Develop Reference

Cannot fetch data from api to Gridview in fragment

if i using extends Activity it works normally. But when i move the code to fragment extends Fragment the progress bar is never stop and the data is never show up and there is no error to.
Frag_Country_List.java
public class Frag_Country_List extends Fragment implements DB_FetchDataListener {
private String CountryFlag;
private String CountryName;
private ProgressDialog dialog;
private GridView myGridview;
public Frag_Country_List() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.frag_country_list, container, false);
}
public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
// do your variables initialisations here except Views!!!
}
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
return true;
}
public void onViewCreated(#NonNull View view, Bundle savedInstanceState){ super.onViewCreated(view, savedInstanceState);
myGridview = (GridView)view.findViewById(R.id.countryGridView);
initView();
/*myGridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
OpenDialog();
}
});*/
}
private void initView() {
dialog = ProgressDialog.show(this.getContext(), "", "Loading...");
String url = "http://example.com/get_country.php";
DB_FetchDataTask task = new DB_FetchDataTask(this);
task.execute(url);
}
#Override
public void onFetchComplete(List<DB_Application> data) {
if(dialog != null) dialog.dismiss();
DB_ApplicationAdapter adapter = new DB_ApplicationAdapter(this.getContext(), data);
myGridview.setAdapter(adapter);
}
#Override
public void onFetchFailure(String msg) {
if(dialog != null) dialog.dismiss();
Toast.makeText(this.getContext(), msg, Toast.LENGTH_LONG).show();
}
}
DB_FetchDataTask.java
public class DB_FetchDataTask extends AsyncTask<String, Void, String>{
private final DB_FetchDataListener listener;
private String msg;
public DB_FetchDataTask(DB_FetchDataListener listener) {
this.listener = listener;
}
#Override
protected String doInBackground(String... params) {
if(params == null) return null;
// get url from params
String url = params[0];
try {
// create http connection
HttpClient client = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
// connect
HttpResponse response = client.execute(httpget);
// get response
HttpEntity entity = response.getEntity();
if(entity == null) {
msg = "No response from server";
return null;
}
// get response content and convert it to json string
InputStream is = entity.getContent();
return streamToString(is);
}
catch(IOException e){
msg = "No Network Connection";
}
return null;
}
#Override
protected void onPostExecute(String sJson) {
if(sJson == null) {
if(listener != null) listener.onFetchFailure(msg);
return;
}
try {
// convert json string to json array
JSONArray aJson = new JSONArray(sJson);
// create apps list
List<DB_Application> apps = new ArrayList<DB_Application>();
for(int i=0; i<aJson.length(); i++) {
JSONObject json = aJson.getJSONObject(i);
DB_Application app = new DB_Application();
app.setCountry(json.getString("_country"));
app.setFlag(json.getString("_flag"));
// add the app to apps list
apps.add(app);
}
//notify the activity that fetch data has been complete
if(listener != null) listener.onFetchComplete(apps);
} catch (JSONException e) {
msg = "Invalid response";
if(listener != null) listener.onFetchFailure(msg);
return;
}
}
/**
* This function will convert response stream into json string
* #param is respons string
* #return json string
* #throws IOException
*/
public String streamToString(final InputStream is) throws IOException{
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line).append("\n");
}
}
catch (IOException e) {
throw e;
}
finally {
try {
is.close();
}
catch (IOException e) {
throw e;
}
}
return sb.toString();
}
}
tell me if you need more information.
Logcat
11-27 13:54:06.007 1934-1994/com.mysql.sample E/Surface: getSlotFromBufferLocked: unknown buffer: 0xaaa89aa0
11-27 13:54:06.177 1934-1934/com.mysql.sample E/SysUtils: ApplicationContext is null in ApplicationStatus
11-27 13:54:06.185 1934-1934/com.mysql.sample E/libEGL: validate_display:255 error 3008 (EGL_BAD_DISPLAY)
11-27 13:54:06.185 1934-1934/com.mysql.sample E/libEGL: validate_display:255 error 3008 (EGL_BAD_DISPLAY)
11-27 13:54:06.215 1934-1934/com.mysql.sample E/DataReductionProxySettingListener: No DRP key due to exception:java.lang.ClassNotFoundException: com.android.webview.chromium.Drp

