public class Config {
       public static final String DATA_URL = "http://192.168.33.203/obs/json.php";

        public static final String TAG_USERNAME = "username";
        public static final String TAG_NAME = "name";
        public static final String TAG_PASSWORD= "password";
        public static final String TAG_ID = "id";

        //JSON array name
        public static final String JSON_ARRAY = "result";
    }


 private void getData(){
        StringRequest stringRequest = new StringRequest(Config.DATA_URL,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        JSONObject j = null;
                        try {

                            j = new JSONObject(response);

                            result = j.getJSONArray(Config.JSON_ARRAY);

                            getUser(result);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {

                    }
                });
        RequestQueue requestQueue = Volley.newRequestQueue(this);

        requestQueue.add(stringRequest);
    }