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List view in fragment with Async Task

my error log
I tried to load list view in my fragment.But my app crashes on clicking the button to populate my listview. I don't know what error i did.Any help will be appreciated.I have tried most of the stuffs regarding this..But nothing works well.(i have removed some codes to avoid clumsy look)
Here is my Fragment code :
public class Func extends Fragment {
ArrayList<Flowers> flowersList = new ArrayList<Flowers>();
String url ="http://113.193.30.155/MobileService/MobileService.asmx/GetSampleData";
#Override
public android.view.View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.tab2, container, false);
FlowerAdapter adapter=new FlowerAdapter(getActivity().getApplicationContext(),R.layout.flower_list_xml,flowersList);
ListView listView=(ListView)rootView.findViewById(R.id.listView);
listView.setAdapter(adapter);
return rootView;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
Button b = (Button)getView().findViewById(R.id.button);
b.setOnClickListener( new View.OnClickListener() {
#Override
public void onClick(View view) {
new BackTask().execute(url);
}
});
}
// My Async task starts here
public class BackTask extends AsyncTask<String, Void, String> {
#Override
protected void onPreExecute(){
super.onPreExecute();
}
#Override
protected String doInBackground(String... strings) {
String result = null;
BufferedReader reader = null;
try {
URL url = new URL(strings[0]);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
StringBuilder sb = new StringBuilder();
reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
Log.d("testhtt2", "test");
String line;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
Log.d("test44", sb.toString());
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
return result;
}
}
#Override
protected void onPostExecute(String s){
try {
JSONArray ar =new JSONArray(s);
for (int i = 0; i < ar.length(); i++){
JSONObject jsonObject=ar.getJSONObject(i);
Flowers flowers= new Flowers();
flowers.setName(jsonObject.getString("NAME"));
flowersList.add(flowers);
}
} catch (JSONException e) {
e.printStackTrace();
}

You return null in your doInBackground, which you then attempt to parse as a JSONArray in your OnPostExecute. Return a proper String from your doInBackground method, and see if that helps.

Do a null check before using getView() like
if(getView()!=null){
//Your code
}
Also it is better to initialize the button in oncreate view using the rootview intead of getview()
EDIT:
Your network call which your are doing has to be moved to doInBackground as it should be done in background thread and fetch the result.The fetched result should be added to the list in onPostExecute.Hope this helps you
public class SampleClass extends AsyncTask<String, Void, String> {
#Override
protected void onPreExecute(){
super.onPreExecute();
}
#Override
protected String doInBackground(String... strings) {
BufferedReader reader = null;
String result=null;
try {
URL url = new URL(strings[0]);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
StringBuilder sb = new StringBuilder();
reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
Log.d("testhtt2", "test");
String line;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
Log.d("test44", sb.toString());
result= sb.toString();
} catch (Exception e) {
e.printStackTrace();
result= null;
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
result= null;
}
}
return result;
}
}
#Override
protected void onPostExecute(String s){
try {
JSONArray ar =new JSONArray(s);
for (int i = 0; i < ar.length(); i++){
JSONObject jsonObject=ar.getJSONObject(i);
Flowers flowers= new Flowers();
flowers.setName(jsonObject.getString("NAME"));
flowersList.add(flowers);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}

you can try with view insteadof getView() in onViewCreated() method.
public class ListView extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.tab2, container, false);
return rootView;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Button b = (Button) view.findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
new BackTask().execute("http://113.193.30.155/MobileService/MobileService.asmx/GetSampleData");
}
});
}
private class BackTask extends AsyncTask<String, Void, String> {
String result;
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected String doInBackground(String... params) {
try {
result = Utility.executeHttpGet(params[0]);
} catch (Exception e) {
Log.e("ListView", e.getMessage(), e);
}
return result;
}
#Override
protected void onPostExecute(String s) {
try {
JSONArray ar = new JSONArray(s);
for (int i = 0; i < ar.length(); i++) {
JSONObject jsonObject = ar.getJSONObject(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}