Try moving your onViewCreated code to onCreateView method:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.frag_country_list, container, false);
myGridview = (GridView)view.findViewById(R.id.countryGridView);
initView();
return view;
}

I am trying to show data using api . but data is not showing in custom listView . list is empty

I am trying to show data in custom listView using API
there is no error but data is not shown in custom list .i made separate
class for asyncTask ,Adapters and model.
code of asyncTask is
public class CourseOutlinesTask extends AsyncTask<String, String, String> {
ProgressDialog dialog;
Context context;
private ArrayList<CourseModel> postList = new ArrayList<CourseModel>();
private ListView listView;
private View root;
TrainerCourseAdapter adapter;
String json_string;
#Override
protected void onPreExecute() {
}
#Override
protected String 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);
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException 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(String result) {
super.onPostExecute(result);
//close process dialog
if (this.dialog != null) {
this.dialog.dismiss();
}
//parse json
try {
JSONObject jsonParse = new JSONObject(result);
JSONArray query = jsonParse.getJSONArray("courses");
for (int i = 0; i < query.length(); i++) {
try {
JSONObject jsonParser = query.getJSONObject(i);
CourseModel post = new CourseModel();
post.setId(jsonParser.getInt("id"));
post.setTitle(jsonParser.getString("title"));
post.setStatus(jsonParser.getString("status"));
post.setDescription(jsonParser.getString("description"));
System.out.println(post.getStatus()+"asdadasdad");
System.out.println(post);
postList.add(post);
TrainerCourseAdapter adapter = new TrainerCourseAdapter(context,postList);
}catch (Exception e) {
System.out.println(e);
}
// Parsing json
post.setDescription(obj.getString("description"));
// ****Handle CreationDate-Object
// Genre is json array
}
} else {
MyAppUtil.getToast(getApplicationContext(), message);
}*/
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
code of my adapter class is
public class TrainerCourseAdapter extends BaseAdapter {
private List list;
private Context context;
private static LayoutInflater inflater = null;
String [] cName;
String [] cDetail;
String [] created;
String [] cStatus;
TextView c_name,c_detail,c_date,c_status;
ArrayList<CourseModel> itemList;
Context mcontext;
public TrainerCourseAdapter(Context context,List list) {
mcontext = context;
itemList = (ArrayList<CourseModel>) list;
}
#Override
public int getCount() {
return itemList.size();
}
#Override
public Object getItem(int i) {
return i;
}
#Override
public long getItemId(int i) {
return i;
}
public void setItemList(ArrayList<CourseModel> itemList) {
this.itemList = itemList;
}
public class Holder
{
TextView c_name;
TextView c_detail;
TextView c_date ;
Button c_status;
}
#Override
public View getView(final int i, View view, ViewGroup viewGroup) {
Holder holder = new Holder();
View rowView;
rowView = inflater.inflate(R.layout.row_courses_list, viewGroup,false);
this.c_name = (TextView) rowView.findViewById(R.id.txt_courseName);
this.c_detail = (TextView) rowView.findViewById(R.id.txt_courseDetail);
this.c_date = (TextView) rowView.findViewById(R.id.txt_courseDate);
this.c_status = (Button) rowView.findViewById(R.id.btn_courseStatus);
System.out.println("Mudassir Don");
final CourseModel data = itemList.get(i);
this.c_name.setText(data.getTitle());
this.c_detail.setText(data.getDescription());
this.c_status.setText(data.getStatus());
this.c_date.setText(data.getId());
System.out.println(c_date);
rowView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Toast.makeText(context, "You Clicked "+ cName[i], Toast.LENGTH_LONG).show();
}
});
return rowView;
}
}
code of activity is
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_course_outlines);
CourseOutlinesTask task = new CourseOutlinesTask();
task.execute("http://mantis.vu.edu.pk/bridging_the_gap/public/viewCourseOutlines");
mylist = task.viewResult();
listView = (ListView) findViewById(R.id.course_listView);
listView.setAdapter(new TrainerCourseAdapter(CourseOutlinesActivity.this,mylist ) {
});

You need to assign your custom Adapter to listView.
yourListView.setAdapter(yourAdapter);
In your case, inside onPostExecute method of CourseOutlinesTask you should write it.
TrainerCourseAdapter adapter = new TrainerCourseAdapter(context,postList);
listView = (ListView) findViewById(R.id.course_listView);
listview.setAdapter(adapter);
Hope this helps.

You need to write a interface and get response in your activity and set adapter to list view
like.
TrainerCourseAdapter adapter = new TrainerCourseAdapter(context,postList);
listView = (ListView) findViewById(R.id.course_listView);
listview.setAdapter(adapter);

You can use callBack interface to get itemArraylist data to your activity class.
After getting itemlist data in activity class you can set adapter to listview.
TrainerCourseAdapter adapter = new TrainerCourseAdapter(context, postList);
listView = (ListView) findViewById(R.id.course_listView);
listview.setAdapter(adapter);
// You can create interface in your CourseOutlinesClass with two method onSuccess() and onFailure() and in onPostExecute() send arraylist data using this interface to activity , then set adapter to fill data in listview.

Use the below code:-
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_course_outlines);
listView = (ListView) findViewById(R.id.course_listView);
new CourseOutlinesTask().execute("http://mantis.vu.edu.pk/bridging_the_gap/public/viewCourseOutlines");
}
and in postExecute of your AsyncTask setAdapter to listView
TrainerCourseAdapter adapter = new TrainerCourseAdapter(context,postList);
listView.setAdapter(adapter);

