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
如需运行用户发起的数据传输作业,请执行以下操作:
确保您的应用已在其清单中声明
JobService
和关联的权限:<service android:name="com.example.app.CustomTransferService" android:permission="android.permission.BIND_JOB_SERVICE" android:exported="false"> ... </service>
此外,还要为数据转移定义
JobService
的具体子类:Kotlin
class CustomTransferService : JobService() { ... }
Java
class CustomTransferService extends JobService() { .... }
在清单中声明
RUN_USER_INITIATED_JOBS
权限:<manifest ...> <uses-permission android:name="android.permission.RUN_USER_INITIATED_JOBS" /> <application ...> ... </application> </manifest>
构建
JobInfo
对象时,调用setUserInitiated()
方法。(此方法从 Android 14 开始提供。)我们还建议您在创建作业时通过调用setEstimatedNetworkBytes()
提供载荷大小估算值。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();
在作业执行期间,对
JobService
对象调用setNotification()
。调用setNotification()
会在任务管理器和状态栏通知区域中告知用户作业正在运行。执行完成后,调用
jobFinished()
以向系统表明作业已完成,或者应重新调度作业。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 } }
定期更新通知,让用户了解作业的状态和进度。如果在安排作业之前无法确定传输大小,或者需要更新估计的传输大小,请在知道传输大小之后使用新的 API
updateEstimatedNetworkBytes()
更新传输大小。
建议
如需有效运行 UIDT 作业,请执行以下操作:
明确定义网络限制和作业执行限制,以指定作业的执行时间。
在
onStartJob()
中异步执行任务;例如,您可以使用协程来执行此操作。如果您不异步运行任务,工作将在主线程上运行,可能会阻塞主线程,从而导致 ANR。为避免作业运行时间过长,请在转移完成后(无论成功还是失败)调用
jobFinished()
。这样,作业就不会运行过长时间。如需了解作业停止的原因,请实现onStopJob()
回调方法并调用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
用户可以停止显示在任务管理器中的用户发起的传输作业。
在用户按 Stop 时,系统会执行以下操作:
- 立即终止应用的进程,包括正在运行的所有其他作业或前台服务。
- 不针对任何正在运行的作业调用
onStopJob()
。 - 阻止重新调度用户可见的作业。
因此,建议在发布的作业通知中提供控件,以便顺利停止和重新调度作业。
请注意,在特殊情况下,Stop 按钮不会显示在任务管理器中的作业旁边,或者该作业根本不会显示在任务管理器中。
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
只有当应用处于可见窗口中或满足特定条件时,应用才能启动用户发起的数据传输作业:
- 如果应用可以从后台启动 activity,则也可以从后台启动用户发起的数据传输作业。
- 如果应用在最近用过屏幕上现有任务的返回堆栈中有 activity,单靠这一点并不允许运行用户发起的数据传输作业。
如果作业安排在未满足必要条件的时间运行,则作业将失败并返回 RESULT_FAILURE
错误代码。
Ograniczenia dozwolone w przypadku zadań przesyłania danych inicjowanych przez użytkownika
Aby obsługiwać zadania działające w optymalnych momentach, Android umożliwia przypisywanie ograniczeń do każdego typu zadania. Te ograniczenia są dostępne od Androida 13.
Uwaga: w tej tabeli porównano tylko ograniczenia, które różnią się w zależności od typu zadania. Wszystkie ograniczenia znajdziesz na stronie dla deweloperów JobScheduler lub w sekcji ograniczenia dotyczące zadań.
W tabeli poniżej znajdziesz różne typy zadań, które obsługują dane ograniczenie zadania, a także zestaw ograniczeń zadań obsługiwanych przez WorkManager. Użyj paska wyszukiwania przed tabelą, aby filtrować tabelę według nazwy metody ograniczenia zadania.
Oto ograniczenia dozwolone w przypadku zadań przesyłania danych inicjowanych przez użytkownika:
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:
- Studium przypadku dotyczące integracji UIDT: dzięki interfejsowi User Initiated Data Transfer API Mapy Google zwiększyły niezawodność pobierania o 10%