Summary: Methods | Inherited Methods

WorkManager

public abstract class WorkManager
extends Object

java.lang.Object
↳	androidx.work.WorkManager

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. You can enqueue requests using WorkManager as follows:

 WorkManager workManager = WorkManager.getInstance();
 workManager.enqueue(new OneTimeWorkRequest.Builder(FooWorker.class).build());

A WorkRequest has an associated id that can be used for lookups and observation as follows:

 WorkRequest request = new OneTimeWorkRequest.Builder(FooWorker.class).build();
 workManager.enqueue(request);
 LiveData<WorkInfo> status = workManager.getWorkInfoByIdLiveData(request.getId());
 status.observe(...);

You can also use the id for cancellation:

 WorkRequest request = new OneTimeWorkRequest.Builder(FooWorker.class).build();
 workManager.enqueue(request);
 workManager.cancelWorkById(request.getId());

You can chain work as follows:

 WorkRequest request1 = new OneTimeWorkRequest.Builder(FooWorker.class).build();
 WorkRequest request2 = new OneTimeWorkRequest.Builder(BarWorker.class).build();
 WorkRequest request3 = new OneTimeWorkRequest.Builder(BazWorker.class).build();
 workManager.beginWith(request1, request2).then(request3).enqueue();

Each call to beginWith(OneTimeWorkRequest) or beginWith(List) returns a WorkContinuation upon which you can call WorkContinuation.then(OneTimeWorkRequest) or WorkContinuation.then(List) to chain further work. This allows for creation of complex chains of work. For example, to create a chain like this:

            A
            |
      +----------+
      |          |
      B          C
      |
   +----+
   |    |
   D    E

you would enqueue them as follows:

 WorkContinuation continuation = workManager.beginWith(A);
 continuation.then(B).then(D, E).enqueue();  // A is implicitly enqueued here
 continuation.then(C).enqueue();

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 WorkRequest.Builder.addTag(String)), and chains of work can be given a uniquely-identifiable name (see beginUniqueWork(String, ExistingWorkPolicy, OneTimeWorkRequest)).

Manually initializing WorkManager

You can manually initialize WorkManager and provide a custom Configuration for it. Please see initialize(Context, Configuration).

Summary

Public methods
`abstract WorkContinuation`	`beginUniqueWork(String uniqueWorkName, ExistingWorkPolicy existingWorkPolicy, List<OneTimeWorkRequest> work)` This method allows you to begin unique chains of work for situations where you only want one chain with a given name to be active at a time.
`final WorkContinuation`	`beginUniqueWork(String uniqueWorkName, ExistingWorkPolicy existingWorkPolicy, OneTimeWorkRequest work)` This method allows you to begin unique chains of work for situations where you only want one chain with a given name to be active at a time.
`final WorkContinuation`	`beginWith(OneTimeWorkRequest work)` Begins a chain with one or more `OneTimeWorkRequest`s, which can be enqueued together in the future using `WorkContinuation.enqueue()`.
`abstract WorkContinuation`	`beginWith(List<OneTimeWorkRequest> work)` Begins a chain with one or more `OneTimeWorkRequest`s, which can be enqueued together in the future using `WorkContinuation.enqueue()`.
`abstract Operation`	`cancelAllWork()` Cancels all unfinished work.
`abstract Operation`	`cancelAllWorkByTag(String tag)` Cancels all unfinished work with the given tag.
`abstract Operation`	`cancelUniqueWork(String uniqueWorkName)` Cancels all unfinished work in the work chain with the given name.
`abstract Operation`	`cancelWorkById(UUID id)` Cancels work with the given id if it isn't finished.
`final Operation`	`enqueue(WorkRequest workRequest)` Enqueues one or more items for background processing.
`abstract Operation`	`enqueue(List<? extends WorkRequest> requests)` Enqueues one or more items for background processing.
`abstract Operation`	`enqueueUniquePeriodicWork(String uniqueWorkName, ExistingPeriodicWorkPolicy existingPeriodicWorkPolicy, PeriodicWorkRequest periodicWork)` This method allows you to enqueue a uniquely-named `PeriodicWorkRequest`, where only one PeriodicWorkRequest of a particular name can be active at a time.
`Operation`	`enqueueUniqueWork(String uniqueWorkName, ExistingWorkPolicy existingWorkPolicy, OneTimeWorkRequest work)` This method allows you to enqueue `work` requests to a uniquely-named `WorkContinuation`, where only one continuation of a particular name can be active at a time.
`abstract Operation`	`enqueueUniqueWork(String uniqueWorkName, ExistingWorkPolicy existingWorkPolicy, List<OneTimeWorkRequest> work)` This method allows you to enqueue `work` requests to a uniquely-named `WorkContinuation`, where only one continuation of a particular name can be active at a time.
`static WorkManager`	`getInstance()` Retrieves the `default` singleton instance of `WorkManager`.
`abstract ListenableFuture<Long>`	`getLastCancelAllTimeMillis()` Gets a `ListenableFuture` of the last time all work was cancelled.
`abstract LiveData<Long>`	`getLastCancelAllTimeMillisLiveData()` Gets a `LiveData` of the last time all work was cancelled.
`abstract ListenableFuture<WorkInfo>`	`getWorkInfoById(UUID id)` Gets a `ListenableFuture` of the `WorkInfo` for a given work id.
`abstract LiveData<WorkInfo>`	`getWorkInfoByIdLiveData(UUID id)` Gets a `LiveData` of the `WorkInfo` for a given work id.
`abstract ListenableFuture<List<WorkInfo>>`	`getWorkInfosByTag(String tag)` Gets a `ListenableFuture` of the `WorkInfo` for all work for a given tag.
`abstract LiveData<List<WorkInfo>>`	`getWorkInfosByTagLiveData(String tag)` Gets a `LiveData` of the `WorkInfo` for all work for a given tag.
`abstract ListenableFuture<List<WorkInfo>>`	`getWorkInfosForUniqueWork(String uniqueWorkName)` Gets a `ListenableFuture` of the `WorkInfo` for all work in a work chain with a given unique name.
`abstract LiveData<List<WorkInfo>>`	`getWorkInfosForUniqueWorkLiveData(String uniqueWorkName)` Gets a `LiveData` of the `WorkInfo` for all work in a work chain with a given unique name.
`static void`	`initialize(Context context, Configuration configuration)` Used to do a one-time initialization of the `WorkManager` singleton with a custom `Configuration`.
`abstract Operation`	`pruneWork()` Prunes all eligible finished work from the internal database.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()`
`boolean`	`equals(Object arg0)`
`void`	`finalize()`
`final Class<?>`	`getClass()`
`int`	`hashCode()`
`final void`	`notify()`
`final void`	`notifyAll()`
`String`	`toString()`
`final void`	`wait(long arg0, int arg1)`
`final void`	`wait(long arg0)`
`final void`	`wait()`

Public methods

beginUniqueWork

public abstract WorkContinuation beginUniqueWork (String uniqueWorkName, 
                ExistingWorkPolicy existingWorkPolicy, 
                List<OneTimeWorkRequest> work)

This method allows you to begin unique chains of work for situations where you only want one chain with a given name to be active at a time. For example, you may only want one sync operation to be active. If there is one pending, you can choose to let it run or replace it with your new work.

The uniqueWorkName uniquely identifies this set of work.

If this method determines that new work should be enqueued and run, all records of previous work with uniqueWorkName will be pruned. If this method determines that new work should NOT be run, then the entire chain will be considered a no-op.

If any work in the chain fails or is cancelled, all of its dependent work inherits that state and will never run. This is particularly important if you are using APPEND as your ExistingWorkPolicy.

Parameters
`uniqueWorkName`	`String`: A unique name which for this chain of work
`existingWorkPolicy`	`ExistingWorkPolicy`: An `ExistingWorkPolicy`; see below for more information
`work`	`List`: One or more `OneTimeWorkRequest` to enqueue. `REPLACE` ensures that if there is pending work labelled with `uniqueWorkName`, it will be cancelled and the new work will run. `KEEP` will run the new sequence of work only if there is no pending work labelled with `uniqueWorkName`. `APPEND` will create a new sequence of work if there is no existing work with `uniqueWorkName`; otherwise, `work` will be added as a child of all leaf nodes labelled with `uniqueWorkName`.

Returns
`WorkContinuation`	A `WorkContinuation` that allows further chaining

beginUniqueWork

public final WorkContinuation beginUniqueWork (String uniqueWorkName, 
                ExistingWorkPolicy existingWorkPolicy, 
                OneTimeWorkRequest work)

The uniqueWorkName uniquely identifies this set of work.

Parameters
`uniqueWorkName`	`String`: A unique name which for this chain of work
`existingWorkPolicy`	`ExistingWorkPolicy`: An `ExistingWorkPolicy`
`work`	`OneTimeWorkRequest`: The `OneTimeWorkRequest` to enqueue. `REPLACE` ensures that if there is pending work labelled with `uniqueWorkName`, it will be cancelled and the new work will run. `KEEP` will run the new sequence of work only if there is no pending work labelled with `uniqueWorkName`. `APPEND` will create a new sequence of work if there is no existing work with `uniqueWorkName`; otherwise, `work` will be added as a child of all leaf nodes labelled with `uniqueWorkName`.

Returns
`WorkContinuation`	A `WorkContinuation` that allows further chaining

beginWith

public final WorkContinuation beginWith (OneTimeWorkRequest work)

Begins a chain with one or more OneTimeWorkRequests, which can be enqueued together in the future using WorkContinuation.enqueue().

If any work in the chain fails or is cancelled, all of its dependent work inherits that state and will never run.

Parameters
`work`	`OneTimeWorkRequest`: One or more `OneTimeWorkRequest` to start a chain of work

Returns
`WorkContinuation`	A `WorkContinuation` that allows for further chaining of dependent `OneTimeWorkRequest`

beginWith

public abstract WorkContinuation beginWith (List<OneTimeWorkRequest> work)

Begins a chain with one or more OneTimeWorkRequests, which can be enqueued together in the future using WorkContinuation.enqueue().

If any work in the chain fails or is cancelled, all of its dependent work inherits that state and will never run.

Parameters
`work`	`List`: One or more `OneTimeWorkRequest` to start a chain of work

Returns
`WorkContinuation`	A `WorkContinuation` that allows for further chaining of dependent `OneTimeWorkRequest`

cancelAllWork

public abstract Operation cancelAllWork ()

Cancels all unfinished work. Use this method with extreme caution! By invoking it, you will potentially affect other modules or libraries in your codebase. It is strongly recommended that you use one of the other cancellation methods at your disposal.

Upon cancellation, ListenableWorker.onStopped() will be invoked for any affected workers.

Returns
`Operation`	An `Operation` that can be used to determine when the cancelAllWork has completed

cancelAllWorkByTag

public abstract Operation cancelAllWorkByTag (String tag)

Cancels all unfinished work with the given tag. Note that cancellation is a best-effort policy and work that is already executing may continue to run. Upon cancellation, ListenableWorker.onStopped() will be invoked for any affected workers.

Parameters
`tag`	`String`: The tag used to identify the work

Returns
`Operation`	An `Operation` that can be used to determine when the cancelAllWorkByTag has completed

cancelUniqueWork

public abstract Operation cancelUniqueWork (String uniqueWorkName)

Cancels all unfinished work in the work chain with the given name. Note that cancellation is a best-effort policy and work that is already executing may continue to run. Upon cancellation, ListenableWorker.onStopped() will be invoked for any affected workers.

Parameters
`uniqueWorkName`	`String`: The unique name used to identify the chain of work

Returns
`Operation`	An `Operation` that can be used to determine when the cancelUniqueWork has completed

cancelWorkById

public abstract Operation cancelWorkById (UUID id)

Cancels work with the given id if it isn't finished. Note that cancellation is a best-effort policy and work that is already executing may continue to run. Upon cancellation, ListenableWorker.onStopped() will be invoked for any affected workers.

Parameters
`id`	`UUID`: The id of the work

Returns
`Operation`	An `Operation` that can be used to determine when the cancelWorkById has completed

enqueue

public final Operation enqueue (WorkRequest workRequest)

Enqueues one or more items for background processing.

Parameters
`workRequest`	`WorkRequest`: One or more `WorkRequest` to enqueue

Returns
`Operation`	An `Operation` that can be used to determine when the enqueue has completed

enqueue

public abstract Operation enqueue (List<? extends WorkRequest> requests)

Enqueues one or more items for background processing.

Parameters
`requests`	`List`: One or more `WorkRequest` to enqueue

Returns
`Operation`	An `Operation` that can be used to determine when the enqueue has completed

enqueueUniquePeriodicWork

public abstract Operation enqueueUniquePeriodicWork (String uniqueWorkName, 
                ExistingPeriodicWorkPolicy existingPeriodicWorkPolicy, 
                PeriodicWorkRequest periodicWork)

This method allows you to enqueue a uniquely-named PeriodicWorkRequest, where only one PeriodicWorkRequest of a particular name can be active at a time. For example, you may only want one sync operation to be active. If there is one pending, you can choose to let it run or replace it with your new work.

The uniqueWorkName uniquely identifies this PeriodicWorkRequest.

Parameters
`uniqueWorkName`	`String`: A unique name which for this operation
`existingPeriodicWorkPolicy`	`ExistingPeriodicWorkPolicy`: An `ExistingPeriodicWorkPolicy`
`periodicWork`	`PeriodicWorkRequest`: A `PeriodicWorkRequest` to enqueue. `REPLACE` ensures that if there is pending work labelled with `uniqueWorkName`, it will be cancelled and the new work will run. `KEEP` will run the new PeriodicWorkRequest only if there is no pending work labelled with `uniqueWorkName`.

Returns
`Operation`	An `Operation` that can be used to determine when the enqueue has completed

enqueueUniqueWork

public Operation enqueueUniqueWork (String uniqueWorkName, 
                ExistingWorkPolicy existingWorkPolicy, 
                OneTimeWorkRequest work)

This method allows you to enqueue work requests to a uniquely-named WorkContinuation, where only one continuation of a particular name can be active at a time. For example, you may only want one sync operation to be active. If there is one pending, you can choose to let it run or replace it with your new work.

The uniqueWorkName uniquely identifies this WorkContinuation.

Parameters
`uniqueWorkName`	`String`: A unique name which for this operation
`existingWorkPolicy`	`ExistingWorkPolicy`: An `ExistingWorkPolicy`; see below for more information
`work`	`OneTimeWorkRequest`: The `OneTimeWorkRequest`s to enqueue. `REPLACE` ensures that if there is pending work labelled with `uniqueWorkName`, it will be cancelled and the new work will run. `KEEP` will run the new OneTimeWorkRequests only if there is no pending work labelled with `uniqueWorkName`. `APPEND` will append the OneTimeWorkRequests as leaf nodes labelled with `uniqueWorkName`.

Returns
`Operation`	An `Operation` that can be used to determine when the enqueue has completed

enqueueUniqueWork

public abstract Operation enqueueUniqueWork (String uniqueWorkName, 
                ExistingWorkPolicy existingWorkPolicy, 
                List<OneTimeWorkRequest> work)

The uniqueWorkName uniquely identifies this WorkContinuation.

Parameters
`uniqueWorkName`	`String`: A unique name which for this operation
`existingWorkPolicy`	`ExistingWorkPolicy`: An `ExistingWorkPolicy`
`work`	`List`: `OneTimeWorkRequest`s to enqueue. `REPLACE` ensures that if there is pending work labelled with `uniqueWorkName`, it will be cancelled and the new work will run. `KEEP` will run the new OneTimeWorkRequests only if there is no pending work labelled with `uniqueWorkName`. `APPEND` will append the OneTimeWorkRequests as leaf nodes labelled with `uniqueWorkName`.

Returns
`Operation`	An `Operation` that can be used to determine when the enqueue has completed

getInstance

public static WorkManager getInstance ()

Retrieves the default singleton instance of WorkManager.

Returns
`WorkManager`	The singleton instance of `WorkManager`; this may be `null` in unusual circumstances where you have disabled automatic initialization and have failed to manually call `initialize(Context, Configuration)`.

Throws
`IllegalStateException`	If WorkManager is not initialized properly. This is most likely because you disabled the automatic initialization but forgot to manually call `initialize(Context, Configuration)`.

getLastCancelAllTimeMillis

public abstract ListenableFuture<Long> getLastCancelAllTimeMillis ()

Gets a ListenableFuture of the last time all work was cancelled. This method is intended for use by library and module developers who have dependent data in their own repository that must be updated or deleted in case someone cancels their work without their prior knowledge.

Returns
`ListenableFuture<Long>`	A `ListenableFuture` of the timestamp (`System#getCurrentTimeMillis()`) when `cancelAllWork()` was last invoked; this timestamp may be `0L` if this never occurred

getLastCancelAllTimeMillisLiveData

public abstract LiveData<Long> getLastCancelAllTimeMillisLiveData ()

Gets a LiveData of the last time all work was cancelled. This method is intended for use by library and module developers who have dependent data in their own repository that must be updated or deleted in case someone cancels their work without their prior knowledge.

Returns
`LiveData<Long>`	A `LiveData` of the timestamp (`System#getCurrentTimeMillis()`) when `cancelAllWork()` was last invoked; this timestamp may be `0L` if this never occurred

getWorkInfoById

public abstract ListenableFuture<WorkInfo> getWorkInfoById (UUID id)

Gets a ListenableFuture of the WorkInfo for a given work id.