Try this code
public class Listview extends Fragment {
ArrayList<Flowers> flowersList = new ArrayList<Flowers>();
String url ="http://113.193.30.155/MobileService/MobileService.asmx/GetSampleData";
ListView listview;
View rootView;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (rootView!= null) {
ViewGroup parent = (ViewGroup) view.getParent();
if (parent != null)
parent.removeView(view);
}
try {
rootView = inflater.inflate(R.layout.tab2, container, false);
} catch (InflateException ignored) {
}
listView=(ListView)rootView.findViewById(R.id.listView);
Button b = (Button)rootView.findViewById(R.id.button);
b.setOnClickListener( new View.OnClickListener() {
#Override
public void onClick(View view) {
new BackTask().execute(url);
}
});
return view;
}
private class BackTask extends AsyncTask<String,String,String>{
#Override
protected void onPreExecute(){
super.onPreExecute();
}
#Override
protected String doInBackground(String... strings) {
return null;
}
#Override
protected void onPostExecute(String s){
try {
JSONArray ar =new JSONArray(s);
for (int i = 0; i < ar.length(); i++){
JSONObject jsonObject=ar.getJSONObject(i);
Flowers flowers= new Flowers();
flowers.setName(jsonObject.getString("NAME"));
flowersList.add(flowers);
}
FlowerAdapter adapter=new FlowerAdapter(getActivity(),R.layout.flower_list_xml,flowersList);
listView.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}
}

Some Issue on sending data to next activity using onClickListner

i am trying to send Data (ID value) from one activity to other
but it wouldn't send correct data , i want it to send only ID Value of Clicked Item to next activity , here is my code
public class Order extends AppCompatActivity {
private ListView lvUsers;
private ProgressDialog dialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sub);
dialog = new ProgressDialog(this);
dialog.setIndeterminate(true);
dialog.setCancelable(false);
dialog.setMessage("Loading, please wait.....");
lvUsers = (ListView) findViewById(R.id.lvUsers);
new JSONTask().execute("http://146.185.178.83/resttest/order");
}
public class JSONTask extends AsyncTask<String, String, List<OrderModel> > {
#Override
protected void onPreExecute(){
super.onPreExecute();
dialog.show();
}
#Override
protected List<OrderModel> doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line ="";
while ((line=reader.readLine()) !=null){
buffer.append(line);
}
String finalJson = buffer.toString();
JSONArray parentArray = new JSONArray(finalJson);
List<OrderModel> orderModelList = new ArrayList<>();
Gson gson = new Gson();
for (int i = 0; i < parentArray.length(); i++) {
JSONObject finalObject = parentArray.getJSONObject(i);
OrderModel orderModel = gson.fromJson(finalObject.toString(), OrderModel.class);
orderModelList.add(orderModel);
}
return orderModelList;
}catch (MalformedURLException e) {
e.printStackTrace();
}catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if(connection !=null) {
connection.disconnect();
}
try {
if (reader !=null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(List<OrderModel> result) {
super.onPostExecute(result);
dialog.dismiss();
OrderAdapter adapter = new OrderAdapter(getApplicationContext(), R.layout.row_order, result);
lvUsers.setAdapter(adapter);
}
}
public class OrderAdapter extends ArrayAdapter {
public List<OrderModel> orderModelList;
private int resource;
private LayoutInflater inflater;
public OrderAdapter(Context context, int resource, List<OrderModel> objects) {
super(context, resource, objects);
orderModelList = objects;
this.resource = resource;
inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if(convertView == null){
holder = new ViewHolder();
convertView=inflater.inflate(resource, null);
holder.bOrderNo = (Button) convertView.findViewById(R.id.bOrderNo);
convertView.setTag(holder);
}else {
holder = (ViewHolder) convertView.getTag();
}
final int orderId = orderModelList.get(position).getId();
holder.bOrderNo.setText("Order No: " + orderModelList.get(position).getOrderId());
holder.bOrderNo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(Order.this, OrderSelected.class);
intent.putExtra("parameter_name", orderId);
startActivity(intent);
}
});
return convertView;
}
class ViewHolder{
private Button bOrderNo;
}
}
}
The holder gets executed in loop i guess is why it wouldn't send right Id.
How do i get it to send only Id of the clicked orderId
you can check this link to see how json Response looks like http://146.185.178.83/resttest/order

