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POHow to stop the AsyncTask if the result of fetching data is null?
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copied!<p>I want to cancel the asyncTask if my result string is null. ( I get a username and password from the user in a login activity and if this username and password don't exist in the database, the asyncTask has to cancel and ready to start the same task.) I read and applied something but they didn't run. Here is my AsyncTask :</p> <pre><code>class ProductConnect extends AsyncTask<Boolean, String, String> { public AsyncResponse delegate=null; private Activity activity; public void MyAsyncTask(Activity activity) { this.activity = activity; } @Override protected String doInBackground(Boolean... params) { String result = null; StringBuilder sb = new StringBuilder(); try { // http post HttpClient httpclient = new DefaultHttpClient(); HttpGet httppost = new HttpGet( "http://191.165.2.235/getProducts.php?login=1&user_name="+UserName+"&user_pass="+Password); HttpResponse response = httpclient.execute(httppost); if (response.getStatusLine().getStatusCode() != 200) { Log.d("MyApp", "Server encountered an error"); } BufferedReader reader = new BufferedReader( new InputStreamReader( response.getEntity().getContent(), "UTF8")); sb = new StringBuilder(); sb.append(reader.readLine() + "\n"); if(reader.readLine() == null){ asyncTask.cancel(true); } String line = null; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); if (isCancelled()) break; } result = sb.toString(); Log.d("test", result); } catch (Exception e) { Log.e("log_tag", "Error converting result " + e.toString()); } return result; } @Override protected void onPostExecute(String result) { Intent passValue=new Intent(MainActivity.this, second.class); try { JSONArray jArray = new JSONArray(result); JSONObject json_data; for (int i = 0; i < jArray.length(); i++) { json_data = jArray.getJSONObject(i); t = json_data.getString("name"); names.add(t); latitude=json_data.getString("lat"); lats.add(latitude); longtitude=json_data.getString("lon"); longts.add(longtitude); } passValue.putStringArrayListExtra("latitudes", (ArrayList<String>) lats); passValue.putStringArrayListExtra("veri", (ArrayList<String>) names); passValue.putStringArrayListExtra("longtitudes", (ArrayList<String>) longts); startActivity(passValue); } catch (JSONException e1) { e1.printStackTrace(); } catch (ParseException e1) { e1.printStackTrace(); } super.onPostExecute(result); } protected void onPreExecute() { super.onPreExecute(); ProgressDialog pd = new ProgressDialog(MainActivity.this); pd.setTitle("Lütfen Bekleyiniz"); pd.setMessage("Authenticating.."); pd.show(); } } </code></pre> <p>How should i follow a way ? Which methods should i use? </p>

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