nie możesz określić rozmiaru transferu przed zaplanowaniem zadania lub musisz zaktualizować szacowany rozmiar transferu, użyj nowego interfejsu API updateEstimatedNetworkBytes(), aby zaktualizować rozmiar transferu po jego ustaleniu.

Rekomendacje

Aby skutecznie uruchamiać zadania UIDT:

  1. Jasno określ wymogi związane z siecią i ograniczenia wykonywania zadań, aby określić, kiedy zadanie powinno zostać wykonane.

  2. Wykonaj zadanie asynchronicznie w onStartJob(). Możesz to zrobić na przykład za pomocą współprogramu. Jeśli nie wykonasz zadania asynchronicznie, będzie ono działać w wątku głównym i może go zablokować, co może spowodować błąd ANR.

  3. Aby uniknąć niepotrzebnego przedłużania działania zadania, po zakończeniu transferu wywołaj funkcję jobFinished(), niezależnie od tego, czy transfer się powiódł, czy nie. Dzięki temu zadanie nie będzie uruchomione dłużej niż to konieczne. Aby dowiedzieć się, dlaczego zadanie zostało zatrzymane, zaimplementuj metodę wywołania zwrotnego onStopJob() i wywołaj JobParameters.getStopReason().

Zgodność wsteczna

There is currently no Jetpack library that supports UIDT jobs. For this reason, we recommend that you gate your change with code that verifies that you're running on Android 14 or higher. On lower Android versions, you can use WorkManager's foreground service implementation as a fallback approach.

Here's an example of code that checks for the appropriate system version:

Kotlin

fun beginTask() {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
        scheduleDownloadFGSWorker(context)
    } else {
        scheduleDownloadUIDTJob(context)
    }
}

private fun scheduleDownloadUIDTJob(context: Context) {
    // build jobInfo
    val jobScheduler: JobScheduler =
        context.getSystemService(Context.JOB_SCHEDULER_SERVICE) as JobScheduler
    jobScheduler.schedule(jobInfo)
}

private fun scheduleDownloadFGSWorker(context: Context) {
    val myWorkRequest = OneTimeWorkRequest.from(DownloadWorker::class.java)
    WorkManager.getInstance(context).enqueue(myWorkRequest)
}

Java

public void beginTask() {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
        scheduleDownloadFGSWorker(context);
    } else {
        scheduleDownloadUIDTJob(context);
    }
}

private void scheduleDownloadUIDTJob(Context context) {
    // build jobInfo
    JobScheduler jobScheduler =
            (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
    jobScheduler.schedule(jobInfo);
}

private void scheduleDownloadFGSWorker(Context context) {
    OneTimeWorkRequest myWorkRequest = OneTimeWorkRequest.from(DownloadWorker.class);
    WorkManager.getInstance(context).enqueue(myWorkRequest)
}

Zatrzymywanie zadań UIDT

Both the user and the system can stop user-initiated transfer jobs.

Przez użytkownika w Menedżerze zadań

The user can stop a user-initiated data transfer job that appears in the Task Manager.

At the moment that the user presses Stop, the system does the following:

  • Terminates your app's process immediately, including all other jobs or foreground services running.
  • Doesn't call onStopJob() for any running jobs.
  • Prevents user-visible jobs from being rescheduled.

For these reasons, it's recommended to provide controls in the notification posted for the job to allow gracefully stopping and rescheduling the job.

Note that, under special circumstances, the Stop button doesn't appear next to the job in the Task Manager, or the job isn't shown in the Task Manager at all.

przez system,

Unlike regular jobs, user-initiated data transfer jobs are unaffected by App Standby Buckets quotas. However, the system still stops the job if any of the following conditions occur:

  • A developer-defined constraint is no longer met.
  • The system determines that the job has run for longer than necessary to complete the data transfer task.
  • The system needs to prioritize system health and stop jobs due to increased thermal state.
  • The app process is killed due to low device memory.

When the job is stopped by the system for reasons other than low device memory, the system calls onStopJob(), and the system retries the job at a time that the system deems to be optimal. Make sure that your app can persist the data transfer state even if onStopJob() isn't called, and that your app can restore this state when onStartJob() is called again.

Warunki, które muszą być spełnione, aby można było zaplanować zadania przesyłania danych inicjowane przez użytkownika

Apps can only start a user-initiated data transfer job if the app is in the visible window, or if certain conditions are met:

  • If an app can launch activities from the background, it can also launch user-initiated data transfer jobs from the background.
  • If an app has an activity in the back stack of an existing task on the Recents screen, that alone doesn't allow a user-initiated data transfer job to run.

If the job is scheduled to run at a time when the necessary conditions are not met, the job fails and returns a RESULT_FAILURE error code.

Ograniczenia dozwolone w przypadku zadań przesyłania danych inicjowanych przez użytkownika

To support jobs running at optimal points, Android offers the ability to assign constraints to each job type. These constraints are available as of Android 13.

Note: The following table only compares the constraints that vary between each job type. See JobScheduler developer page or work constraints for all constraints.

The following table shows the different job types that support a given job constraint, as well as the set of job constraints that WorkManager supports. Use the search bar before the table to filter the table by the name of a job constraint method.

These are the constraints allowed with user-initiated data transfer jobs:

  • setBackoffCriteria(JobInfo.BACKOFF_POLICY_EXPONENTIAL)
  • setClipData()
  • setEstimatedNetworkBytes()
  • setMinimumNetworkChunkBytes()
  • setPersisted()
  • setNamespace()
  • setRequiredNetwork()
  • setRequiredNetworkType()
  • setRequiresBatteryNotLow()
  • setRequiresCharging()
  • setRequiresStorageNotLow()

Testowanie

The following list shows some steps on how to test your app's jobs manually:

  • To get the job ID, get the value that is defined upon the job being built.

  • To run a job immediately, or to retry a stopped job, run the following command in a terminal window:

    adb shell cmd jobscheduler run -f APP_PACKAGE_NAME JOB_ID

  • To simulate the system force-stopping a job (due to system health or out-of-quota conditions), run the following command in a terminal window:

    adb shell cmd jobscheduler timeout TEST_APP_PACKAGE TEST_JOB_ID

Zobacz również

Dodatkowe materiały

Więcej informacji o zainicjowanych przez użytkownika transferach danych znajdziesz w tych dodatkowych materiałach: