Service
abstract class Service : ContextWrapper, ComponentCallbacks2
kotlin.Any | |||
↳ | android.content.Context | ||
↳ | android.content.ContextWrapper | ||
↳ | android.app.Service |
A Service is an application component representing either an application's desire to perform a longer-running operation while not interacting with the user or to supply functionality for other applications to use. Each service class must have a corresponding <service>
declaration in its package's AndroidManifest.xml
. Services can be started with Context.startService()
and android.content.Context#bindService.
Note that services, like other application objects, run in the main thread of their hosting process. This means that, if your service is going to do any CPU intensive (such as MP3 playback) or blocking (such as networking) operations, it should spawn its own thread in which to do that work. More information on this can be found in Processes and Threads. The androidx.core.app.JobIntentService class is available as a standard implementation of Service that has its own thread where it schedules its work to be done.
Topics covered here:
- What is a Service?
- Service Lifecycle
- Permissions
- Process Lifecycle
- Local Service Sample
- Remote Messenger Service Sample
What is a Service?
Most confusion about the Service class actually revolves around what it is not:
- A Service is not a separate process. The Service object itself does not imply it is running in its own process; unless otherwise specified, it runs in the same process as the application it is part of.
- A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).
Thus a Service itself is actually very simple, providing two main features:
- A facility for the application to tell the system about something it wants to be doing in the background (even when the user is not directly interacting with the application). This corresponds to calls to
Context.startService()
, which ask the system to schedule work for the service, to be run until the service or someone else explicitly stop it. - A facility for an application to expose some of its functionality to other applications. This corresponds to calls to android.content.Context#bindService, which allows a long-standing connection to be made to the service in order to interact with it.
When a Service component is actually created, for either of these reasons, all that the system actually does is instantiate the component and call its onCreate
and any other appropriate callbacks on the main thread. It is up to the Service to implement these with the appropriate behavior, such as creating a secondary thread in which it does its work.
Note that because Service itself is so simple, you can make your interaction with it as simple or complicated as you want: from treating it as a local Java object that you make direct method calls on (as illustrated by Local Service Sample), to providing a full remoteable interface using AIDL.
Service Lifecycle
There are two reasons that a service can be run by the system. If someone calls Context.startService()
then the system will retrieve the service (creating it and calling its onCreate
method if needed) and then call its onStartCommand
method with the arguments supplied by the client. The service will at this point continue running until Context.stopService()
or stopSelf()
is called. Note that multiple calls to Context.startService() do not nest (though they do result in multiple corresponding calls to onStartCommand()), so no matter how many times it is started a service will be stopped once Context.stopService() or stopSelf() is called; however, services can use their stopSelf(int)
method to ensure the service is not stopped until started intents have been processed.
For started services, there are two additional major modes of operation they can decide to run in, depending on the value they return from onStartCommand(): START_STICKY
is used for services that are explicitly started and stopped as needed, while START_NOT_STICKY
or START_REDELIVER_INTENT
are used for services that should only remain running while processing any commands sent to them. See the linked documentation for more detail on the semantics.
Clients can also use android.content.Context#bindService to obtain a persistent connection to a service. This likewise creates the service if it is not already running (calling onCreate
while doing so), but does not call onStartCommand(). The client will receive the android.os.IBinder
object that the service returns from its onBind
method, allowing the client to then make calls back to the service. The service will remain running as long as the connection is established (whether or not the client retains a reference on the service's IBinder). Usually the IBinder returned is for a complex interface that has been written in aidl.
A service can be both started and have connections bound to it. In such a case, the system will keep the service running as long as either it is started or there are one or more connections to it with the Context.BIND_AUTO_CREATE
flag. Once neither of these situations hold, the service's onDestroy
method is called and the service is effectively terminated. All cleanup (stopping threads, unregistering receivers) should be complete upon returning from onDestroy().
Permissions
Global access to a service can be enforced when it is declared in its manifest's <service>
tag. By doing so, other applications will need to declare a corresponding <uses-permission>
element in their own manifest to be able to start, stop, or bind to the service.