Insert in listView an image from json url

I'm new in android. I have a problem about loading the image from Json Url to ListView. ListView works only without image.
This is my json url:
{"infoBooks":[{"user_name":"carlo","title":"Title: Il potere del cane\nAuthor\/s: Don Winslow","author":"","urlImage":"https:\/\/books.google.it\/books\/content?id=qiLanQEACAAJ&printsec=frontcover&img=1&zoom=1&source=gbs_api"},{"user_name":"ff","title":"Title: Incontro con la storia. Con espansione online. Per la Scuola media\nAuthor\/s: Luisa Benucci","author":"","urlImage":"https:\/\/books.google.it\/books\/content?id=qTzFSgAACAAJ&printsec=frontcover&img=1&zoom=1&source=gbs_api"}]}
My SearchBooks.java :
public class SearchBooks extends AppCompatActivity {
ListView mListView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search_books);
String strUrl = "http://192.168.1.118:8888/webappdb/listViewBooks.php";
DownloadTask downloadTask = new DownloadTask();
downloadTask.execute(strUrl);
mListView = (ListView) findViewById(R.id.listView);
}
private String downloadUrl (String strUrl) throws IOException{
String data = "";
InputStream iStream = null;
try {
URL url = new URL(strUrl);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.connect();
iStream = urlConnection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line);
}
data = sb.toString();
br.close();
}catch (Exception e){
Log.d("Exception while downloading url", e.toString());
}finally {
iStream.close();
}
return data;
}
private class DownloadTask extends AsyncTask<String, Integer, String>{
String data = null;
#Override
protected String doInBackground(String... url) {
try {
data = downloadUrl(url[0]);
} catch (IOException e) {
Log.d("Background Task", e.toString());
}
return data;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();
listViewLoaderTask.execute(result);
}
}
private class ListViewLoaderTask extends AsyncTask<String, Void, SimpleAdapter>{
JSONObject jObject;
#Override
protected SimpleAdapter doInBackground(String... strJson) {
try {
jObject = new JSONObject(strJson[0]);
customAdapter customAdapter = new customAdapter();
customAdapter.parse(jObject);
} catch (JSONException e) {
Log.d("JSON Exception1", e.toString());
}
customAdapter customAdapter = new customAdapter();
List<HashMap<String, Object>> books = null;
try {
books = customAdapter.parse(jObject);
} catch (Exception e){
Log.d("Exception", e.toString());
}
String infoFrom[] = {"user_name", "details"};
int infoTo[] = {R.id.user_name_search, R.id.bookDescriptionSearch};
SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), books, R.layout.row_list_books, infoFrom, infoTo);
return adapter;
}
#Override
protected void onPostExecute(SimpleAdapter adapter) {
mListView.setAdapter(adapter);
for (int i = 0; i < adapter.getCount(); i++){
HashMap<String, Object> hm = (HashMap<String, Object>) adapter.getItem(i);
String imgUrl = (String) hm.get("urlImage");
ImageLoaderTask imageLoaderTask = new ImageLoaderTask();
HashMap<String, Object> hmDownload = new HashMap<String, Object>();
hm.put("urlImage", imgUrl);
hm.put("position", i);
imageLoaderTask.execute();
}
}
}
private class ImageLoaderTask extends AsyncTask<HashMap<String, Object>, Void, HashMap<String, Object>>{
#Override
protected HashMap<String, Object> doInBackground(HashMap<String, Object>... hm) {
InputStream iStream = null;
String imgUrl = (String) hm[0].get("urlImage");
int position = (Integer) hm[0].get("position");
URL url;
try {
url = new URL(imgUrl);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.connect();
iStream = urlConnection.getInputStream();
File cacheDirectory = getBaseContext().getCacheDir();
File tmpFile = new File (cacheDirectory.getPath() + "/wpta_" + position + ".jpeg");
FileOutputStream fOutputStream = new FileOutputStream(tmpFile);
Bitmap b = BitmapFactory.decodeStream(iStream);
b.compress(Bitmap.CompressFormat.JPEG, 100, fOutputStream);
fOutputStream.flush();
fOutputStream.close();
HashMap<String, Object> hmBitmap = new HashMap<String, Object>();
hmBitmap.put("launcherImage", tmpFile.getPath());
hmBitmap.put("position", position);
return hmBitmap;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(HashMap<String, Object> result) {
String path = (String) result.get("launcherImage");
int position = (Integer) result.get("position");
SimpleAdapter simpleAdapter = (SimpleAdapter) mListView.getAdapter();
HashMap<String, Object> hm = (HashMap<String, Object>) simpleAdapter.getItem(position);
hm.put("launcherImage", path);
simpleAdapter.notifyDataSetChanged();
}
}
}
this is my customAdapter.java :
public class customAdapter{
public List<HashMap<String, Object>> parse(JSONObject JObject) {
JSONArray infoBooks = null;
try {
infoBooks = JObject.getJSONArray("infoBooks");
} catch (JSONException e) {
e.printStackTrace();
}
return getBooks(infoBooks);
}
private List<HashMap<String, Object>> getBooks(JSONArray infoBooks){
int booksCount = infoBooks.length();
List<HashMap<String, Object>> bookList = new ArrayList<HashMap<String, Object>>();
HashMap<String, Object> book;
for(int i = 0; i < booksCount; i++) {
try {
book = getBook((JSONObject) infoBooks.get(i));
bookList.add(book);
} catch (JSONException e) {
e.printStackTrace();
}
}
return bookList;
}
private HashMap<String, Object> getBook(JSONObject jBook){
HashMap<String, Object> book = new HashMap<String, Object>();
String user_name = "";
String title = "";
String author = "";
String urlImage = "";
try {
user_name = jBook.getString("user_name");
title = jBook.getString("title");
author = jBook.getString("author");
urlImage = jBook.getString("urlImage");
String details = "Title: " + title + "\n" +
"Author/s: " + author;
book.put("user_name", user_name);
book.put("details", details);
book.put("launcherImage", R.mipmap.ic_launcher);
book.put("urlImage", urlImage);
} catch (JSONException e) {
e.printStackTrace();
}
return book;
}
}
This is my logcat :
03-10 08:56:13.194 969-1433/? E/PersonaManagerService: inState(): stateMachine is null !!
03-10 08:56:13.994 969-1585/? E/PersonaManagerService: inState(): stateMachine is null !!
03-10 08:56:14.134 5005-5562/gamingproject.sellmybooks E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #4
Process: gamingproject.sellmybooks, PID: 5005
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.ArrayIndexOutOfBoundsException: length=0; index=0
at gamingproject.sellmybooks.SearchBooks$ImageLoaderTask.doInBackground(SearchBooks.java:176)
at gamingproject.sellmybooks.SearchBooks$ImageLoaderTask.doInBackground(SearchBooks.java:169)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
at java.lang.Thread.run(Thread.java:818) 
03-10 08:56:14.244 969-1049/? E/InputDispatcher: channel '14e67292 gamingproject.sellmybooks/gamingproject.sellmybooks.Profile (server)' ~ Channel is unrecoverably broken and will be disposed!
03-10 08:56:14.254 969-1207/? E/ActivityManager: checkUser: useridlist=null, currentuser=0
03-10 08:56:14.254 969-1207/? E/ActivityManager: checkUser: useridlist=null, currentuser=0
03-10 08:56:14.254 969-1207/? E/ActivityManager: checkUser: useridlist=null, currentuser=0
03-10 08:56:14.254 969-1207/? E/ActivityManager: checkUser: useridlist=null, currentuser=0
03-10 08:56:14.264 5566-5566/? E/Zygote: v2
03-10 08:56:14.274 5566-5566/? E/SELinux: [DEBUG] get_category: variable seinfo: default sensitivity: NULL, cateogry: NULL
03-10 08:56:14.774 270-270/? E/SMD: DCD OFF
03-10 08:56:17.784 270-270/? E/SMD: DCD OFF
Thank you in advance.