You have a silly mistake in your code . I have edited single line in your code . I think you are getting same "orderId" every time instead of actual "orderId". Check this one . I hope your problem will resolve .
final int index = position;
holder.bOrderNo.setText("Order No: " + orderModelList.get(position).getOrderId());
holder.bOrderNo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(Order.this, OrderSelected.class);
intent.putExtra("parameter_name", orderModelList.get(index).getId());
startActivity(intent);
}
});

Please try
In place of
intent.putExtra("parameter_name", orderId);
Please put
intent.putExtra("parameter_name", orderModelList.get(position).getId());

Can't get custom list adapter to populate listview using asynctask

I'm trying to populate an ArrayList of objects and use those objects to populate a ListView. My Asynctask can get the json data and I can parse it and make the objects I need but my ListView doesn't populate. When I check to see if my ArrayList has any object in it before the adapter runs I can see that it doesn't. I want to know why my ListView isn't populating.
Here's my code: (Sorry if it's messy, some spots I haven't gotten to updating yet)
public class MovieDisplayFragment extends Fragment{
private ArrayList<Movie> movieList = new ArrayList<Movie>();
private MovieAdapter movieAdapter;
ListView listView;
public MovieDisplayFragment(){
}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
movieAdapter = new MovieAdapter(getActivity(), movieList);
listView = (ListView) rootView.findViewById(R.id.listview_data);
listView.setAdapter(movieAdapter);
if(movieList.size() > 0) {
Log.e("Hello", "1");
}
listView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l){
Movie movie = movieAdapter.getItem(position);
Intent i = new Intent(getActivity(), DetailActivity.class)
.putExtra(Intent.EXTRA_TEXT, "Hello");
startActivity(i);
}
});
return rootView;
}
private void updateMovieData(){
getMovieData movieData = new getMovieData();
movieData.execute();
}
#Override
public void onStart(){
super.onStart();
updateMovieData();
}
public class getMovieData extends AsyncTask<Void, Void, List<Movie>> {
private final String LOG_CAT = getMovieData.class.getSimpleName();
private List<Movie> getMovieData(String movieJsonStr) throws JSONException {
final String MOV_ITEMS = "results";
final String MOV_TITLE = "original_title";
final String MOV_DATE = "release_date";
final String MOV_SYNOPSIS = "overview";
final String MOV_VOTE = "vote_average";
final String MOV_POSTER_URL = "poster_path";
JSONObject movieJson = new JSONObject(movieJsonStr);
JSONArray movieArray = movieJson.getJSONArray(MOV_ITEMS);
Log.e("Hello", "2");
for (int i = 0; i < movieArray.length(); i++) {
JSONObject movie = movieArray.getJSONObject(i);
movieList.add(new Movie(movie.getString(MOV_TITLE), movie.getString(MOV_DATE),
movie.getString(MOV_SYNOPSIS), movie.getString(MOV_VOTE), movie.getString(MOV_POSTER_URL)));
}
return movieList;
}
protected List<Movie> doInBackground(Void... params) {
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String movieJsonStr = null;
try {
final String BASE_URL = "http://api.themoviedb.org/3/genre/10751/movies?api_key=358f3b44734f7e6404f2d01a62d3c176&include_all_movies=true&include_adult=true";
Uri builtUri = Uri.parse(BASE_URL).buildUpon().build();
URL url = new URL(builtUri.toString());
Log.v(LOG_CAT, "Built URI " + builtUri.toString());
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null){
movieJsonStr = null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while((line = reader.readLine()) != null){
buffer.append(line + "\n");
}
if (buffer.length() == 0){
movieJsonStr = buffer.toString();
}
movieJsonStr = buffer.toString();
Log.v(LOG_CAT, "Movie String: " + movieJsonStr);
} catch (IOException e) {
Log.e("Fragment", "Error", e);
movieJsonStr = null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e("PlaceholderFragment", "Error closing stream", e);
}
}
}
try {
return getMovieData(movieJsonStr);
} catch (JSONException e) {
Log.e(LOG_CAT, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(List<Movie> movies){
if(movies != null){
movieAdapter.clear();
for(Movie movieData : movies){
movieAdapter.add(movieData);
}
}
}
}
}

