Android สอบถามเรื่องการดึงข้อมูลมาทำ Marker จาก MySQL มาแสดงบน Google map ใน Fragment หน่อยค่ะ

public class Fragmentmap extends Fragment implements OnMapReadyCallback  {
GoogleMap mGoogleMap;
MapView mMapView;
View mView;
ArrayList<String> machinid;
ArrayList<Double> latitude;
ArrayList<Double> longitude;
int unit;
public Fragmentmap() {
    // Required empty public constructor
}
@Override
public void onCreate( Bundle savedInstanceState) {super.onCreate(savedInstanceState);   }
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {                                
    mView= inflater.inflate(R.layout.fragment_fragmentmap, container, false);            
    machinid= new ArrayList<String>();
    latitude=new ArrayList<Double>();
    longitude=new ArrayList<Double>();
    // Inflate the layout for this fragment
    new AsyncTask<Void, Void, Void>() {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }
        @Override
        protected Void doInBackground(Void... params) {
            try {
                URL url = new URL("http://192.168.0.87/fragment2getlocal.php");
                URLConnection urlConnnection=url.openConnection();
                HttpURLConnection httpURLConnection=(HttpURLConnection)urlConnnection;
                httpURLConnection.setAllowUserInteraction(false);
                httpURLConnection.setInstanceFollowRedirects(true);
                httpURLConnection.setRequestMethod("GET"); 
                httpURLConnection.connect();
                InputStream inputStream = null;
                if(httpURLConnection.getResponseCode()==HttpURLConnection.HTTP_OK)
                {
                    inputStream=httpURLConnection.getInputStream();
                }
                BufferedReader reader= new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"),8);
                //ส่งค่าที่อ่านไป String Viewder
                StringBuilder stringBuilder=new StringBuilder();
                String line=null;
                while ((line=reader.readLine()) != null)
                {
                    stringBuilder.append(line+"\n");
                }
                inputStream.close();
                Log.d("JSON Result",stringBuilder.toString());

                JSONObject jsonObject=new JSONObject(stringBuilder.toString());
                JSONArray exArray=jsonObject.getJSONArray("result");
                unit=exArray.length();
                for (int i=0;i<exArray.length();i++)
                {
                    JSONObject jsonObj =exArray.getJSONObject(i);
                    machinid.add(jsonObj.getString("machinid"));
                    latitude.add(jsonObj.getDouble("latitude"));
                    longitude.add(jsonObj.getDouble("longitude"));
                }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return null;
        }
        @Override
        protected void onProgressUpdate(Void... values) {
            super.onProgressUpdate(values);
        }
        @Override
        protected void onPostExecute(Void aVoid) {            }
    }.execute();
    return mView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    mMapView=(MapView)mView.findViewById(R.id.map);
    if (mMapView != null)
    {
        mMapView.onCreate(null);
        mMapView.onResume();
        mMapView.getMapAsync(this);
    }


@Override
public void onMapReady(GoogleMap googleMap) {        
    mGoogleMap=googleMap;
    mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(latitude.get(0),longitude.get(0)),18));
    mGoogleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
    for(int i=0;i<machinid.size();i++){
        MarkerOptions marker=new MarkerOptions().position(new LatLng(latitude.get(0),longitude.get(0))).title("New");
        mGoogleMap.addMarker(marker);
    }
}
}