IntentService.javaAPI DocAndroid 5.1 API5959Thu Mar 12 22:22:10 GMT


public abstract class IntentService extends Service
IntentService is a base class for {@link Service}s that handle asynchronous requests (expressed as {@link Intent}s) on demand. Clients send requests through {@link android.content.Context#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 {@link #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.


Fields Summary
private volatile android.os.Looper
private volatile ServiceHandler
private String
private boolean
Constructors Summary
public IntentService(String name)
Creates an IntentService. Invoked by your subclass's constructor.

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

        mName = name;
Methods Summary
public android.os.IBinderonBind(android.content.Intent intent)
Unless you provide binding for your service, you don't need to implement this method, because the default implementation returns null.


        return null;
public voidonCreate()

        // TODO: It would be nice to have an option to hold a partial wakelock
        // during processing, and to have a static startService(Context, Intent)
        // method that would launch the service & hand off a wakelock.

        HandlerThread thread = new HandlerThread("IntentService[" + mName + "]");

        mServiceLooper = thread.getLooper();
        mServiceHandler = new ServiceHandler(mServiceLooper);
public voidonDestroy()

protected abstract voidonHandleIntent(android.content.Intent intent)
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 {@link #stopSelf}.

intent The value passed to {@link android.content.Context#startService(Intent)}.

public voidonStart(android.content.Intent intent, int startId)

        Message msg = mServiceHandler.obtainMessage();
        msg.arg1 = startId;
        msg.obj = intent;
public intonStartCommand(android.content.Intent intent, int flags, int startId)
You should not override this method for your IntentService. Instead, override {@link #onHandleIntent}, which the system calls when the IntentService receives a start request.


        onStart(intent, startId);
        return mRedelivery ? START_REDELIVER_INTENT : START_NOT_STICKY;
public voidsetIntentRedelivery(boolean enabled)
Sets intent redelivery preferences. Usually called from the constructor with your preferred semantics.

If enabled is true, {@link #onStartCommand(Intent, int, int)} will return {@link Service#START_REDELIVER_INTENT}, so if this process dies before {@link #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), {@link #onStartCommand(Intent, int, int)} will return {@link Service#START_NOT_STICKY}, and if the process dies, the Intent dies along with it.

        mRedelivery = enabled;