androidx.work

Kotlin |Java

WorkManager is a library used to enqueue deferrable work that is guaranteed to execute sometime after its Constraints are met. WorkManager allows observation of work status and the ability to create complex chains of work.

WorkManager uses an underlying job dispatching service when available based on the following criteria:

Uses JobScheduler for API 23+
Uses a custom AlarmManager + BroadcastReceiver implementation for API 14-22

All work must be done in a ListenableWorker class. A simple implementation, Worker, is recommended as the starting point for most developers. With the optional dependencies, you can also use CoroutineWorker or RxWorker. All background work is given a maximum of ten minutes to finish its execution. After this time has expired, the worker will be signalled to stop.

There are two types of work supported by WorkManager: OneTimeWorkRequest and PeriodicWorkRequest. OneTimeWorkRequests can be chained together into acyclic graphs. Work is eligible for execution when all of its prerequisites are complete. If any of its prerequisites fail or are cancelled, the work will never run.

WorkRequests can accept Constraints, inputs (see Data), and backoff criteria. WorkRequests can be tagged with human-readable Strings (see addTag(String)), and chains of work can be given a uniquely-identifiable name with conflict policies. *

Initializing WorkManager

By default, WorkManager is initialized using a ContentProvider with a default Configuration. ContentProviders are created and run before the Application object, so this allows the WorkManager singleton to be setup before your code can run in most cases. This is suitable for most developers. However, you can provide a custom Configuration by using Configuration.Provider or initialize(android.content.Context, androidx.work.Configuration).

WorkManager and its Interactions with the OS

WorkManager BroadcastReceivers to monitor Constraints on devices before API 23. The BroadcastReceivers are disabled on API 23 and up. In particular, WorkManager listens to the following Intents:

android.intent.action.ACTION_POWER_CONNECTED
android.intent.action.ACTION_POWER_DISCONNECTED
android.intent.action.BATTERY_OKAY
android.intent.action.BATTERY_LOW
android.intent.action.DEVICE_STORAGE_LOW
android.intent.action.DEVICE_STORAGE_OK
android.net.conn.CONNECTIVITY_CHANGE

In addition, WorkManager listens to system time changes and reboots to properly reschedule work in certain situations. For this, it listens to the following Intents:

android.intent.action.BOOT_COMPLETED
android.intent.action.TIME_SET
android.intent.action.TIMEZONE_CHANGED

WorkManager uses the following permissions:

android.permission.WAKE_LOCK to make it can keep the device awake to complete work before API 23
android.permission.ACCESS_NETWORK_STATE to listen to network changes before API 23 and monitor network Constraints
android.permission.RECEIVE_BOOT_COMPLETED to listen to reboots and reschedule work properly.

Note that WorkManager may enable or disable some of its BroadcastReceivers at runtime as needed. This has the side-effect of the system sending ACTION_PACKAGE_CHANGED broadcasts to your app. Please be aware of this use case and architect your app appropriately (especially if you are using widgets - see https://issuetracker.google.com/115575872).

Annotations

ExperimentalExpeditedWork An API surface for expedited WorkRequests.

Interfaces

Configuration.Provider	A class that can provide the `Configuration` for WorkManager and allow for on-demand initialization of WorkManager.
ForegroundUpdater	Manages updating `Notification`s when a `ListenableWorker` transitions to running in the context of a foreground `Service`.
Operation	An object that provides information about the execution of an asynchronous command being performed by `WorkManager`.
ProgressUpdater	Updates progress for a `ListenableWorker`.
RunnableScheduler	Can be used to schedule `Runnable`s after a delay in milliseconds.

Classes

ArrayCreatingInputMerger	An `InputMerger` that attempts to merge the inputs, creating arrays when necessary.
Configuration	The Configuration object used to customize `WorkManager` upon initialization.
Configuration.Builder	A Builder for `Configuration`s.
Constraints	A specification of the requirements that need to be met before a `WorkRequest` can run.
Constraints.Builder	A Builder for a `Constraints` object.
Data	A persistable set of key/value pairs which are used as inputs and outputs for `ListenableWorker`s.
Data.Builder	A builder for `Data` objects.
DelegatingWorkerFactory	A `WorkerFactory` which delegates to other factories.
ForegroundInfo	The information required when a `ListenableWorker` runs in the context of a foreground service.
InputMerger	An abstract class that allows the user to define how to merge a list of inputs to a `ListenableWorker`.
InputMergerFactory	A factory object that creates `InputMerger` instances.
ListenableWorker	A class that can perform work asynchronously in `WorkManager`.
ListenableWorker.Result	The result of a `ListenableWorker`'s computation.
OneTimeWorkRequest	A `WorkRequest` for non-repeating work.
OneTimeWorkRequest.Builder	Builder for `OneTimeWorkRequest`s.
Operation.State	The lifecycle state of an `Operation`.
Operation.State.FAILURE	This represents an `Operation` which has failed.
Operation.State.IN_PROGRESS	This represents an `Operation` which is in progress.
Operation.State.SUCCESS	This represents an `Operation` which is successful.
OverwritingInputMerger	An `InputMerger` that attempts to add all keys from all inputs to the output.
PeriodicWorkRequest	A `WorkRequest` for repeating work.
PeriodicWorkRequest.Builder	Builder for `PeriodicWorkRequest`s.
RxWorker	RxJava2 interoperability Worker implementation.
WorkContinuation	A class that allows you to chain together `OneTimeWorkRequest`s.
Worker	A class that performs work synchronously on a background thread provided by `WorkManager`.
WorkerFactory	A factory object that creates `ListenableWorker` instances.
WorkerParameters	Setup parameters for a `ListenableWorker`.
WorkInfo	Information about a particular `WorkRequest` containing the id of the WorkRequest, its current `WorkInfo.State`, output, tags, and run attempt count.
WorkManager	WorkManager is a library used to enqueue deferrable work that is guaranteed to execute sometime after its `Constraints` are met.
WorkManagerInitializer	Initializes `WorkManager` using `androidx.startup`.
WorkQuery	A specification for querying `WorkRequest`s.
WorkQuery.Builder	A builder for `WorkQuery`.
WorkRequest	The base class for specifying parameters for work that should be enqueued in `WorkManager`.
WorkRequest.Builder<B extends Builder<?, ?>, W extends WorkRequest>	A builder for `WorkRequest`s.

Enums

BackoffPolicy	An enumeration of backoff policies when retrying work.
ExistingPeriodicWorkPolicy	An enumeration of the conflict resolution policies available to unique `PeriodicWorkRequest`s in case of a collision.
ExistingWorkPolicy	An enumeration of the conflict resolution policies available to unique `OneTimeWorkRequest`s in case of a collision.
NetworkType	An enumeration of various network types that can be used as `Constraints` for work.
OutOfQuotaPolicy	An enumeration of policies that help determine out of quota behavior for expedited jobs.
WorkInfo.State	The current lifecycle state of a `WorkRequest`.