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.
Cómo programar tareas de transferencia de datos que inicia el usuario
Para ejecutar una tarea de transferencia de datos que inicia el usuario, haz lo siguiente:
Asegúrate de que tu app haya declarado los permisos
JobServicey los permisos asociados en su manifiesto:<service android:name="com.example.app.CustomTransferService" android:permission="android.permission.BIND_JOB_SERVICE" android:exported="false"> ... </service>Además, define una subclase concreta de
JobServicepara tu transferencia de datos:Kotlin
class CustomTransferService : JobService() { ... }
Java
class CustomTransferService extends JobService() { .... }
Declara el permiso
RUN_USER_INITIATED_JOBSen el manifiesto:<manifest ...> <uses-permission android:name="android.permission.RUN_USER_INITIATED_JOBS" /> <application ...> ... </application> </manifest>Llama al método
setUserInitiated()cuando compiles un objetoJobInfo. (Este método está disponible a partir de Android 14). También te recomendamos que ofrezcas una estimación del tamaño de la carga útil llamando asetEstimatedNetworkBytes()durante la creación de la tarea.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();
Mientras se ejecuta el trabajo, llama a
setNotification()en el objetoJobService. La llamada asetNotification()le informa al usuario que el trabajo está en ejecución, tanto en el Administrador de tareas como en el área de notificaciones de la barra de estado.Cuando finalice la ejecución, llama a
jobFinished()para indicarle al sistema que se completó la tarea o que se debe reprogramar.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 } }
Actualiza la notificación de forma periódica para mantener informado al usuario sobre el estado y el progreso de la tarea. Si no puedes determinar el tamaño de transferencia antes de programar la tarea o necesitas actualizar el tamaño de transferencia estimado, usa la nueva API,
updateEstimatedNetworkBytes(), para actualizar el tamaño de transferencia después de que se haga conocido.
Recomendaciones
Para ejecutar trabajos de UIDT de manera eficaz, haz lo siguiente:
Define claramente las restricciones de red y las restricciones de ejecución del trabajo para especificar cuándo se debe ejecutar el trabajo.
Ejecuta la tarea de forma asíncrona en
onStartJob(); por ejemplo, puedes hacerlo con una corrutina. Si no ejecutas la tarea de forma asíncrona, el trabajo se ejecutará en el subproceso principal y podría bloquearlo, lo que puede provocar un error de ANR.Para evitar que el trabajo se ejecute más tiempo del necesario, llama a
jobFinished()cuando finalice la transferencia, ya sea que se realice correctamente o no. De esta manera, el trabajo no se ejecutará más tiempo del necesario. Para descubrir por qué se detuvo un trabajo, implementa el método de devolución de llamadaonStopJob()y llama aJobParameters.getStopReason().
Retrocompatibilidad
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) }
Detén los trabajos de UIDT
El usuario y el sistema pueden detener tareas de transferencia que inicia el usuario.
Por el usuario, desde el Administrador de tareas
El usuario puede detener una tarea de transferencia de datos que inicia él mismo y que aparece en el Administrador de tareas.
En el momento en que el usuario presiona Detener, el sistema hace lo siguiente:
- Finaliza el proceso de tu app de inmediato, incluidos todas las demás tareas o servicios en primer plano que se ejecutan.
- No llama a
onStopJob()para ninguna tarea en ejecución. - Evita la reprogramación de las tareas visibles para el usuario.
Por estos motivos, te recomendamos que proporciones controles en la notificación publicada para la tarea para permitir que se detenga y se reprograme la tarea con facilidad.
Ten en cuenta que, en circunstancias especiales, el botón Detener no aparece junto a la tarea en el Administrador de tareas, o la tarea no se muestra en el Administrador en absoluto.
Por el sistema
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.
Condiciones permitidas para programar tareas de transferencia de datos que inicia el usuario
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.
Restricciones permitidas para las tareas de transferencia de datos que inicia el usuario
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()
Prueba
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
Consulta también
- Descripción general de las tareas en segundo plano
- Opciones de tareas en segundo plano de transferencia de datos
Recursos adicionales
Para obtener más información sobre las transferencias de datos iniciadas por el usuario, consulta los siguientes recursos adicionales:
- Caso de éxito sobre la integración de la UIDT: Google Maps mejoró la confiabilidad de las descargas en un 10% con la API de transferencia de datos iniciada por el usuario