private class DownloadJSONItems extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // Create a progressbar
        if (!prefs) {
            progressBar.setVisibility(View.VISIBLE);
        }
    }

    @Override
    protected Void doInBackground(Void... params) {
        // Create an array
        arraylist = new ArrayList<HashMap<String, String>>();
        // Retrieve JSON Objects from the given URL address
        jsonobject = JSONfunctions
                .getJSONfromURL(
                        "Server URL",
                        latitude, longitude);

        try {
            // Locate the array name in JSON
            jsonarray = jsonobject.getJSONArray("places");

            for (int i = 0; i < jsonarray.length(); i++) {
                HashMap<String, String> map = new HashMap<String, String>();
                jsonobject = jsonarray.getJSONObject(i);

                double convertString = Double.parseDouble(jsonobject
                        .getString("distance"));
                double convertKMToMile = convertString * 0.6124;
                String convertedValue = String.format("%.2f",
                        convertKMToMile);
                // Retrive JSON Objects
                map.put("places_name", jsonobject.getString("places_name"));
                map.put("distance", convertedValue);
                map.put("places_icon", jsonobject.getString("places_icon"));
                // Set the JSON Objects into the array
                arraylist.add(map);
            }
        } catch (JSONException e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void args) {

        //Toast.makeText(getActivity(), getString(jsonarray.length()), 6000).show();
        // Pass the results into ListViewAdapter.java
        adapter = new ListViewAdapter(getActivity(), arraylist);
        // Set the adapter to the ListView
        listview.setAdapter(adapter);
        // Close the progressbar
        progressBar.setVisibility(View.GONE);
        if (prefs) {
            prefs = false;
        }
    }
}