Ява — получить значение long long с сервера, но вместо этого получить нулевое значение. Получение ответа JSON равно нулю

Я получаю значения lat long с сервера, но когда я получаю JSON, он дает мне нулевое значение. это мой код, где он получает JSON

private void getJSON(String url) {
class GetJSON extends AsyncTask<String, Void, String>{
ProgressDialog loading;

@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(MapActivity.this, "Please Wait...",null,true,true);
}

@Override
protected String doInBackground(String... params) {

String uri = params[0];

BufferedReader bufferedReader = null;
try {
URL url = new URL(uri);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
StringBuilder sb = new StringBuilder();

bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));

String json;
while((json = bufferedReader.readLine())!= null){
sb.append(json+"\n");
}

return sb.toString().trim();

}catch(Exception e){
return null;
}

}

@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
q=s;
}
}
GetJSON gj = new GetJSON();
gj.execute(url);
}

Мой весь код:

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

GPSTracker gps = new GPSTracker(this);

curLat = gps.getLatitude();
curLng = gps.getLongitude();

try {
// Loading map
initilizeMap();

} catch (Exception e) {
e.printStackTrace();
}


}

private void extractJSON(){
try {
JSONObject jsonObject = new JSONObject(q);
users = jsonObject.getJSONArray(JSON_ARRAY);
} catch (JSONException e) {
e.printStackTrace();
}
}

private void showData() {
if(i <= users.length()) {
try {
JSONObject jsonObject = users.getJSONObject(i);

double maplat = Double.parseDouble((jsonObject.getString(lat)));
double maplng = Double.parseDouble((jsonObject.getString(lng)));

MarkerOptions marker = new MarkerOptions().position(new LatLng(maplat, maplng)).title("Hello Maps");

marker.icon(BitmapDescriptorFactory.fromResource(R.drawable.pin));

googleMap.addMarker(marker);

} catch (JSONException e) {
e.printStackTrace();
}
}
}

private void getJSON(String url) {
class GetJSON extends AsyncTask<String, Void, String>{
ProgressDialog loading;

@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(MapActivity.this, "Please Wait...",null,true,true);
}

@Override
protected String doInBackground(String... params) {

String uri = params[0];

BufferedReader bufferedReader = null;
try {
URL url = new URL(uri);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
StringBuilder sb = new StringBuilder();

bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));

String json;
while((json = bufferedReader.readLine())!= null){
sb.append(json+"\n");
}

return sb.toString().trim();

}catch(Exception e){
return null;
}

}

@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
q=s;
}
}
GetJSON gj = new GetJSON();
gj.execute(url);
}

private void initilizeMap() {
if (googleMap == null) {
googleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();

// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
}

MarkerOptions marker = new MarkerOptions().position(new LatLng(curLat, curLng)).title("Hello Maps");

// Changing marker icon
marker.icon(BitmapDescriptorFactory.fromResource(R.drawable.pin));

// adding marker
googleMap.addMarker(marker);

getJSON(GET_URL);
extractJSON();
showData();
}

@Override
protected void onResume() {
super.onResume();
initilizeMap();
}
}

PHP Код

<?php

require_once('dbConnect.php');

$sql = "SELECT * FROM eventinfo";

$res = mysqli_query($con,$sql);
$result = array();
while($row = mysqli_fetch_array($res)) {
array_push($result,
array('lat'=>$row[9],'lng'=>$row[10]));
}
echo json_encode(array("result"=>$result));
mysqli_close($con);

?>