Why are you making the code so complex ? Keep it simple.
I have a Demo code. Maybe it can help you.
Just Create a Model Class Which you Require. Other things are the same.
public class MainActivity extends AppCompatActivity {
private Button btnHit;
private HttpURLConnection connection = null;
private URL url;
private BufferedReader reader = null;
private StringBuffer buffer;
private ListView lvMovies;
private ProgressDialog dialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dialog = new ProgressDialog(this);
dialog.setIndeterminate(true);
dialog.setCancelable(false);
dialog.setMessage("Loading !! Please wait..");
DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
.cacheInMemory(true)
.cacheOnDisk(true)
.build();
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
.defaultDisplayImageOptions(defaultOptions)
.build();
ImageLoader.getInstance().init(config);
lvMovies = (ListView) findViewById(R.id.lvMovies);
new JSONTask().execute("http://jsonparsing.parseapp.com/jsonData/moviesData.txt");
}
public class JSONTask extends AsyncTask<String, String, List<MovieModel>> {
#Override
protected void onPreExecute() {
super.onPreExecute();
dialog.show();
}
#Override
protected List<MovieModel> doInBackground(String... params) {
try {
url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("movies");
List<MovieModel> movieModelList = new ArrayList<>();
Gson gson = new Gson();
for (int i = 0; i < parentArray.length(); i++) {
JSONObject finalObject = parentArray.getJSONObject(i);
MovieModel movieModel = gson.fromJson(finalObject.toString(), MovieModel.class);
movieModelList.add(movieModel);
}
return movieModelList;
} 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<MovieModel> result) {
super.onPostExecute(result);
dialog.dismiss();
MovieAdapter adapter = new MovieAdapter(getApplicationContext(), R.layout.row, result);
lvMovies.setAdapter(adapter);
// TODO Need to set Data on List
}
}
public class MovieAdapter extends ArrayAdapter {
private List<MovieModel> movieModelList;
private int resource;
private LayoutInflater inflater;
public MovieAdapter(Context context, int resource, List<MovieModel> objects) {
super(context, resource, objects);
movieModelList = 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.ivMovieIcon = (ImageView) convertView.findViewById(R.id.ivIcon);
holder.tvMovie = (TextView) convertView.findViewById(R.id.tvMovie);
holder.tvTagline = (TextView) convertView.findViewById(R.id.tvTagLine);
holder.tvYear = (TextView) convertView.findViewById(R.id.tvYear);
holder.tvDuration = (TextView) convertView.findViewById(R.id.tvDuration);
holder.tvDirector = (TextView) convertView.findViewById(R.id.tvDirector);
holder.rbMovieRating = (RatingBar) convertView.findViewById(R.id.rbMovie);
holder.tvCast = (TextView) convertView.findViewById(R.id.tvCast);
holder.tvStory = (TextView) convertView.findViewById(R.id.tvStory);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
final ProgressBar progressBar = (ProgressBar) convertView.findViewById(R.id.progressBar);
ImageLoader.getInstance().displayImage(movieModelList.get(position).getImage(), holder.ivMovieIcon, new ImageLoadingListener() {
#Override
public void onLoadingStarted(String imageUri, View view) {
progressBar.setVisibility(View.VISIBLE);
}
#Override
public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
progressBar.setVisibility(View.GONE);
}
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
progressBar.setVisibility(View.GONE);
}
#Override
public void onLoadingCancelled(String imageUri, View view) {
progressBar.setVisibility(View.GONE);
}
});
holder.tvMovie.setText(movieModelList.get(position).getMovie());
holder.tvTagline.setText(movieModelList.get(position).getTagline());
holder.tvYear.setText("Year : " + movieModelList.get(position).getYear());
holder.tvDuration.setText(movieModelList.get(position).getDuration());
holder.tvDirector.setText(movieModelList.get(position).getDirector());
// Rating Bar
holder.rbMovieRating.setRating(movieModelList.get(position).getRating() / 2);
Log.v("Rating is", "" + movieModelList.get(position).getRating() / 2);
StringBuffer stringBuffer = new StringBuffer();
for (MovieModel.Cast cast : movieModelList.get(position).getCastList()) {
stringBuffer.append(cast.getName() + ", ");
}
holder.tvCast.setText(stringBuffer);
holder.tvStory.setText(movieModelList.get(position).getStory());
return convertView;
}
class ViewHolder {
private ImageView ivMovieIcon;
private TextView tvMovie;
private TextView tvTagline;
private TextView tvYear;
private TextView tvDuration;
private TextView tvDirector;
private RatingBar rbMovieRating;
private TextView tvCast;
private TextView tvStory;
}
}
}