Parameters
`id`	`UUID`: The id of the work

Returns
`ListenableFuture<WorkInfo>`	A `ListenableFuture` of the `WorkInfo` associated with `id`; note that this `WorkInfo` may be `null` if `id` is not known to WorkManager

getWorkInfoByIdLiveData

public abstract LiveData<WorkInfo> getWorkInfoByIdLiveData (UUID id)

Gets a LiveData of the WorkInfo for a given work id.

Parameters
`id`	`UUID`: The id of the work

Returns
`LiveData<WorkInfo>`	A `LiveData` of the `WorkInfo` associated with `id`; note that this `WorkInfo` may be `null` if `id` is not known to WorkManager.

getWorkInfosByTag

public abstract ListenableFuture<List<WorkInfo>> getWorkInfosByTag (String tag)

Gets a ListenableFuture of the WorkInfo for all work for a given tag.

Parameters
`tag`	`String`: The tag of the work

Returns
`ListenableFuture<List<WorkInfo>>`	A `ListenableFuture` list of `WorkInfo` for work tagged with `tag`

getWorkInfosByTagLiveData

public abstract LiveData<List<WorkInfo>> getWorkInfosByTagLiveData (String tag)

Gets a LiveData of the WorkInfo for all work for a given tag.

Parameters
`tag`	`String`: The tag of the work

Returns
`LiveData<List<WorkInfo>>`	A `LiveData` list of `WorkInfo` for work tagged with `tag`

getWorkInfosForUniqueWork

public abstract ListenableFuture<List<WorkInfo>> getWorkInfosForUniqueWork (String uniqueWorkName)

Gets a ListenableFuture of the WorkInfo for all work in a work chain with a given unique name.

Parameters
`uniqueWorkName`	`String`: The unique name used to identify the chain of work

Returns
`ListenableFuture<List<WorkInfo>>`	A `ListenableFuture` of the `WorkInfo` for work in the chain named `uniqueWorkName`

getWorkInfosForUniqueWorkLiveData

public abstract LiveData<List<WorkInfo>> getWorkInfosForUniqueWorkLiveData (String uniqueWorkName)

Gets a LiveData of the WorkInfo for all work in a work chain with a given unique name.

Parameters
`uniqueWorkName`	`String`: The unique name used to identify the chain of work

Returns
`LiveData<List<WorkInfo>>`	A `LiveData` of the `WorkInfo` for work in the chain named `uniqueWorkName`

initialize

public static void initialize (Context context, 
                Configuration configuration)

Used to do a one-time initialization of the WorkManager singleton with a custom Configuration. By default, this method should not be called because WorkManager is automatically initialized. To initialize WorkManager yourself, please follow these steps:

Disable androidx.work.impl.WorkManagerInitializer in your manifest.
Invoke this method in Application#onCreate or a ContentProvider. Note that this method must be invoked in one of these two places or you risk getting a NullPointerException in getInstance().

This method throws an exception if it is called multiple times.

Parameters
`context`	`Context`: A `Context` object for configuration purposes. Internally, this class will call `Context.getApplicationContext()`, so you may safely pass in any Context without risking a memory leak.
`configuration`	`Configuration`: The `Configuration` for used to set up WorkManager.

pruneWork

public abstract Operation pruneWork ()

Prunes all eligible finished work from the internal database. Eligible work must be finished (WorkInfo.State.SUCCEEDED, WorkInfo.State.FAILED, or WorkInfo.State.CANCELLED), with zero unfinished dependents.

Use this method with caution; by invoking it, you (and any modules and libraries in your codebase) will no longer be able to observe the WorkInfo of the pruned work. You do not normally need to call this method - WorkManager takes care to auto-prune its work after a sane period of time. This method also ignores the WorkRequest.Builder.keepResultsForAtLeast(long, TimeUnit) policy.

Returns
`Operation`	An `Operation` that can be used to determine when the pruneWork has completed

WorkManager

Summary

Public methods

Inherited methods

Public methods

beginUniqueWork

beginUniqueWork

beginWith

beginWith

cancelAllWork

cancelAllWorkByTag

cancelUniqueWork

cancelWorkById

enqueue

enqueue

enqueueUniquePeriodicWork

enqueueUniqueWork

enqueueUniqueWork

getInstance

getLastCancelAllTimeMillis

getLastCancelAllTimeMillisLiveData

getWorkInfoById

getWorkInfoByIdLiveData

getWorkInfosByTag

getWorkInfosByTagLiveData

getWorkInfosForUniqueWork

getWorkInfosForUniqueWorkLiveData

initialize

pruneWork

Interfaces

Classes

Enums