As of android.os.Build.VERSION_CODES#GINGERBREAD
, when using Context.startService(Intent)
, you can also set Intent.FLAG_GRANT_READ_URI_PERMISSION
and/or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
on the Intent. This will grant the Service temporary access to the specific URIs in the Intent. Access will remain until the Service has called stopSelf(int)
for that start command or a later one, or until the Service has been completely stopped. This works for granting access to the other apps that have not requested the permission protecting the Service, or even when the Service is not exported at all.
In addition, a service can protect individual IPC calls into it with permissions, by calling the checkCallingPermission
method before executing the implementation of that call.
See the Security and Permissions document for more information on permissions and security in general.
Process Lifecycle
The Android system will attempt to keep the process hosting a service around as long as the service has been started or has clients bound to it. When running low on memory and needing to kill existing processes, the priority of a process hosting the service will be the higher of the following possibilities:
- If the service is currently executing code in its
onCreate()
,onStartCommand()
, oronDestroy()
methods, then the hosting process will be a foreground process to ensure this code can execute without being killed. - If the service has been started, then its hosting process is considered to be less important than any processes that are currently visible to the user on-screen, but more important than any process not visible. Because only a few processes are generally visible to the user, this means that the service should not be killed except in low memory conditions. However, since the user is not directly aware of a background service, in that state it is considered a valid candidate to kill, and you should be prepared for this to happen. In particular, long-running services will be increasingly likely to kill and are guaranteed to be killed (and restarted if appropriate) if they remain started long enough.
- If there are clients bound to the service, then the service's hosting process is never less important than the most important client. That is, if one of its clients is visible to the user, then the service itself is considered to be visible. The way a client's importance impacts the service's importance can be adjusted through
Context.BIND_ABOVE_CLIENT
,Context.BIND_ALLOW_OOM_MANAGEMENT
,Context.BIND_WAIVE_PRIORITY
,Context.BIND_IMPORTANT
, andContext.BIND_ADJUST_WITH_ACTIVITY
. - A started service can use the
startForeground(int,android.app.Notification)
API to put the service in a foreground state, where the system considers it to be something the user is actively aware of and thus not a candidate for killing when low on memory. (It is still theoretically possible for the service to be killed under extreme memory pressure from the current foreground application, but in practice this should not be a concern.)
Note this means that most of the time your service is running, it may be killed by the system if it is under heavy memory pressure. If this happens, the system will later try to restart the service. An important consequence of this is that if you implement onStartCommand()
to schedule work to be done asynchronously or in another thread, then you may want to use START_FLAG_REDELIVERY
to have the system re-deliver an Intent for you so that it does not get lost if your service is killed while processing it.
Other application components running in the same process as the service (such as an android.app.Activity
) can, of course, increase the importance of the overall process beyond just the importance of the service itself.
Local Service Sample
One of the most common uses of a Service is as a secondary component running alongside other parts of an application, in the same process as the rest of the components. All components of an .apk run in the same process unless explicitly stated otherwise, so this is a typical situation.
When used in this way, by assuming the components are in the same process, you can greatly simplify the interaction between them: clients of the service can simply cast the IBinder they receive from it to a concrete class published by the service.
An example of this use of a Service is shown here. First is the Service itself, publishing a custom class when bound:
With that done, one can now write client code that directly accesses the running service, such as:
Remote Messenger Service Sample
If you need to be able to write a Service that can perform complicated communication with clients in remote processes (beyond simply the use of Context.startService
to send commands to it), then you can use the android.os.Messenger
class instead of writing full AIDL files.
An example of a Service that uses Messenger as its client interface is shown here. First is the Service itself, publishing a Messenger to an internal Handler when bound:
If we want to make this service run in a remote process (instead of the standard one for its .apk), we can use android:process
in its manifest tag to specify one:
Note that the name "remote" chosen here is arbitrary, and you can use other names if you want additional processes. The ':' prefix appends the name to your package's standard process name.
