Null Data from onResponse() of volley in Fragment' onCreateView()

Question

I am trying to get some country data from a URL using volley. In onResponse() data is successfully added to countryList and countryList.size() shows it has 5 countries. But in onCreateView(), when I try to use countryList, it is null and throws NullPointerException because of countryList.size() as countryList has null value. Thanks in advance, here's the code:

public class MyAddress extends Fragment {


    ArrayList<Countries> countryList;


    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.shipping_address, container, false);

        RequestCountries();

        Toast.makeText(getContext(), countryList.size(), Toast.LENGTH_SHORT).show();
        //Some code to use countryList

        return rootView;
    }



    private void RequestCountries() {


        final String urlLink = ConstantValues.BASE_URL + "getCountries";

        StringRequest countryRequest = new StringRequest
            (
                    Request.Method.GET,
                    urlLink,

                    new Response.Listener<String>() {

                        @Override
                        public void onResponse(String response) {

                            JSONObject jsonResponse = new JSONObject(response);
                            JSONArray countries = jsonResponse.getJSONArray("countries");

                            for (int i=0;  i< countries.length();  i++) {

                                JSONObject countryInfo = countries.getJSONObject(i);

                                String country_id = countryInfo.getString("country_id");
                                String country_name = countryInfo.getString("country_name");


                                Countries country = new Countries();
                                country.setCountry_id(country_id);
                                country.setCountry_name(country_name);

                                countryList.add(country);
                            }
                        }
                    },

                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            error.printStackTrace();
                            Toast.makeText(getContext(), error.toString(), Toast.LENGTH_SHORT).show();
                        }
                    }
            );

        RequestQueue requestQueue = Volley.newRequestQueue(getContext());
        requestQueue.add(countryRequest);

    }
}

useless links, i know the case, but how to resolve this – Hawk437 Aug 26 '16 at 05:34 — Hawk437, Aug 26 '16 at 05:34

score 1 · Answer 1 · answered Aug 25 '16 at 14:51

1

You have not initialized ArrayList<Countries> countryList. Try initializing the ArrayList in your onCreateView before you call RequestCountries() method as

countryList = new ArrayList<>();

answered Aug 25 '16 at 14:51

Navjacinth Mathew

525
1
4
12

tried, doesn't work – Hawk437 Aug 26 '16 at 05:31

score 0 · Answer 2 · answered Aug 25 '16 at 17:07

0

Do you know Volley execute Asynchronously means method after volley code can may execute it dose not wait for execute volley code and response is recive.in Your case it happen,your toast es executed before volley code complete execution .so u need to put your all code after the method RequestCountries() inside ur volley response method.try this

answered Aug 25 '16 at 17:07

vikash kumar tiwari

29
4

yeah i know that might be the case, but how to resolve it? – Hawk437 Aug 26 '16 at 05:32
it will be a bad idea to put all other stuff into volley response – Hawk437 Aug 26 '16 at 05:33

Null Data from onResponse() of volley in Fragment' onCreateView()

2 Answers2