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I want to know the difference between FutureTask and AsyncTask in android. According to my thinking we can get the current situation in FutureTask. Using ExecutorService we can create a pool of parallel processes. Same property we can achieve using AsyncTask . I want to know the situation where to use AsyncTask and when to use FutureTask.

I have asked a Question here but not getting any response . Now i think i should change my way of getting webservices data. So i think i should use FutureTask because they have function like isDone()

and cancel. Please some one guide me any better way to retrieve data from web-services. because my textView set's the adapter too slow.

Or simply i need a way to cancel the running AsyncTasks or replace it with the current. When user press w it call for the AsyncTask and when he added any word to it in AutotextView it will call thrice for waka one for wa and wak and one for waka . Is it possible to cancel the running task when user presses another text. See my Question here for Details.

Community
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Zar E Ahmer
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    Well they are as different as a river bank is to a capacitor bank. Two different classes whose purpose you could probably have worked out just by reading the docs: [FutureTask](http://developer.android.com/reference/java/util/concurrent/FutureTask.html), [AsyncTask](http://developer.android.com/reference/android/os/AsyncTask.html). – Mister Smith Jul 25 '14 at 08:09
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    I read both docs and still don't have a good idea when to use which. It seems I could always use a future task.... – clocksmith Mar 09 '16 at 21:35
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    @813951 "Read the docs" is an insult, not an answer. – Maarten Jan 31 '19 at 07:18

2 Answers2

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AsyncTask provides callbacks (onPreExecute, onProgressExecute, and onPostExecute) which are guaranteed to run on the UI thread. AsyncTask is deprecated (thanks chokdee).

FutureTask provides no callbacks and doesn't know anything about the Android UI thread. In fact, Android apps shouldn't call Future.get() from the UI thread, because it may block.

Android apps should use Kotlin coroutines. If you're stuck in Java, use FutureTask.

gladed
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Exception Handling:

if exception throw in AsyncTask.doInBackground, then this exception will rethrow as RuntimeException in AsyncTask threadpool thread(not UI thread commonly)

if exception throw in FutureTask.run, then this exception will be catched by FutureTask and rethrow when you call FutureTask.get()

isCancelled() invocation

in FutureTask.run can't invoke FutureTask.isCancelled(), but in AsyncTask.doInBackground can invoke AsyncTask.isCancelled()

Yessy
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