With that done, clients can now bind to the service and send messages to it. Note that this allows clients to register with it to receive messages back as well:
Summary
Constants | |
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static Int |
Bits returned by |
static Int |
This flag is set in |
static Int |
This flag is set in |
static Int |
Constant to return from |
static Int |
Constant to return from |
static Int |
Constant to return from |
static Int |
Constant to return from |
static Int |
Selector for |
static Int |
Selector for |
static Int |
Selector for |
Inherited constants | |
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Public constructors | |
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Service() |
Public methods | |
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Application! |
Return the application that owns this service. |
Int |
If the service has become a foreground service by calling |
abstract IBinder? |
Return the communication channel to the service. |
open Unit |
onConfigurationChanged(newConfig: Configuration) |
open Unit |
onCreate() Called by the system when the service is first created. |
open Unit |
Called by the system to notify a Service that it is no longer used and is being removed. |
open Unit | |
open Unit |
Called when new clients have connected to the service, after it had previously been notified that all had disconnected in its |
open Unit | |
open Int |
onStartCommand(intent: Intent!, flags: Int, startId: Int) Called by the system every time a client explicitly starts the service by calling |
open Unit |
onTaskRemoved(rootIntent: Intent!) This is called if the service is currently running and the user has removed a task that comes from the service's application. |
open Unit |
Callback called on timeout for |
open Unit |
Callback called when a particular foreground service type has timed out. |
open Unit |
onTrimMemory(level: Int) |
open Boolean |
Called when all clients have disconnected from a particular interface published by the service. |
Unit |
startForeground(id: Int, notification: Notification!) If your service is started (running through |
Unit |
startForeground(id: Int, notification: Notification, foregroundServiceType: Int) An overloaded version of |
Unit |
stopForeground(removeNotification: Boolean) Legacy version of |
Unit |
stopForeground(notificationBehavior: Int) Remove this service from foreground state, allowing it to be killed if more memory is needed. |
Unit |
stopSelf() Stop the service, if it was previously started. |
Unit |
Old version of |
Boolean |
stopSelfResult(startId: Int) Stop the service if the most recent time it was started was startId. |
Protected methods | |
---|---|
open Unit |
attachBaseContext(newBase: Context!) |
open Unit |
dump(fd: FileDescriptor!, writer: PrintWriter!, args: Array<String!>!) Print the Service's state into the given stream. |
Inherited functions | |
---|---|
Constants
START_CONTINUATION_MASK
static val START_CONTINUATION_MASK: Int
Bits returned by onStartCommand
describing how to continue the service if it is killed. May be START_STICKY
, START_NOT_STICKY
, START_REDELIVER_INTENT
, or START_STICKY_COMPATIBILITY
.
Value: 15
START_FLAG_REDELIVERY
static val START_FLAG_REDELIVERY: Int
This flag is set in onStartCommand
if the Intent is a re-delivery of a previously delivered intent, because the service had previously returned START_REDELIVER_INTENT
but had been killed before calling stopSelf(int)
for that Intent.
Value: 1
START_FLAG_RETRY
static val START_FLAG_RETRY: Int
This flag is set in onStartCommand
if the Intent is a retry because the original attempt never got to or returned from onStartCommand(android.content.Intent,int,int)
.
Value: 2
START_NOT_STICKY
static val START_NOT_STICKY: Int
Constant to return from onStartCommand
: if this service's process is killed while it is started (after returning from onStartCommand
), and there are no new start intents to deliver to it, then take the service out of the started state and don't recreate until a future explicit call to Context.startService(Intent)
. The service will not receive a onStartCommand(android.content.Intent,int,int)
call with a null Intent because it will not be restarted if there are no pending Intents to deliver.