Put these 2 lines inside your onPostExecute() in Async.
movieAdapter = new MovieAdapter(getActivity(), movieList);
listView.setAdapter(movieAdapter);
AsyncTask runs in Background Thread. It gets the data from json after few seconds. But your adapter is called few milli seconds after your fragment is created.
So the data from the Json will not be there when you are setting the adapter.
Calling it in onPostExecute solves this problem as the adatpter is set after Json data is retrieved from the server!
Hope it helps a bit.

You are printing size of movieList (movieList.size()) much before movieList() is getting populated. It will never print "Hello" "1" in debugger. The asynctask will fill data in movieList much later than your movieList.size() check code in OnCreateView()
Anyways, after the below code
for(Movie movieData : movies)
{
movieAdapter.add(movieData);
}
you need to insert this bit:
listView.setAdapter(movieAdapter);
You are populating the adapter but not setting it to your listView in your onPostExecute() in your getMovieData Asynctask.

It looks like on post execute you are clearing the List that your adapter is using to populate the listview, then adding in new items to the list. However, in order to update the view after that happens, you need to call notifyDataSetChanged(); after updating the list
#Override
protected void onPostExecute(List<Movie> movies){
if(movies != null){
movieAdapter.clear();
for(Movie movieData : movies){
movieAdapter.add(movieData);
}
movieAdapter.notifyDataSetChanged();
}
}

android update custom view in asynctask

Ok, I have a custom view which plays gifs from the internet. Therefor I need to add an url to my view to download the gif. But I can't seem to update my custom view inside my asynctask. I need to add an url string to my custom view gifView.setUrl(). It works in the onCreate Class but it gives me null in asynctask.
Oncreate class
GifView gifView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle extras = getIntent().getExtras();
id = extras.getInt("id");
String idStr = String.valueOf(id);
String extension = extras.getString("extension");
if(extension.equals(".gif")){
setContentView(R.layout.activity_post_gif);
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
gifView = (GifView)findViewById(R.id.gifview);
titleStr = (TextView)findViewById(R.id.titleTXT);
postInfo = (TextView)findViewById(R.id.infoTXT);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
//the url
new getJsonInfoGif().execute("http://www.website.com/jsonApi");
}else{
Asynctask
public class getJsonInfoGif extends AsyncTask<String, Void, String>{
#Override
protected void onPreExecute() {
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("loading post...");
progressDialog.show();
}
#Override
protected String doInBackground(String... strings) {
return GET(strings[0]);
}
#Override
protected void onPostExecute(String res) {
try {
JSONObject jsonObject = new JSONObject("{'postinfo':[" + res + "]}");
JSONArray jsonArray = jsonObject.getJSONArray("postinfo");
JSONObject obj = jsonArray.getJSONObject(0);
//post title
titleStr.setText(obj.getString("name"));
//category and maker full name
//large image
JSONObject imgObj = obj.getJSONObject("thumbnails");
gifView.setUrl("http://www.website.com/my.gif");
} catch (JSONException e) {
e.printStackTrace();
}
if (progressDialog != null) {
progressDialog.dismiss();
}
}
}
GifView.java
public void setUrl(String urlStr){
this.urlStr = urlStr;
invalidate();
requestLayout();
}
public String getUrl(){
return this.urlStr;
}
public void init(final Context context)throws IOException{
setFocusable(true);
movie = null;
movieWidth = 0;
movieHeight = 0;
movieDuration = 0;
final Thread thread = new Thread(new Runnable() {
#Override
public void run(){
try{
Log.d("DEBUG", "URL" + urlStr);
URL url = new URL(urlStr);
try {
HttpURLConnection http = (HttpURLConnection) url.openConnection();
inputStream = http.getInputStream();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
movie = Movie.decodeStream(inputStream);
movieWidth = movie.width();
movieHeight = movie.height();
movieDuration = movie.duration();
((PostActivity) context).runOnUiThread(new Runnable() {
#Override
public void run() {
invalidate();
requestLayout();
}
});
} catch (Exception e) {
e.printStackTrace();
}
}catch (Exception e){
e.printStackTrace();
}
}
});
thread.start();
}
Here is the Log from the url, it gives me null if I add the url inside my asynctask in Activity.
11-07 14:41:58.821 5674-6076/svenmobile.tools.showcase D/DEBUG﹕ URLnull
What I want to know is what the problem is and how to solve it if possible.
Thanks in advance, Sven

