Code:

public class MapsActivity3 extends FragmentActivity { GoogleMap map; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_maps3); setUpMapIfNeeded(); new MarkerTask().execute(); } private void setUpMapIfNeeded() { if (map != null) { MapFragment mapFragment = (MapFragment) getFragmentManager() .findFragmentById(R.id.map); map = mapFragment.getMap(); } } 52! private class MarkerTask extends AsyncTask<Void, Void, String> { private static final String LOG_TAG = "ExampleApp"; private static final String SERVICE_URL = "http://wewdemo.esy.es/create_product.php"; HttpURLConnection conn = null; BufferedReader reader = null; String resultJson = ""; @Override protected String doInBackground(Void... params) { try { URL url = new URL(SERVICE_URL); conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.connect(); InputStream inputStream = conn.getInputStream(); StringBuffer buffer = new StringBuffer(); reader = new BufferedReader(new InputStreamReader(inputStream)); String line; while ((line = reader.readLine()) != null) { buffer.append(line); } resultJson = buffer.toString(); } catch (Exception e) { e.printStackTrace(); } return resultJson; } @Override protected void onPostExecute(String strJson) { // Log.d(LOG_TAG, strJson); try { JSONObject obj = new JSONObject(strJson); JSONArray arr = obj.getJSONArray("markers"); for (int i = 0; i<arr.length(); i++) { JSONObject item = arr.getJSONObject(i); // String lng = item.getString("lng"); // String lat = item.getString("lat"); // Log.d(LOG_TAG, lng); // Log.d(LOG_TAG, lat); LatLng latLng = new LatLng(item.getDouble("lng"),item.getDouble("lat")); Log.d(LOG_TAG, String.valueOf(latLng)); 102! map.addMarker(new MarkerOptions().icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)).position(latLng)); } }catch (JSONException e) { e.printStackTrace(); } } } }

log-marked on which lines swears

 java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.maps.model.Marker com.google.android.gms.maps.GoogleMap.addMarker(com.google.android.gms.maps.model.MarkerOptions)' on a null object reference at com.example.admin.myapplication.MapsActivity3$MarkerTask.onPostExecute(MapsActivity3.java:102) at com.example.admin.myapplication.MapsActivity3$MarkerTask.onPostExecute(MapsActivity3.java:52)

Do not kick hard, novice =)))

    1 answer 1

    Working code: If I need someone, I can pour it on github

     public class MapsActivity3 extends FragmentActivity { SupportMapFragment mapFragment; GoogleMap map; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_maps3); new MarkerTask().execute(); mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); map = mapFragment.getMap(); if (map == null) { finish(); return; } } private class MarkerTask extends AsyncTask<Void, Void, String> { private static final String LOG_TAG = "ExampleApp"; private static final String SERVICE_URL = "http://wewdemo.esy.es/create_product.php"; HttpURLConnection conn = null; BufferedReader reader = null; String resultJson = ""; @Override protected String doInBackground(Void... params) { try { URL url = new URL(SERVICE_URL); conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.connect(); InputStream inputStream = conn.getInputStream(); StringBuffer buffer = new StringBuffer(); reader = new BufferedReader(new InputStreamReader(inputStream)); String line; while ((line = reader.readLine()) != null) { buffer.append(line); } resultJson = buffer.toString(); } catch (Exception e) { e.printStackTrace(); } return resultJson; } @Override protected void onPostExecute(String strJson) { // Log.d(LOG_TAG, strJson); try { JSONObject oblect = new JSONObject(strJson); JSONArray jsonArray =oblect.getJSONArray("markers"); for (int i = 0; i<jsonArray.length(); i++) { JSONObject item = jsonArray.getJSONObject(i); String lng = item.getString("lng"); String lat = item.getString("lat"); double latitude = Double.parseDouble(lat); double longitude = Double.parseDouble(lng); LatLng latLng = new LatLng(latitude, longitude); Log.d(LOG_TAG, String.valueOf(latLng)); map.addMarker(new MarkerOptions().position(latLng).icon( BitmapDescriptorFactory .defaultMarker(BitmapDescriptorFactory.HUE_GREEN))); } }catch (JSONException e) { Log.e(LOG_TAG,"Error"); } } } }