This mode makes sense for things that want to do some work as a result of being started, but can be stopped when under memory pressure and will explicit start themselves again later to do more work. An example of such a service would be one that polls for data from a server: it could schedule an alarm to poll every N minutes by having the alarm start its service. When its onStartCommand
is called from the alarm, it schedules a new alarm for N minutes later, and spawns a thread to do its networking. If its process is killed while doing that check, the service will not be restarted until the alarm goes off.
Value: 2
START_REDELIVER_INTENT
static val START_REDELIVER_INTENT: Int
Constant to return from onStartCommand
: if this service's process is killed while it is started (after returning from onStartCommand
), then it will be scheduled for a restart and the last delivered Intent re-delivered to it again via onStartCommand
. This Intent will remain scheduled for redelivery until the service calls stopSelf(int)
with the start ID provided to onStartCommand
. The service will not receive a onStartCommand(android.content.Intent,int,int)
call with a null Intent because it will only be restarted if it is not finished processing all Intents sent to it (and any such pending events will be delivered at the point of restart).
Value: 3
START_STICKY
static val START_STICKY: Int
Constant to return from onStartCommand
: if this service's process is killed while it is started (after returning from onStartCommand
), then leave it in the started state but don't retain this delivered intent. Later the system will try to re-create the service. Because it is in the started state, it will guarantee to call onStartCommand
after creating the new service instance; if there are not any pending start commands to be delivered to the service, it will be called with a null intent object, so you must take care to check for this.
This mode makes sense for things that will be explicitly started and stopped to run for arbitrary periods of time, such as a service performing background music playback.
Since Android version Build.VERSION_CODES.S
, apps targeting Build.VERSION_CODES.S
or above are disallowed to start a foreground service from the background, but the restriction doesn't impact restarts of a sticky foreground service. However, when apps start a sticky foreground service from the background, the same restriction still applies.
Value: 1
START_STICKY_COMPATIBILITY
static val START_STICKY_COMPATIBILITY: Int
Constant to return from onStartCommand
: compatibility version of START_STICKY
that does not guarantee that onStartCommand
will be called again after being killed.
Value: 0
STOP_FOREGROUND_DETACH
static val STOP_FOREGROUND_DETACH: Int
Selector for stopForeground(int)
: if set, the notification previously supplied to #startForeground will be detached from the service's lifecycle. The notification will remain shown even after the service is stopped and destroyed.
Value: 2
STOP_FOREGROUND_LEGACY
static valSTOP_FOREGROUND_LEGACY: Int
Deprecated: Use STOP_FOREGROUND_DETACH
instead. The legacy behavior was inconsistent, leading to bugs around unpredictable results.
Selector for stopForeground(int)
: equivalent to passing false
to the legacy API stopForeground(boolean)
.
Value: 0
STOP_FOREGROUND_REMOVE
static val STOP_FOREGROUND_REMOVE: Int
Selector for stopForeground(int)
: if supplied, the notification previously supplied to #startForeground will be cancelled and removed from display.
Value: 1
Public constructors
Public methods
getApplication
fun getApplication(): Application!
Return the application that owns this service.
getForegroundServiceType
fun getForegroundServiceType(): Int
If the service has become a foreground service by calling startForeground(int,android.app.Notification)
or startForeground(int,android.app.Notification,int)
, getForegroundServiceType()
returns the current foreground service type.
If there is no foregroundServiceType specified in manifest, ServiceInfo.FOREGROUND_SERVICE_TYPE_NONE
is returned.
If the service is not a foreground service, ServiceInfo.FOREGROUND_SERVICE_TYPE_NONE
is returned.
onBind
abstract fun onBind(intent: Intent!): IBinder?
Return the communication channel to the service. May return null if clients can not bind to the service. The returned android.os.IBinder
is usually for a complex interface that has been described using aidl.
Note that unlike other application components, calls on to the IBinder interface returned here may not happen on the main thread of the process. More information about the main thread can be found in Processes and Threads.