Maybe you called init() before setUrl().
You can pass it the url in the contructor, or public void init(final Context context, String urlStr)throws IOException{
I also suggest you to move all that network code to doInBackground

Gridview is refreshed from start when scrollbar reaches end

This happens while loading data in gridview. This is my fragment containing scroll listener over gridview. But whenever i reload the data then whole gridview reload and scroll starts from top not from where the data is loaded. I am using single gridview.
public class Women_Ethnic_Fragment extends Fragment {
private static String url = "http://------/-------";
private int mVisibleThreshold = 5;
private int mCurrentPage = 0;
private int mPreviousTotal = 0;
private boolean mLoading = true;
private boolean mLastPage = false;
public Women_Ethnic_Fragment() {
}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(
R.layout.gridview_fragment, container,
false);
setRetainInstance(true);
arrayList = new ArrayList<Items>();
gridView = (GridView) rootView.findViewById(R.id.gridView1);
new LoadData().execute(url);
//scrolling portion
gridView.setOnScrollListener(new OnScrollListener() {
#Override
public void onScroll(AbsListView view,
int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
if (mLoading) {
if (totalItemCount > mPreviousTotal) {
mLoading = false;
mPreviousTotal = totalItemCount;
mCurrentPage++;
if (mCurrentPage + 1 > 50) {
mLastPage = true;
}
}
}
if (!mLastPage
&& !mLoading
&& (totalItemCount - visibleItemCount) <= (firstVisibleItem + mVisibleThreshold)) {
//new asynctask called
new LoadData()
.execute("http://-------/---------");
mLoading = true;
}
}
#Override
public void onScrollStateChanged(AbsListView view,
int scrollState) {
}
});
return rootView;
}
//my asynctask
private class LoadData extends AsyncTask<String,
Void, Void> {
#Override
protected void onPostExecute(Void result) {
tp.dismiss();
adap = new Grid_View_Adatper(getActivity().getApplicationContext(),
arrayList);
gridView.setAdapter(adap);
super.onPostExecute(result);
}
#Override
protected void onPreExecute() {
tp = new TransparentProgressDialog(getActivity(),
R.drawable.spinner);
tp.setCancelable(false);
tp.setCanceledOnTouchOutside(false);
tp.show();
super.onPreExecute();
}
#Override
protected Void doInBackground(String... urls) {
try {
HttpClient client = new DefaultHttpClient();
HttpGet httpget = new HttpGet(urls[0]);
HttpResponse response = client.execute(httpget);
HttpEntity entity = response.getEntity();
String data = EntityUtils.toString(entity);
JSONArray json = new JSONArray(data);
for (int i = 0; i < json.length(); i++) {
JSONObject e = json.getJSONObject(i);
String name = e.getString("name");
String price = e.getString("price");
String image = e.getString("image");
String code = e.getString("sku");
tems = new Items(name, price, image, code);
arrayList.add(tems);
}
} catch (JSONException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
} catch (IOException e) {
} catch (RuntimeException e) {
}
return null;
}
}
Please help someone.
Thanks in advane.

The problem is you instantiate adapter over and over again. Instead check your adapter first, if it is not null, then set your data, then notify dataset changes.
if (adapter == null) {
adapter = new GridViewAdapter...
gridView.setAdapter(adapter)
}
// list refers the list inside in your adapter
list.addAll(newList); // or do your implementation
adapter.notifyDataSetChanged();