OnPostExecute run before doInBackground finish -AsyncTask

Question

In my Android project, I'm using AsyncTask for Facebook API news feed request. I'm getting error: OnPostExecute method executed before doInBackground request finish.

 private class NewsFeedAsyncTask extends AsyncTask < Integer, Integer, Boolean > {

     @Override
     protected Boolean doInBackground(Integer...params) {
        if (Session.getActiveSession().getState().isOpened()) {
            Get_news_feed();
            return true;
        }
        return false;
     }

     @Override
     protected void onPostExecute(Boolean t) {
         super.onPostExecute(t);
         adapter = new FacebookAdapter(data, context);
         listView.setAdapter(adapter);
         adapter.notifyDataSetChanged();
         mPullRefreshListView.onRefreshComplete();
     }
 }

fetchNewsFeed ()

public void fetchNewsFeed() {
    Session.openActiveSessionFromCache(context);
    if (Session.getActiveSession().getState().isOpened()) {
        Request.executeGraphPathRequestAsync(
            Session.getActiveSession(), "me/home", new Request.Callback() {
                @Override
                public void onCompleted(
                    Response response) {

                }
            }
        }
    }
}

OnActivityCreated()

 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
     super.onActivityCreated(savedInstanceState);
     new NewsFeedAsyncTask().execute();
 }

Answer 1

The onPostExecute method is always executed after doInBackground.

Your problem is that the Get_news_feed method (which is executed in background from the doInBackground method) posts some stuff to be done back on the UI thread with runOnUiThread and then returns (before the stuff posted on UI thread is executed).

If you expect the Get_news_feed to be synchronous (everything done before returning), you should not post anything on the UI thread.

Just do all the UI stuff in onPostExecute instead.