Parameters | |
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intent |
Intent!: The Intent that was used to bind to this service, as given to android.content.Context#bindService. Note that any extras that were included with the Intent at that point will not be seen here. |
Return | |
---|---|
IBinder? |
Return an IBinder through which clients can call on to the service. |
onConfigurationChanged
open fun onConfigurationChanged(newConfig: Configuration): Unit
Parameters | |
---|---|
newConfig |
Configuration: The new device configuration. This value cannot be null . |
onCreate
open fun onCreate(): Unit
Called by the system when the service is first created. Do not call this method directly.
onDestroy
open fun onDestroy(): Unit
Called by the system to notify a Service that it is no longer used and is being removed. The service should clean up any resources it holds (threads, registered receivers, etc) at this point. Upon return, there will be no more calls in to this Service object and it is effectively dead. Do not call this method directly.
onRebind
open fun onRebind(intent: Intent!): Unit
Called when new clients have connected to the service, after it had previously been notified that all had disconnected in its onUnbind
. This will only be called if the implementation of onUnbind
was overridden to return true.
Parameters | |
---|---|
intent |
Intent!: The Intent that was used to bind to this service, as given to android.content.Context#bindService. Note that any extras that were included with the Intent at that point will not be seen here. |
onStart
open funonStart(
intent: Intent!,
startId: Int
): Unit
Deprecated: Implement onStartCommand(android.content.Intent,int,int)
instead.
onStartCommand
open fun onStartCommand(
intent: Intent!,
flags: Int,
startId: Int
): Int
Called by the system every time a client explicitly starts the service by calling android.content.Context#startService
, providing the arguments it supplied and a unique integer token representing the start request. Do not call this method directly.
For backwards compatibility, the default implementation calls onStart
and returns either START_STICKY
or START_STICKY_COMPATIBILITY
.
Note that the system calls this on your service's main thread. A service's main thread is the same thread where UI operations take place for Activities running in the same process. You should always avoid stalling the main thread's event loop. When doing long-running operations, network calls, or heavy disk I/O, you should kick off a new thread, or use android.os.AsyncTask
.
Parameters | |
---|---|
intent |
Intent!: The Intent supplied to android.content.Context#startService , as given. This may be null if the service is being restarted after its process has gone away, and it had previously returned anything except START_STICKY_COMPATIBILITY . |
flags |
Int: Additional data about this start request. Value is either 0 or a combination of android.app.Service#START_FLAG_REDELIVERY , and android.app.Service#START_FLAG_RETRY |
startId |
Int: A unique integer representing this specific request to start. Use with stopSelfResult(int) . |
Return | |
---|---|
Int |
The return value indicates what semantics the system should use for the service's current started state. It may be one of the constants associated with the START_CONTINUATION_MASK bits. Value is android.app.Service#START_STICKY_COMPATIBILITY , android.app.Service#START_STICKY , android.app.Service#START_NOT_STICKY , or android.app.Service#START_REDELIVER_INTENT |
See Also
onTaskRemoved
open fun onTaskRemoved(rootIntent: Intent!): Unit
This is called if the service is currently running and the user has removed a task that comes from the service's application. If you have set ServiceInfo.FLAG_STOP_WITH_TASK
then you will not receive this callback; instead, the service will simply be stopped.
Parameters | |
---|---|
rootIntent |
Intent!: The original root Intent that was used to launch the task that is being removed. |
onTimeout
open fun onTimeout(startId: Int): Unit
Callback called on timeout for ServiceInfo.FOREGROUND_SERVICE_TYPE_SHORT_SERVICE
. See ServiceInfo.FOREGROUND_SERVICE_TYPE_SHORT_SERVICE
for more details.
If the foreground service of type ServiceInfo.FOREGROUND_SERVICE_TYPE_SHORT_SERVICE
doesn't finish even after it's timed out, the app will be declared an ANR after a short grace period of several seconds.
Starting from Android version android.os.Build.VERSION_CODES#VANILLA_ICE_CREAM
, onTimeout(int,int)
will also be called when a foreground service of type ServiceInfo.FOREGROUND_SERVICE_TYPE_SHORT_SERVICE
times out. Developers do not need to implement both of the callbacks on android.os.Build.VERSION_CODES#VANILLA_ICE_CREAM
and onwards.