Why JSON parser not working on Android?

I have an app which downloads YouTube JSON data. The code works perfectly in a desktop app, but not in android (the list is null when trying to iterate through it). Here's my code which matters:
public String DownloadJSONData(){
BufferedReader reader = null;
String webc = "";
try{
URL url = new URL("http://gdata.youtube.com/feeds/api/users/thecovery/uploads?v=2&alt=json");
reader = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[] chars = new char[1024];
while((read = reader.read(chars)) != -1){
buffer.append(chars,0,read);
}
webc = buffer.toString();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
return webc;
} catch (IOException e) {
e.printStackTrace();
}
}
}
System.out.println(webc);
return webc;
}
public void GetData() throws JSONException {
JSONObject obj = new JSONObject(DownloadJSONData());
JSONArray feed = obj.getJSONObject("feed").getJSONArray("entry");
for(int i = 0; i < feed.length(); i++){
EPISODE_NAME.add(feed.getJSONObject(i).getJSONObject("title").getString("$t"));
EPISODE_LINK.add(feed.getJSONObject(i).getJSONArray("link").getJSONObject(0).getString("href"));
}
ListView episodes = (ListView) findViewById(R.id.episodeChooser);
ArrayAdapter<String> episodesSource = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,EPISODE_NAME);
}
}
In the onCreate method, I call the GetData() method, and I try to set the adapter to the ListView from the EPISODE_NAME ArrayList, but it's null. I also tried to set the adapter after the method, in onCreate, but no luck. Anyone can help?

