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Added in API level 3

public abstract class

IntentService

extends Service

java.lang.Object
↳	android.content.Context
	↳	android.content.ContextWrapper
		↳	android.app.Service
			↳	android.app.IntentService

Class Overview

IntentService is a base class for Service s that handle asynchronous requests (expressed as Intent s) on demand. Clients send requests through startService(Intent) calls; the service is started as needed, handles each Intent in turn using a worker thread, and stops itself when it runs out of work.

This "work queue processor" pattern is commonly used to offload tasks from an application's main thread. The IntentService class exists to simplify this pattern and take care of the mechanics. To use it, extend IntentService and implement onHandleIntent(Intent) . IntentService will receive the Intents, launch a worker thread, and stop the service as appropriate.

All requests are handled on a single worker thread -- they may take as long as necessary (and will not block the application's main loop), but only one request will be processed at a time.

Developer Guides

For a detailed discussion about how to create services, read the Services developer guide.

Summary

[Expand]

Inherited Constants

From class android.app.Service

From class android.content.Context

From interface android.content.ComponentCallbacks2

int	TRIM_MEMORY_BACKGROUND	Level for `onTrimMemory(int)` : the process has gone on to the LRU list.
int	TRIM_MEMORY_COMPLETE	Level for `onTrimMemory(int)` : the process is nearing the end of the background LRU list, and if more memory isn't found soon it will be killed.
int	TRIM_MEMORY_MODERATE	Level for `onTrimMemory(int)` : the process is around the middle of the background LRU list; freeing memory can help the system keep other processes running later in the list for better overall performance.
int	TRIM_MEMORY_RUNNING_CRITICAL	Level for `onTrimMemory(int)` : the process is not an expendable background process, but the device is running extremely low on memory and is about to not be able to keep any background processes running.
int	TRIM_MEMORY_RUNNING_LOW	Level for `onTrimMemory(int)` : the process is not an expendable background process, but the device is running low on memory.
int	TRIM_MEMORY_RUNNING_MODERATE	Level for `onTrimMemory(int)` : the process is not an expendable background process, but the device is running moderately low on memory.
int	TRIM_MEMORY_UI_HIDDEN	Level for `onTrimMemory(int)` : the process had been showing a user interface, and is no longer doing so.

Public Constructors
	IntentService ( String name) Creates an IntentService.

Public Methods
IBinder	onBind ( Intent intent) Unless you provide binding for your service, you don't need to implement this method, because the default implementation returns null.
void	onCreate () Called by the system when the service is first created.
void	onDestroy () Called by the system to notify a Service that it is no longer used and is being removed.
void	onStart ( Intent intent, int startId) This method is deprecated. Implement `onStartCommand(Intent, int, int)` instead.
int	onStartCommand ( Intent intent, int flags, int startId) You should not override this method for your IntentService.
void	setIntentRedelivery (boolean enabled) Sets intent redelivery preferences.

Protected Methods
abstract void	onHandleIntent ( Intent intent) This method is invoked on the worker thread with a request to process.

[Expand]

Inherited Methods

From class android.app.Service

void	dump ( FileDescriptor fd, PrintWriter writer, String[] args) Print the Service's state into the given stream.
final Application	getApplication () Return the application that owns this service.
abstract IBinder	onBind ( Intent intent) Return the communication channel to the service.
void	onConfigurationChanged ( Configuration newConfig) Called by the system when the device configuration changes while your component is running.
void	onCreate () Called by the system when the service is first created.
void	onDestroy () Called by the system to notify a Service that it is no longer used and is being removed.
void	onLowMemory () This is called when the overall system is running low on memory, and actively running processes should trim their memory usage.
void	onRebind ( Intent intent) Called when new clients have connected to the service, after it had previously been notified that all had disconnected in its `onUnbind(Intent)` .
void	onStart ( Intent intent, int startId) This method was deprecated in API level 5. Implement `onStartCommand(Intent, int, int)` instead.
int	onStartCommand ( Intent intent, int flags, int startId) Called by the system every time a client explicitly starts the service by calling `startService(Intent)` , providing the arguments it supplied and a unique integer token representing the start request.
void	onTaskRemoved ( Intent rootIntent) This is called if the service is currently running and the user has removed a task that comes from the service's application.
void	onTrimMemory (int level) Called when the operating system has determined that it is a good time for a process to trim unneeded memory from its process.
boolean	onUnbind ( Intent intent) Called when all clients have disconnected from a particular interface published by the service.
final void	startForeground (int id, Notification notification) Make this service run in the foreground, supplying the ongoing notification to be shown to the user while in this state.
final void	stopForeground (boolean removeNotification) Remove this service from foreground state, allowing it to be killed if more memory is needed.
final void	stopSelf () Stop the service, if it was previously started.
final void	stopSelf (int startId) Old version of `stopSelfResult(int)` that doesn't return a result.
final boolean	stopSelfResult (int startId) Stop the service if the most recent time it was started was `startId` .

