I'm developing a JSON Parsing app in Android, I have a php script on my server to fetch all data from mysql database and encode to json, the app contact to the server and populate the ListView with the data from JSON using AsyncTaskLoader . It's worked but if I drop all database records, then start my app again, the ListView still shows old data. Even I press the refresh button that call AsyncTaskLoader but still old data. I don't know why please help me.
Thank you P/s: Sorry for my bad English ^^
Sorry, I forgot the code. Here we go
TVSchedFragment.java
public class TVSchedFragment extends ListFragment {
private TVSchedAdapter adpt;
ListView lView;
// JSON Node names
private static final String TAG_SCHEDULE = "Sched";
private static String url = "http://192.168.20.205/DOM/app/json.php";
String jsonStr;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_tvsched, container,
false);
lView = (ListView) rootView.findViewById(android.R.id.list);
adpt = new TVSchedAdapter(new ArrayList<TVSchedModel>(), getActivity());
lView.setAdapter(adpt);
(new AsyncListViewLoader()).execute();
return rootView;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_tvsched, menu);
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_tvsched_refresh:
(new AsyncListViewLoader()).execute();
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
private class AsyncListViewLoader extends
AsyncTask<String, Void, List<TVSchedModel>> {
private final ProgressDialog dialog = new ProgressDialog(getActivity());
@Override
protected void onPostExecute(List<TVSchedModel> result) {
super.onPostExecute(result);
dialog.dismiss();
adpt.setItemList(result);
adpt.notifyDataSetChanged();
}
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog.setMessage("Downloading schedule...");
dialog.show();
}
@Override
protected List<TVSchedModel> doInBackground(String... params) {
List<TVSchedModel> result = new ArrayList<TVSchedModel>();
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
JSONArray contacts = jsonObj.getJSONArray(TAG_SCHEDULE);
for (int i = 0; i < contacts.length(); i++) {
result.add(convertSched(contacts.getJSONObject(i)));
}
return result;
} catch (Throwable t) {
t.printStackTrace();
}
return null;
}
private TVSchedModel convertSched(JSONObject obj)
throws JSONException {
String name = obj.getString("Program");
String desc = obj.getString("Description");
String time = obj.getString("dateTimeString");
String chan = obj.getString("Channel");
return new TVSchedModel(time, name, desc, chan);
}
}
@Override
public void onDestroy() {
super.onDestroy();
adpt.clear();
}
}
ServiceHandler.java
public class ServiceHandler {
static String response = null;
public final static int GET = 1;
public final static int POST = 2;
public ServiceHandler() {
}
/*
* Making service call
* @url - url to make request
* @method - http request method
* */
public String makeServiceCall(String url, int method) {
return this.makeServiceCall(url, method, null);
}
/*
* Making service call
* @url - url to make request
* @method - http request method
* @params - http request params
* */
public String makeServiceCall(String url, int method,
List<NameValuePair> params) {
try {
// http client
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpEntity httpEntity = null;
HttpResponse httpResponse = null;
// Checking http request method type
if (method == POST) {
HttpPost httpPost = new HttpPost(url);
// adding post params
if (params != null) {
httpPost.setEntity(new UrlEncodedFormEntity(params));
}
httpResponse = httpClient.execute(httpPost);
} else if (method == GET) {
// appending params to url
if (params != null) {
String paramString = URLEncodedUtils
.format(params, "utf-8");
url += "?" + paramString;
}
HttpGet httpGet = new HttpGet(url);
httpResponse = httpClient.execute(httpGet);
}
httpEntity = httpResponse.getEntity();
response = EntityUtils.toString(httpEntity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return response;
}
}
