ユーザーが開始するデータ転送

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.

ユーザーが開始するデータ転送ジョブのスケジュールを設定する

ユーザーが開始するデータ転送ジョブを実行するには、次の手順を行います。

1. アプリのマニフェストで JobService と関連する 権限が宣言されていることを確認します。

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

   また、データ転送用に JobService の具体的なサブクラスを定義します。

   Kotlin

   class CustomTransferService : JobService() {
     ...
   }

   Java

   class CustomTransferService extends JobService() {
   
       ....
   
   }

2. マニフェストで RUN_USER_INITIATED_JOBS 権限を宣言します。

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

3. setUserInitiated() メソッドを JobInfo オブジェクトを作成するときに呼び出します（このメソッドは Android 14 以降で使用できます）。 また、ジョブの作成時に setEstimatedNetworkBytes()を呼び出して、ペイロード サイズ を見積もることもおすすめします 。

   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();

4. ジョブの実行中に、 setNotification() を JobService オブジェクトで呼び出します。setNotification() を呼び出すと、タスク マネージャーとステータスバーの通知領域の両方で、ジョブが実行されていることをユーザーに知らせることができます。

   実行が完了したら、jobFinished() を呼び出して、ジョブが完了したこと、またはジョブのスケジュールを再設定する必要があることをシステムに通知します。

   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. 通知を定期的に更新して、ジョブのステータスと進行状況をユーザーに知らせます。ジョブのスケジュールを設定する前に転送サイズを特定できない場合や、推定転送サイズを更新する必要がある場合は、新しい API である updateEstimatedNetworkBytes() を使用して、判明した転送サイズを更新します。

推奨事項

UIDT ジョブを効果的に実行するには、次の操作を行います。

1. ネットワークの制約とジョブの実行の制約を明確に定義して、ジョブを実行するタイミングを指定します。

2. onStartJob() でタスクを非同期で実行します。たとえば、 コルーチンを使用すると、これを行うことができます。タスクを非同期で実行しない場合、作業はメインスレッドで実行され、メインスレッドがブロックされる可能性があります。これにより、ANR が発生する可能性があります。

3. ジョブが不要に長く実行されないように、転送が成功したか失敗したかにかかわらず、転送が完了したら jobFinished()を呼び出します。これにより、ジョブが不要に長く実行されることはありません。ジョブが停止した理由を調べるには、 onStopJob() コールバック メソッドを実装し、 JobParameters.getStopReason() を呼び出します。

下位互換性

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:

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)
}

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 ジョブを停止する

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

ユーザーがタスク マネージャーから停止

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.

システムによる停止

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.

ユーザーが開始するデータ転送ジョブのスケジュールを設定できる条件

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.

ユーザーが開始するデータ転送ジョブで許可される制約

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()

テスト

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

関連ドキュメント

• バックグラウンド タスクの概要
• データ転送のバックグラウンド タスク オプション

参考情報

ユーザーが開始したデータ転送の詳細については、次のリソースをご覧ください。

• UIDT 統合に関する事例紹介: Google マップはユーザーが開始したデータ転送 API を使用してダウンロードの信頼性を 10% 向上させました