AsyncTask and error when executed twice

Question

I use an asynctask in my app that downloads some data from the internet. If this task is executed twice within seconds, user presses the button twice, I get an IllegalState error saying a task can not be execute twice. If the user waits about 30 seconds, everyting is fine.

Then I tried to use AsyncTask.getStatus(), like this, to only execute when the task was NOT RUNNING, ie executed when status was PENDING or FINISHED, but this only worked the first time when the getStatus() was PENDING. If it was FINISHED, the same IllegalState error was produced.

Then I tried to follow an other example, saying the a new object of the AsyncTask should be created each time it is supposed to be executed. This seems to work.

So my question is, is it not possible to use one instance of an asynctask object and reexecute it? If so, how come it can be done if you wait long enought (like 30 seconds)?

It is duplicate of that subject: http://stackoverflow.com/questions/6373826/execute-asynctask-several-times — Rambo's son, Dec 15 '15 at 19:31
Ahhhh.... There it is... Better create better search string next time... Thanx — user1086500, Dec 16 '15 at 19:26

score 1 · Accepted Answer · answered Dec 15 '15 at 19:48

No. You cannot execute the same async task twice. You are able to do it again after 30 secs because the async task completes processing and returns the result from doInBackground(). Hence you need to create an object every time or use a progress dialog to block the user from clicking on the button again. Show the progress dialog in onPreExecute() and dismiss in onPostExecute().

score 1 · Answer 2 · answered Dec 15 '15 at 20:32

You can use one instance of an asynctask object and reexecute it, I use this and work for me:

if(yourAsyncTaskInstance!=null &&
                yourAsyncTaskInstance.getStatus() == AsyncTask.Status.FINISHED){
            yourAsyncTaskInstance = new YourAsyncTaskClass();
            yourAsyncTaskInstance.execute();
}

score 0 · Answer 3 · answered Dec 15 '15 at 19:28

0

WIthout seeing your code, it's difficult to know why it might be working after a 30 second wait, but, you are correct: as the docs say, "The task can be executed only once (an exception will be thrown if a second execution is attempted.)"

answered Dec 15 '15 at 19:28

JatraTim

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AsyncTask and error when executed twice

3 Answers3