It works fine
Add Below permission in Manifest.xml
<uses-permission android:name="android.permission.INTERNET"/>
ManiActivity.java
public class MainActivity extends Activity {
private ListView listView;
private List<FeedsDTO> feedsList = new ArrayList<FeedsDTO>();
private FeedsDTO dto = null;
private BackgroundThread backgroundThread;
private CustomAdapter customAdapter = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listview);
backgroundThread = new BackgroundThread();
backgroundThread.execute();
}
private void setListViewAdapter(){
customAdapter = new CustomAdapter(this, R.layout.listitem, feedsList);
listView.setAdapter(customAdapter);
}
private class BackgroundThread extends AsyncTask<Void, Void, String> {
private ProgressDialog progressBar = null;
#Override
protected void onPreExecute() {
super.onPreExecute();
progressBar = new ProgressDialog(MainActivity.this);
progressBar.setCancelable(false);
progressBar.show();
}
#Override
protected String doInBackground(Void... params) {
BufferedReader reader = null;
String webc = "";
try{
URL url = new URL("http://gdata.youtube.com/feeds/api/users/thecovery/uploads?v=2&alt=json");
reader = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[] chars = new char[1024];
while((read = reader.read(chars)) != -1){
buffer.append(chars,0,read);
}
webc = buffer.toString();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
return webc;
} catch (IOException e) {
e.printStackTrace();
}
}
}
System.out.println(webc);
return webc;
}
#Override
protected void onPostExecute(String result) {
JSONObject obj;
try {
obj = new JSONObject(result);
JSONArray feed = obj.getJSONObject("feed").getJSONArray("entry");
Log.i("=======", "========="+feed.length());
for(int i = 0; i < feed.length(); i++){
dto = new FeedsDTO();
dto.setName(feed.getJSONObject(i).getJSONObject("title").getString("$t"));
dto.setLink(feed.getJSONObject(i).getJSONArray("link").getJSONObject(0).getString("href"));
feedsList.add(dto);
dto = null;
}
Log.i("=======LIst Size", "========="+feedsList.size());
progressBar.dismiss();
setListViewAdapter();
} catch (JSONException e) {
e.printStackTrace();
}
super.onPostExecute(result);
}
}
}
CustomAdapter.java
public class CustomAdapter extends ArrayAdapter<FeedsDTO>{
private LayoutInflater inflater;
private int layoutID;
public CustomAdapter(Context cntx, int resource, List<FeedsDTO> objects) {
super(cntx, resource, objects);
this.inflater =(LayoutInflater) cntx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.layoutID = resource;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
try {
ViewHolder holder = null;
if (convertView == null) {
convertView = inflater.inflate(layoutID, null);
holder = new ViewHolder();
holder.NameTV = (TextView) convertView.findViewById(R.id.textview);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
FeedsDTO feedsDTO = getItem(position);
holder.NameTV.setText(feedsDTO.getName());
feedsDTO = null;
} catch (Exception e) {
e.printStackTrace();
}
return convertView;
}
private class ViewHolder{
TextView NameTV;
}
}
FeedsDTO.java
public class FeedsDTO {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
private String link;
}
listitem.xlm:-
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</TextView>
I hope this code will work perfectly

Most apps include several different activities that allow the user to
perform different actions. Whether an activity is the main activity
that's created when the user clicks your app icon or a different
activity that your app starts in response to a user action, the system
creates every new instance of Activity by calling its onCreate()
method.
You must implement the onCreate() method to perform basic application
startup logic that should happen only once for the entire life of the
activity. For example, your implementation of onCreate() should define
the user interface and possibly instantiate some class-scope
variables.
For example, the following example of the onCreate() method shows some
code that performs some fundamental setup for the activity, such as
declaring the user interface (defined in an XML layout file), defining
member variables, and configuring some of the UI.
You are basically mixing stuff left and right. First create your Interface in the onCreate() and do the logic in onStart().
You should read the android lifecycle. See here

