How to edit SharedPreferences without blocking UI Thread? - android-asynctask

Question

I want to put many values in SharedPreferences but doing so is blocking my UI thread. I tried to do it in ASyncTask's doInBackground() and also by using a Handler, but both attempts turned out to be of no use.
Here's the method:
....
Context c = RamadanWidgetConfig.this;
savedDataSehri = c.getSharedPreferences("Sehri", 0);
savedDataIftar = c.getSharedPreferences("Iftar", 0);
boolean sFilled = savedDataSehri.getBoolean("filled", false);
boolean iFilled = savedDataIftar.getBoolean("filled", false);
if (!sFilled || !iFilled) {
fillSharedPreferences();
} ....
private void fillSharedPreferences() {
String date[] = {"6/18/2015", "6/19/2015", "6/20/2015", "6/21/2015", "6/22/2015", "6/23/2015", "6/24/2015", "6/25/2015", "6/26/2015", "6/27/2015", "6/28/2015", "6/29/2015", "6/30/2015", "7/1/2015", "7/2/2015", "7/3/2015", "7/4/2015", "7/5/2015", "7/6/2015", "7/7/2015", "7/8/2015", "7/9/2015", "7/10/2015", "7/11/2015", "7/12/2015", "7/13/2015", "7/14/2015", "7/15/2015", "7/16/2015", "7/17/2015"};
String sehri[] = {"4:13 AM", "4:13 AM", "4:14 AM", "4:14 AM", "4:14 AM", "4:14 AM", "4:15 AM", "4:15 AM", "4:15 AM", "4:15 AM", "4:16 AM", "4:16 AM", "4:17 AM", "4:17 AM", "4:17 AM", "4:18 AM", "4:18 AM", "4:19 AM", "4:19 AM", "4:20 AM", "4:20 AM", "4:21 AM", "4:21 AM", "4:22 AM", "4:22 AM", "4:23 AM", "4:24 AM", "4:24 AM", "4:25 AM", "4:26 AM"};
String iftar[] = {"7:24 PM", "7:25 PM", "7:25 PM", "7:25 PM", "7:25 PM", "7:25 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:26 PM", "7:25 PM", "7:25 PM", "7:25 PM", "7:25 PM", "7:24 PM"};
SharedPreferences.Editor editorSehri = savedDataSehri.edit();
SharedPreferences.Editor editorIftar = savedDataIftar.edit();
for (int i = 0; i < date.length; i++) {
editorSehri.putString(date[i], sehri[i]);
editorIftar.putString(date[i], iftar[i]);
}
editorSehri.putBoolean("filled", true);
editorIftar.putBoolean("filled", true);
editorSehri.apply();
editorIftar.apply();
}
Basically, I am adding a widget to home screen and before adding it I am checking if I have the data or not. This method gets called if I don't have the data. If this does not get called then the other code executes within milliseconds.
EDIT: Actually I found out that problem lies somewhere else. I was clearing data of app before adding the widget to clear SharedPreferences, but I later found out that clearing data also clears something else which is related to the first launch of the app. The app always takes long while launching for the first time. Perhaps it is setting things up, but I don't exactly know what's going on. So after clearing the data and then adding the widget, the app essentially launched for the first time. This is why it was slowing down and I thought that SharedPreferences was making it slow.
Now I need to figure out why the app takes so long in its first launch and how to avoid it. (Splash screen comes first to my mind).

Answer 1

Not clear what part is responsible for populating data. Generally SharedPreferences is thread safe, but doesn't support use across multiple processes.
With a cold start (no data) how do you wait result? Constant checking still can block UI, even if you use threading to insert data.
If you use a huge amount of structured data set consider to use SQLite.
To populate data you may use service.