Can't set spinner Adapter from AsyncThread
<p>I am fetching some data from php and trying to show that data in spinner through arrayadater, but there is a prob can   </p>

<pre><code>**DownloadDetails downloaddeatils = new DownloadDetails(this);
        downloaddeatils.execute(url);




    public class DownloadDetails extends AsyncTask&lt;String, Void, String&gt; {
        Context context;
        ProgressDialog progressDialog;
        public DownloadDetails(Context context) {
            this.context = context;
            progressDialog = new ProgressDialog(context);
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            progressDialog.setMessage("Fetching Data, please wait...");
            progressDialog.setCancelable(false);
            progressDialog.show();
        }

        @Override
        protected String doInBackground(String... urls) {
            String output = null;
            for(String url: urls) {
                output = getOutputFromUrl(url);
            }
            return output;
        }**
 private String getOutputFromUrl(String url) {
                try {
                    DefaultHttpClient httpClient = new DefaultHttpClient();
                    HttpPost httpPost = new HttpPost(url);
                    JSONObject object = null;
                    JSONObject object1 = null;
                    JSONObject object2 = null;
                    HttpPost httppost = new HttpPost(url);
                    List&lt;NameValuePair&gt; nameValuePairs = new ArrayList&lt;NameValuePair&gt;(5);
                    nameValuePairs.add(new BasicNameValuePair("speciality_id", sid));
                    nameValuePairs.add(new BasicNameValuePair("type",type)); 
                    nameValuePairs.add(new BasicNameValuePair("condition_id", cid));
                    nameValuePairs.add(new BasicNameValuePair("locality", locality));
                    nameValuePairs.add(new BasicNameValuePair("city_name", city_name));
                    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));       
                    ResponseHandler&lt;String&gt; responseHandler = new BasicResponseHandler();
                    String responseBody = httpClient.execute(httpPost,
                            responseHandler);
                    Log.d("Respone",responseBody);
                    if(!responseBody.equals(null))
                    {

                    JSONObject jsonResponse = new JSONObject(responseBody);
                    object = jsonResponse.getJSONObject("firstarray");
                    object1 = jsonResponse.getJSONObject("secondarray");
                    object2 = jsonResponse.getJSONObject("thirdarray");
                    try {

                        if (!object.toString().trim().contains("null")) {
                            Log.d("Inside ","count"+count);
                            if (count == 0) {
                                JSONArray jArray = object.getJSONArray("values");
                                for (int i = 0; i &lt; jArray.length(); i++) {
                                    String str = jArray.getString(i).substring(0,
                                            jArray.getString(i).length());
                                    String[] data = str.split("_");
                                    specialistList.add(data[0]);
                                    specialistNameList.add("" + data[1]);
                                    //specialistAdapter.add("" + data[1]);
                                }
                                //specialistAdapter.setNotifyOnChange(true);
                                count = 1;

                            }
                        }
                        if (!object1.toString().trim().contains("null")) {
                            JSONArray JArray1 = object1.getJSONArray("values1");
                            for (int i = 0; i &lt; JArray1.length(); i++) {
                                String str = JArray1.getString(i).substring(0,
                                        JArray1.getString(i).length());
                                String[] data = str.split("_");
                                conditionList.add(data[0]);
                                //conditionAdapter.add(data[1]);
                                conditionNameList.add(data[1]);
                            }
                            //conditionAdapter.setNotifyOnChange(true);
                            Log.d("Inside","SecondArray");
                        }
                        if (!object2.toString().trim().contains("null")) {
                            JSONArray JArray1 = object2.getJSONArray("values2");
                            for (int i = 0; i &lt; JArray1.length(); i++) {
                                String str = JArray1.getString(i).substring(0,
                                        JArray1.getString(i).length());
                                String[] data = str.split("_");
                                doctorIdList.add(data[0]);
                                doctorNameList.add(data[1]);
                            //  adapter.add(data[1]);
                            }
                        //  adapter.setNotifyOnChange(true);
                        }

                    } catch (Exception e) {
                        Log.d("Unknown exception",""+e);
                        e.printStackTrace();
                        } 
                    }
                    else
                    {
                        Toast.makeText(getApplicationContext(),"Unable to fetch data from server",Toast.LENGTH_LONG).show();
                    }
               }
                catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                } catch (ClientProtocolException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (JSONException e1) {
                    e1.printStackTrace();
                }
                return null;
            }

            @Override
            protected void onPostExecute(String output) {
                super.onPostExecute(output);
                if (progressDialog.isShowing()) {
                    progressDialog.dismiss();
                                    for(int i=0;i&lt;specialistNameList.size();i++)
                    specialistAdapter.add(specialistNameList.get(i));
                for(int j=0;j&lt;conditionNameList.size();j++)
                    conditionAdapter.add(conditionNameList.get(j));
                for(int k=0;k&lt;doctorNameList.size();k++)
                    adapter.add(doctorNameList.get(k));

                }

                if(output != null) {
                    Toast.makeText(getApplicationContext(), "Cannot connect to Server",Toast.LENGTH_LONG).show();
                }
                else {

                }        
        }
    }
</code></pre>