Note, even though ServiceInfo.FOREGROUND_SERVICE_TYPE_SHORT_SERVICE
was added on Android version android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE
, it can be also used on on prior android versions (just like other new foreground service types can be used). However, because android.app.Service#onTimeout(int)
did not exist on prior versions, it will never called on such versions. Because of this, developers must make sure to stop the foreground service even if android.app.Service#onTimeout(int)
is not called on such versions.
Parameters | |
---|---|
startId |
Int: the startId passed to onStartCommand(android.content.Intent,int,int) when the service started. |
onTimeout
open fun onTimeout(
startId: Int,
fgsType: Int
): Unit
Callback called when a particular foreground service type has timed out.
This callback is meant to give the app a small grace period of a few seconds to finish the foreground service of the associated type - if it fails to do so, the app will crash.
The foreground service of the associated type can be stopped within the time limit by android.app.Service#stopSelf()
, android.content.Context#stopService(android.content.Intent)
or their overloads. android.app.Service#stopForeground(int)
can be used as well, which demotes the service to a "background" service, which will soon be stopped by the system.
The specific time limit for each type (if one exists) is mentioned in the documentation for that foreground service type. See dataSync
for example.
Note: time limits are restricted to a rolling 24-hour window - for example, if a foreground service type has a time limit of 6 hours, that time counter begins as soon as the foreground service starts. This time limit will only be reset once every 24 hours or if the app comes into the foreground state.
onTrimMemory
open fun onTrimMemory(level: Int): Unit
Parameters | |
---|---|
level |
Int: The context of the trim, giving a hint of the amount of trimming the application may like to perform. Value is android.content.ComponentCallbacks2#TRIM_MEMORY_COMPLETE , android.content.ComponentCallbacks2#TRIM_MEMORY_MODERATE , android.content.ComponentCallbacks2#TRIM_MEMORY_BACKGROUND , android.content.ComponentCallbacks2#TRIM_MEMORY_UI_HIDDEN , android.content.ComponentCallbacks2#TRIM_MEMORY_RUNNING_CRITICAL , android.content.ComponentCallbacks2#TRIM_MEMORY_RUNNING_LOW , or android.content.ComponentCallbacks2#TRIM_MEMORY_RUNNING_MODERATE |
onUnbind
open fun onUnbind(intent: Intent!): Boolean
Called when all clients have disconnected from a particular interface published by the service. The default implementation does nothing and returns false.
Parameters | |
---|---|
intent |
Intent!: The Intent that was used to bind to this service, as given to android.content.Context#bindService. Note that any extras that were included with the Intent at that point will not be seen here. |
Return | |
---|---|
Boolean |
Return true if you would like to have the service's onRebind method later called when new clients bind to it. |
startForeground
fun startForeground(
id: Int,
notification: Notification!
): Unit
If your service is started (running through Context.startService(Intent)
), then also make this service run in the foreground, supplying the ongoing notification to be shown to the user while in this state. By default started services are background, meaning that their process won't be given foreground CPU scheduling (unless something else in that process is foreground) and, if the system needs to kill them to reclaim more memory (such as to display a large page in a web browser), they can be killed without too much harm. You use #startForeground if killing your service would be disruptive to the user, such as if your service is performing background music playback, so the user would notice if their music stopped playing.
Note that calling this method does not put the service in the started state itself, even though the name sounds like it. You must always call startService(android.content.Intent)
first to tell the system it should keep the service running, and then use this method to tell it to keep it running harder.
Apps targeting API android.os.Build.VERSION_CODES#P
or later must request the permission android.Manifest.permission#FOREGROUND_SERVICE
in order to use this API.
Apps built with SDK version android.os.Build.VERSION_CODES#Q
or later can specify the foreground service types using attribute android.R.attr#foregroundServiceType
in service element of manifest file. The value of attribute android.R.attr#foregroundServiceType
can be multiple flags ORed together.