From class android.content.ContextWrapper

From class android.content.Context

From class java.lang.Object

Object	clone () Creates and returns a copy of this `Object` .
boolean	equals ( Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize () Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class <?>	getClass () Returns the unique instance of `Class` that represents this object's class.
int	hashCode () Returns an integer hash code for this object.
final void	notify () Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll () Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString () Returns a string containing a concise, human-readable description of this object.
final void	wait () Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait (long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait (long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface android.content.ComponentCallbacks

From interface android.content.ComponentCallbacks2

Public Constructors

public IntentService ( String name)

Added in API level 3

Creates an IntentService. Invoked by your subclass's constructor.

Parameters

name	Used to name the worker thread, important only for debugging.

Public Methods

public IBinder onBind ( Intent intent)

Added in API level 3

Unless you provide binding for your service, you don't need to implement this method, because the default implementation returns null.

Parameters

intent	The Intent that was used to bind to this service, as given to `Context.bindService` . Note that any extras that were included with the Intent at that point will not be seen here.

Returns

Return an IBinder through which clients can call on to the service.

public void onCreate ()

Added in API level 3

Called by the system when the service is first created. Do not call this method directly.

public void onDestroy ()

Added in API level 3

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.

public void onStart ( Intent intent, int startId)

Added in API level 3

This method is deprecated.
Implement onStartCommand(Intent, int, int) instead.

public int onStartCommand ( Intent intent, int flags, int startId)

Added in API level 5

You should not override this method for your IntentService. Instead, override onHandleIntent(Intent) , which the system calls when the IntentService receives a start request.

Parameters

intent	The Intent supplied to `startService(Intent)` , 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	Additional data about this start request. Currently either 0, `START_FLAG_REDELIVERY` , or `START_FLAG_RETRY` .
startId	A unique integer representing this specific request to start. Use with `stopSelfResult(int)` .

Returns

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.

public void setIntentRedelivery (boolean enabled)

Added in API level 5

Sets intent redelivery preferences. Usually called from the constructor with your preferred semantics.

If enabled is true, onStartCommand(Intent, int, int) will return START_REDELIVER_INTENT , so if this process dies before onHandleIntent(Intent) returns, the process will be restarted and the intent redelivered. If multiple Intents have been sent, only the most recent one is guaranteed to be redelivered.

If enabled is false (the default), onStartCommand(Intent, int, int) will return START_NOT_STICKY , and if the process dies, the Intent dies along with it.

Protected Methods

protected abstract void onHandleIntent ( Intent intent)

Added in API level 3

This method is invoked on the worker thread with a request to process. Only one Intent is processed at a time, but the processing happens on a worker thread that runs independently from other application logic. So, if this code takes a long time, it will hold up other requests to the same IntentService, but it will not hold up anything else. When all requests have been handled, the IntentService stops itself, so you should not call stopSelf() .

Parameters

intent	The value passed to `startService(Intent)` .

Results

Interfaces

Classes

Exceptions

IntentService

Class Overview

Developer Guides

See Also

Summary

Public Constructors

public IntentService ( String name)

Parameters

Public Methods

public IBinder onBind ( Intent intent)

Parameters

Returns

See Also

public void onCreate ()

public void onDestroy ()

public void onStart ( Intent intent, int startId)

public int onStartCommand ( Intent intent, int flags, int startId)

Parameters

Returns

See Also

public void setIntentRedelivery (boolean enabled)

Protected Methods

protected abstract void onHandleIntent ( Intent intent)

Parameters