Android background task

Question

I need to start background task. Task call async http request and if condition is valid show alert.

I implemented it but I receive this error:

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

This is my java code:

    Timer timer = new Timer();
    timer.schedule(new RequestScheduledTask(), intervalTask);

    class RequestScheduledTask extends TimerTask {
    @Override
    public void run() {
            myCall();
    }
}

Can you help me please?

Thanks

Luca

did an update on my answer – Langusten Gustel Oct 23 '13 at 11:14 — Langusten Gustel, Oct 23 '13 at 11:14

score 0 · Answer 1 · edited May 23 '17 at 10:25

According to the following post you are doing something in a thread that is meant to be called on the main thread! What is myCall(); doing?

Can't create handler inside thread that has not called Looper.prepare()

And don't do http request with async tasks thats bad practice.

I would recomment to use volley:

http://www.itsalif.info/content/android-volley-tutorial-http-get-post-put

[edit]

Okay its the loading indicator that is should be called on the main thread. I guess you are doing it in the AsyncTask. You can use Activity.runOnUiThread(Runnable()) to run a runnable to display it.

score 0 · Answer 2 · answered Oct 23 '13 at 08:35

for example I need refresh adapter list when data is changed. Data returned from webserver could to be changed or not. if it is changed I must refresh listview/adapter, else nothing.

myCall call server, get data response (using other framwork like volley) and then update list view.

When myCall start I want display loading indicator but when I show it, app crash with runtime exception

  java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Android background task

2 Answers2