AsyncTask return null when re-requested

There is a task to download data from api, process and transfer the list to mainActivity. The first time I load the data, everything works fine - when the second run, asyncTask constantly returns null. The stream is triggered (in the doinBackground it generates new data, but does not send it to the activation), how to fix it?

@Override public void onClick(View v) { try { switch (v.getId()){ case R.id.btnStartSearch: String query_str = etSearch.getText().toString(); if(!query_str.isEmpty()){ List<ContactItem> list = new ArrayList<>(); LoadAPI loadAPI = new LoadAPI(); loadAPI.execute(query_str); list = loadAPI.get(); if(list == null){ Toast.makeText(this, "Введіть коректніші дані пошуку!", Toast.LENGTH_SHORT).show(); } else { initRecycler(list); Log.println(Log.INFO, "api", "list size - " + list.size()); } //loadAPI.cancel(true); //loadAPI.execute("close", loadAPI.toString()); //loadAPI.execute(); } else { Toast.makeText(this, "Помилка! Введіть данні пошуку!", Toast.LENGTH_SHORT).show(); } break; } } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } } 

here's the stream code

 public class LoadAPI extends AsyncTask<String, Void, List<ContactItem>> { private List<ContactItem> contactItemList; @Override protected List<ContactItem> doInBackground(String... strings) { try { String query = URLEncoder.encode(strings[0], "UTF-8"); String link_query = "https://public-api.nazk.gov.ua/v1/declaration/? q=" + query; Log.println(Log.INFO, "api", link_query); Document document = Jsoup.connect(link_query).ignoreContentType(true).get(); String result = document.text(); //dell Log.println(Log.INFO, "api", result); JSONObject jsonObject = new JSONObject(result); JSONArray arrayTovars = jsonObject.getJSONArray("items"); int count = jsonObject.getJSONObject("page").getInt("totalItems"); if (count < 500) { contactItemList = new ArrayList<>(); Log.println(Log.INFO, "api", "count: " + count); for (int i = 0; i < arrayTovars.length(); i++) { ContactItem contact = new ContactItem(); JSONObject item = arrayTovars.getJSONObject(i); contact.setId(item.getString("id")); contact.setFirst_name(item.getString("firstname")); contact.setLast_name(item.getString("lastname")); contact.setMisce_rob(item.getString("placeOfWork")); contact.setPosada(item.getString("position")); contact.setLink_pdf(item.getString("linkPDF")); contact.setLink_pdf(item.getString("linkPDF")); contactItemList.add(contact); } } else { return null; } //String res = contactItemList.get(0).getLast_name() + " " + contactItemList.get(0).getFirst_name(); //Log.println(Log.INFO, "api", res); return contactItemList; } catch (IOException e) { e.printStackTrace(); } catch (JSONException e) { e.printStackTrace(); } return null; } @Override protected void onProgressUpdate(Void... values) { super.onProgressUpdate(values); } @Override protected void onPreExecute() { super.onPreExecute(); } @Override protected void onPostExecute(List<ContactItem> list) { super.onPostExecute(list); } } 

Thank you so much for the help in advance.