Note: Beginning with SDK Version android.os.Build.VERSION_CODES#S
, apps targeting SDK Version android.os.Build.VERSION_CODES#S
or higher are not allowed to start foreground services from the background. See Behavior changes: Apps targeting Android 12 for more details.
Note: Beginning with SDK Version android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE
, apps targeting SDK Version android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE
or higher are not allowed to start foreground services without specifying a valid foreground service type in the manifest attribute android.R.attr#foregroundServiceType
. See Behavior changes: Apps targeting Android 14 for more details.
Parameters | |
---|---|
id |
Int: The identifier for this notification as per NotificationManager.notify(int, Notification) ; must not be 0. |
notification |
Notification!: The Notification to be displayed. |
Exceptions | |
---|---|
android.app.ForegroundServiceStartNotAllowedException |
If the app targeting API is android.os.Build.VERSION_CODES#S or later, and the service is restricted from becoming foreground service due to background restriction. |
android.app.InvalidForegroundServiceTypeException |
If the app targeting API is android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE or later, and the manifest attribute android.R.attr#foregroundServiceType is set to invalid types(i.e. ServiceInfo.FOREGROUND_SERVICE_TYPE_NONE ). |
android.app.MissingForegroundServiceTypeException |
If the app targeting API is android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE or later, and the manifest attribute android.R.attr#foregroundServiceType is not set. |
java.lang.SecurityException |
If the app targeting API is android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE or later and doesn't have the permission to start the foreground service with the specified type in the manifest attribute android.R.attr#foregroundServiceType . |
See Also
startForeground
fun startForeground(
id: Int,
notification: Notification,
foregroundServiceType: Int
): Unit
An overloaded version of startForeground(int,android.app.Notification)
with additional foregroundServiceType parameter.
Apps built with SDK version android.os.Build.VERSION_CODES#Q
or later can specify the foreground service types using attribute android.R.attr#foregroundServiceType
in service element of manifest file. The value of attribute android.R.attr#foregroundServiceType
can be multiple flags ORed together.
The foregroundServiceType parameter must be a subset flags of what is specified in manifest attribute android.R.attr#foregroundServiceType
, if not, an IllegalArgumentException is thrown. Specify foregroundServiceType parameter as android.content.pm.ServiceInfo#FOREGROUND_SERVICE_TYPE_MANIFEST
to use all flags that is specified in manifest attribute foregroundServiceType.
Note: Beginning with SDK Version android.os.Build.VERSION_CODES#S
, apps targeting SDK Version android.os.Build.VERSION_CODES#S
or higher are not allowed to start foreground services from the background. See Behavior changes: Apps targeting Android 12 for more details.
Note: Beginning with SDK Version android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE
, apps targeting SDK Version android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE
or higher are not allowed to start foreground services without specifying a valid foreground service type in the manifest attribute android.R.attr#foregroundServiceType
, and the parameter foregroundServiceType
here must not be the ServiceInfo.FOREGROUND_SERVICE_TYPE_NONE
. See Behavior changes: Apps targeting Android 14 for more details.
Exceptions | |
---|---|
java.lang.IllegalArgumentException |
if param foregroundServiceType is not subset of manifest attribute android.R.attr#foregroundServiceType . |
android.app.ForegroundServiceStartNotAllowedException |
If the app targeting API is android.os.Build.VERSION_CODES#S or later, and the service is restricted from becoming foreground service due to background restriction. |
android.app.InvalidForegroundServiceTypeException |
If the app targeting API is android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE or later, and the manifest attribute android.R.attr#foregroundServiceType or the param foregroundServiceType is set to invalid types(i.e.ServiceInfo.FOREGROUND_SERVICE_TYPE_NONE ). |
android.app.MissingForegroundServiceTypeException |
If the app targeting API is android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE or later, and the manifest attribute android.R.attr#foregroundServiceType is not set and the param foregroundServiceType is set to ServiceInfo.FOREGROUND_SERVICE_TYPE_MANIFEST . |
java.lang.SecurityException |
If the app targeting API is android.os.Build.VERSION_CODES#UPSIDE_DOWN_CAKE or later and doesn't have the permission to start the foreground service with the specified type in foregroundServiceType . android.R.attr#foregroundServiceType . |
stopForeground
funstopForeground(removeNotification: Boolean): Unit
Deprecated: call stopForeground(int)
and pass either STOP_FOREGROUND_REMOVE
or STOP_FOREGROUND_DETACH
explicitly instead.
