[android help] How do I return a global arraylist from an asynctask in android?

I am trying to fill a global ArrayList of JSONObjects in an AsycTask, but my app keeps crashing and giving me a null pointer exception. I am setting the arraylist = the ArrayList that the "doInBackground" returns to "onPostExecute", but it is not actually populating my arrayList.

Am I missing something?

  private class checkPlacesAround extends AsyncTask> {
         protected ArrayList doInBackground(LatLng... ll) {
             ArrayList ar = getPlacesArray(ll[0]);           
             return ar;
         }

     protected void onProgressUpdate(Integer... progress) {
     }

     protected void onPostExecute(ArrayList result) {
         placesJSONArray = result;
     }

     /**
         * give this a LatLng object and it will
         * get the return an ArrayList of JSONObjects
         * which includes that are the distances of 
         * all the places in the database from the 
         * LatLng point.
         * 
         * @param ll LatLng 
         * @return ArrayList
         */
        private ArrayList getPlacesArray(LatLng ll) {
            ArrayList jsonArray = new ArrayList();
            HttpURLConnection httpconn;
            Cursor c = getPlaces();
            c.moveToFirst();
            while(!c.isLast()){             
                String type = c.getString(0);
                String stringUrl = "https://maps.googleapis.com/maps/api/place/nearbysearch/" +
                        "json?location="+ ll.latitude +","+ ll.longitude +
                        "&radius=500&" +
                        type + "&" +
                        "sensor=false&" +
                        "key=" + apiKey;
                URL url;
                try {
                    url = new URL(stringUrl);               
                    StringBuilder response = new StringBuilder();
                    try {
                        httpconn = (HttpURLConnection)url.openConnection();          
                        if(httpconn.getResponseCode() == HttpURLConnection.HTTP_OK){                 
                            try {
                                BufferedReader input = new BufferedReader(new InputStreamReader(httpconn.getInputStream()));
                                String strLine = null;
                                while((strLine = input.readLine()) != null){
                                    response.append(strLine);
                                }
                                input.close();
                            }catch (IOException e) {
                                //  TODO Auto-generated catch block
                                e.printStackTrace();
                            }
                        }
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    try {
                        JSONObject json = new JSONObject(response.toString());                          
                        jsonArray.add(json);
                        Log.e("getting json", jsonArray.get(0).toString());
                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                } catch (MalformedURLException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
                c.moveToNext();
            }
            return jsonArray;
        }


        /**
         * returns a Cursor that contains the places
         * @return
         */
        private Cursor getPlaces(){
            SQLiteDatabase db = openOrCreateDatabase("MyDB", MODE_PRIVATE, null);
            try{
                Cursor c = db.rawQuery("SELECT name FROM placesToGoArray", null);
                c.moveToFirst();
                return c;
            }
            catch(android.database.sqlite.SQLiteException e){
                return null;
            }
        }
 }

here is my error from logcat

04-27 01:14:12.786: E/AndroidRuntime(25662): FATAL EXCEPTION: main
04-27 01:14:12.786: E/AndroidRuntime(25662): java.lang.NullPointerException
04-27 01:14:12.786: E/AndroidRuntime(25662):    at     winlab.findplaces2.JSONstuff$getJSONDirections.onPostExecute(JSONstuff.java:226)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at winlab.findplaces2.JSONstuff$getJSONDirections.onPostExecute(JSONstuff.java:1)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at   android.os.AsyncTask.finish(AsyncTask.java:631)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at android.os.AsyncTask.access$600(AsyncTask.java:177)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at  android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at android.os.Handler.dispatchMessage(Handler.java:99)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at android.os.Looper.loop(Looper.java:137)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at android.app.ActivityThread.main(ActivityThread.java:5039)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at java.lang.reflect.Method.invokeNative(Native Method)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at java.lang.reflect.Method.invoke(Method.java:511)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-27 01:14:12.786: E/AndroidRuntime(25662):    at dalvik.system.NativeStart.main(Native Method)

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