Android strange error

I have made an listview application, then i created a new one with fragments and want to implement listview to fragments. But when i do i got an strange error.
public class Fragment1 extends Fragment {
private ArrayList<FeedItem> feedList = null;
private ProgressBar progressbar = null;
private ListView feedListView = null;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.list_row_layout, container, false);
progressbar = (ProgressBar)rootView.findViewById(R.id.progressBar);
String url = "";
new DownloadFilesTask().execute(url);
return rootView;
}
public void updateList() {
feedListView= (ListView)getActivity().findViewById(R.id.custom_list);
feedListView.setVisibility(View.VISIBLE);
progressbar.setVisibility(View.GONE);
**feedListView.setAdapter(new CustomListAdapter(this, feedList));**
feedListView.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
Object o = feedListView.getItemAtPosition(position);
FeedItem newsData = (FeedItem) o;
**Intent intent = new Intent(FeedListActivity.this, FeedDetailsActivity.class);**
intent.putExtra("feed", newsData);
startActivity(intent);
}
});
}
public class DownloadFilesTask extends AsyncTask<String, Integer, Void> {
#Override
protected void onProgressUpdate(Integer... values) {
}
#Override
protected void onPostExecute(Void result) {
if (null != feedList) {
updateList();
}
}
#Override
protected Void doInBackground(String... params) {
String url = params[0];
// getting JSON string from URL
JSONObject json = getJSONFromUrl(url);
//parsing json data
parseJson(json);
return null;
}
}
public JSONObject getJSONFromUrl(String url) {
InputStream is = null;
JSONObject jObj = null;
String json = null;
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
public void parseJson(JSONObject json) {
try {
// parsing json object
if (json.getString("status").equalsIgnoreCase("ok")) {
JSONArray posts = json.getJSONArray("posts");
feedList = new ArrayList<FeedItem>();
for (int i = 0; i < posts.length(); i++) {
JSONObject post = (JSONObject) posts.getJSONObject(i);
FeedItem item = new FeedItem();
item.setTitle(post.getString("title"));
item.setDate(post.getString("description"));
item.setId(post.getString("id"));
item.setUrl(post.getString("url"));
item.setContent(post.getString("description"));
JSONArray attachments = post.getJSONArray("attachments");
if (null != attachments && attachments.length() > 0) {
JSONObject attachment = attachments.getJSONObject(0);
if (attachment != null)
item.setAttachmentUrl(attachment.getString("url"));
}
feedList.add(item);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Problems are on this lines
feedListView.setAdapter(new CustomListAdapter(this, feedList));
Intent intent = new Intent(FeedListActivity.this, FeedDetailsActivity.class);
Multiple markers at this line
- Line breakpoint:Fragment1 [line: 57] - updateList()
- The constructor CustomListAdapter(Fragment1, ArrayList<FeedItem>) is
undefined
No enclosing instance of the type FeedListActivity is accessible in scope
CustomListAdapter:
public class CustomListAdapter extends BaseAdapter {
private ArrayList<FeedItem> listData;
private LayoutInflater layoutInflater;
private Context mContext;
public CustomListAdapter(Context context, ArrayList<FeedItem> listData) {
this.listData = listData;
layoutInflater = LayoutInflater.from(context);
mContext = context;
}
#Override
public int getCount() {
return listData.size();
}
#Override
public Object getItem(int position) {
return listData.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.list_row_layout, null);
holder = new ViewHolder();
holder.headlineView = (TextView) convertView.findViewById(R.id.title);
holder.reportedDateView = (TextView) convertView.findViewById(R.id.date);
holder.imageView = (ImageView) convertView.findViewById(R.id.thumbImage);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
FeedItem newsItem = (FeedItem) listData.get(position);
holder.headlineView.setText(newsItem.getTitle());
holder.reportedDateView.setText(newsItem.getDate());
if (holder.imageView != null) {
new ImageDownloaderTask(holder.imageView).execute(newsItem.getAttachmentUrl());
}
return convertView;
}
static class ViewHolder {
TextView headlineView;
TextView reportedDateView;
ImageView imageView;
}
}

in this line feedListView.setAdapter(new CustomListAdapter(this, feedList)); just replace this with getActivity();