Legacy version of stopForeground(int)
.
Parameters | |
---|---|
removeNotification |
Boolean: If true, the STOP_FOREGROUND_REMOVE selector will be passed to stopForeground(int) ; otherwise STOP_FOREGROUND_LEGACY will be passed. |
stopForeground
fun stopForeground(notificationBehavior: Int): Unit
Remove this service from foreground state, allowing it to be killed if more memory is needed. This does not stop the service from running (for that you use stopSelf()
or related methods), just takes it out of the foreground state.
If STOP_FOREGROUND_REMOVE
is supplied, the service's associated notification will be cancelled immediately.
If STOP_FOREGROUND_DETACH
is supplied, the service's association with the notification will be severed. If the notification had not yet been shown, due to foreground-service notification deferral policy, it is immediately posted when stopForeground(STOP_FOREGROUND_DETACH)
is called. In all cases, the notification remains shown even after this service is stopped fully and destroyed.
If zero
is passed as the argument, the result will be the legacy behavior as defined prior to Android L: the notification will remain posted until the service is fully stopped, at which time it will automatically be cancelled.
Parameters | |
---|---|
notificationBehavior |
Int: the intended behavior for the service's associated notification Value is android.app.Service#STOP_FOREGROUND_LEGACY , android.app.Service#STOP_FOREGROUND_REMOVE , or android.app.Service#STOP_FOREGROUND_DETACH |
stopSelf
fun stopSelf(): Unit
Stop the service, if it was previously started. This is the same as calling android.content.Context#stopService
for this particular service.
See Also
stopSelf
fun stopSelf(startId: Int): Unit
Old version of stopSelfResult
that doesn't return a result.
See Also
stopSelfResult
fun stopSelfResult(startId: Int): Boolean
Stop the service if the most recent time it was started was startId. This is the same as calling android.content.Context#stopService
for this particular service but allows you to safely avoid stopping if there is a start request from a client that you haven't yet seen in onStart
.
Be careful about ordering of your calls to this function.. If you call this function with the most-recently received ID before you have called it for previously received IDs, the service will be immediately stopped anyway. If you may end up processing IDs out of order (such as by dispatching them on separate threads), then you are responsible for stopping them in the same order you received them.
Parameters | |
---|---|
startId |
Int: The most recent start identifier received in onStart . |
Return | |
---|---|
Boolean |
Returns true if the startId matches the last start request and the service will be stopped, else false. |
See Also
Protected methods
attachBaseContext
protected open fun attachBaseContext(newBase: Context!): Unit
Parameters | |
---|---|
base |
The new base context for this wrapper. |
dump
protected open fun dump(
fd: FileDescriptor!,
writer: PrintWriter!,
args: Array<String!>!
): Unit
Print the Service's state into the given stream. This gets invoked if you run "adb shell dumpsys activity service <yourservicename>" (note that for this command to work, the service must be running, and you must specify a fully-qualified service name). This is distinct from "dumpsys <servicename>", which only works for named system services and which invokes the IBinder.dump
method on the IBinder
interface registered with ServiceManager.
Parameters | |
---|---|
fd |
FileDescriptor!: The raw file descriptor that the dump is being sent to. |
writer |
PrintWriter!: The PrintWriter to which you should dump your state. This will be closed for you after you return. |
args |
Array<String!>!: additional arguments to the dump request. |