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.
Kullanıcı tarafından başlatılan veri aktarımı işlerini planlama
Kullanıcı tarafından başlatılan bir veri aktarımı işini çalıştırmak için aşağıdakileri yapın:
Uygulamanızın manifest dosyasında
JobServiceve ilişkili izinlerin beyan edildiğinden emin olun:<service android:name="com.example.app.CustomTransferService" android:permission="android.permission.BIND_JOB_SERVICE" android:exported="false"> ... </service>Ayrıca, veri aktarımınız için
JobServiceöğesinin somut bir alt sınıfını tanımlayın:Kotlin
class CustomTransferService : JobService() { ... }
Java
class CustomTransferService extends JobService() { .... }
Manifest dosyasında
RUN_USER_INITIATED_JOBSiznini beyan edin:<manifest ...> <uses-permission android:name="android.permission.RUN_USER_INITIATED_JOBS" /> <application ...> ... </application> </manifest>setUserInitiated()yöntemini birJobInfonesnesi oluştururken çağırın. (Bu yöntem, Android 14'ten itibaren kullanılabilir.) Ayrıca, işinizi oluştururkensetEstimatedNetworkBytes()işlevini çağırarak bir yük boyutu tahmini sunmanızı öneririz.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, 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, 1024 * 1024 * 1024) // ... .build();
İş yürütülürken
JobServicenesnesindesetNotification()işlevini çağırın. CallingsetNotification(), hem Görev Yöneticisi'nde hem de durum çubuğu bildirim alanında kullanıcının işin çalıştığından haberdar olmasını sağlar.Yürütme tamamlandığında, işin tamamlandığını veya yeniden planlanması gerektiğini sisteme bildirmek için
jobFinished()işlevini çağırın.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 } }
Kullanıcıyı işin durumu ve ilerleme durumu hakkında bilgilendirmek için bildirimi düzenli olarak güncelleyin. İşi planlamadan önce aktarım boyutunu belirleyemiyorsanız veya tahmini aktarım boyutunu güncellemeniz gerekiyorsa aktarım boyutu bilindikten sonra güncellemek için yeni API'yi (
updateEstimatedNetworkBytes()) kullanın.
Öneriler
UIDT işlerini etkili bir şekilde çalıştırmak için aşağıdakileri yapın:
İşin ne zaman yürütülmesi gerektiğini belirtmek için ağ kısıtlamalarını ve iş yürütme kısıtlamalarını net bir şekilde tanımlayın.
Görevi
onStartJob()içinde eşzamansız olarak yürütün. Örneğin, bunu eş yordam kullanarak yapabilirsiniz. Görevi eşzamanlı olarak çalıştırmazsanız çalışma ana iş parçacığında çalışır ve onu engelleyebilir. Bu durum ANR'ye neden olabilir.İşin gereğinden uzun süre çalışmasını önlemek için aktarım başarılı olsa da olmasa da tamamlandığında
jobFinished()işlevini çağırın. Böylece iş, gerekenden daha uzun sürmez. Bir işin neden durdurulduğunu öğrenmek içinonStopJob()geri çağırma yöntemini uygulayın veJobParameters.getStopReason()yöntemini çağırın.
Geriye dönük uyumluluk
目前还没有支持 UIDT 作业的 Jetpack 库。因此,我们建议您使用代码来限制变更,以验证您是否在 Android 14 或更高版本上运行。在较低的 Android 版本中,您可以将 WorkManager 的前台服务实现用作回退方法。
以下是检查相应系统版本的代码示例:
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) }
UIDT işlerini durdurma
Both the user and the system can stop user-initiated transfer jobs.
Kullanıcı tarafından, görev yöneticisinden
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.
Sistem tarafından
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.
Kullanıcı tarafından başlatılan veri aktarımı işlerinin planlanmasına izin verilen koşullar
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.
Kullanıcı tarafından başlatılan veri aktarımı işlerine izin verilen kısıtlamalar
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()
Test
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
Ayrıca bkz.
Ek kaynaklar
Kullanıcı tarafından başlatılan veri aktarımları hakkında daha fazla bilgi için aşağıdaki ek kaynaklara bakın:
- UIDT entegrasyonuyla ilgili örnek olay: Google Haritalar, kullanıcı tarafından başlatılan veri aktarımı API'sini kullanarak indirme güvenilirliğini% 10 artırdı