Develop Reference

Use Async Task in oncreateview

Is there a way to overwrite the "week_kg" variable with the async task in the oncreateview method?
The async task overwrites the variable, but the View is already created and doesn't contain the new value.
It's a Rest Communications with a Node.js Server and a Mysql database.
public class Feedback extends Fragment {
private RecyclerView mRecylcerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
public String username = "ilovenature";
public double week_kg;
String resturl = "http://192.168.178.199:3000/"; //ip
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_feedback, container, false);
new HttpGet().execute(resturl + "user/" + username);
ArrayList < Feedback_inhalt > feedback_inhalt = new ArrayList<>();
feedback_inhalt.add(new Feedback_inhalt(R.mipmap.ic_plastic_color, "Verwertungskosten", "kg eingespart", week_kg));
mRecylcerView = view.findViewById(R.id.feedback_view);
mRecylcerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this.getActivity());
mAdapter = new FeedbackAdapter(feedback_inhalt);
mRecylcerView.setLayoutManager(mLayoutManager);
mRecylcerView.setAdapter(mAdapter);
return view;
}
public class HttpGet extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String...strURLs) {
URL url;
String output;
HttpURLConnection conn;
try {
url = new URL(strURLs[0]);
conn = (HttpURLConnection) url.openConnection();
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
while ((output = br.readLine()) != null) {
sb.append(output);
}
return sb.toString();
} catch (IOException e) {
return "Unable to retrieve web page. URL may be invalid.";
}
}
#Override
protected void onPostExecute(String result) {
try {
JSONArray jsonArray = new JSONArray(result);
JSONObject jsonObject = jsonArray.getJSONObject(0);
week_kg = jsonObject.getDouble("wochenkilogramm");
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}

The onCreateView() method is only called once when the view is created.
However, you can refresh your RecyclerView once your AsyncTask has finished executing. To achieve this, add the newly fetched data to your ArrayList feedback_halt and then call notifyDataSetChanged() on your adapter.
When you call notifyDataSetChanged(), the views will be refreshed based on the data in your ArrayList.
So, inside onPostExecute() after you have set the value of week_kg:
feedback_inhalt.add(new Feedback_inhalt(R.mipmap.ic_plastic_color, "Verwertungskosten", "kg eingespart", week_kg));
mAdapter.notifyDatSetChanged()
Finally, the notifyDataSetChanged() method should only be called from a UI thread but the onPostExecute() method runs on the UI thread by design so you are good to go :-)

Json paring with Recycler view

Here I am trying to display the name and price of the test.
and I'm taking a recycler view to do the same using the JET Parsing GET method.
But I'm not getting anything in my business and showing myself black there.
here is my code
please help me find the solution.
Model class
public class TestListsModel {
public String test_price;
public String testlist_id;
public String test_name;
}
This is my Adapter:
public class AdapterTestList extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private Context context;
private LayoutInflater inflater;
List<TestListsModel> data= Collections.emptyList();
TestListsModel current;
int currentPos=0;
// create constructor to innitilize context and data sent from MainActivity
public AdapterTestList(Context context, List<TestListsModel> data){
this.context=context;
inflater= LayoutInflater.from(context);
this.data=data;
}
// Inflate the layout when viewholder created
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view=inflater.inflate(R.layout.test_list_row, parent,false);
MyHolder holder=new MyHolder(view);
return holder;
}
// Bind data
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// Get current position of item in recyclerview to bind data and assign values from list
MyHolder myHolder= (MyHolder) holder;
TestListsModel current=data.get(position);
myHolder.testName.setText(current.test_name);
myHolder.testPrice.setText( current.test_price);
// load image into imageview using glide
/* Glide.with(context).load("http://192.168.1.7/test/images/" + current.fishImage)
.placeholder(R.drawable.ic_img_error)
.error(R.drawable.ic_img_error)
.into(myHolder.ivFish);*/
}
// return total item from List
#Override
public int getItemCount() {
return data.size();
}
class MyHolder extends RecyclerView.ViewHolder{
TextView testName;
TextView testPrice;
// create constructor to get widget reference
public MyHolder(View itemView) {
super(itemView);
testName = (TextView) itemView.findViewById(R.id.test_name);
testPrice = (TextView) itemView.findViewById(R.id.price_name);
}
}
}
This is my Activity Class:
public class HealthServicesActivity extends AppCompatActivity implements View.OnClickListener {
SharePreferenceManager<LoginModel> sharePreferenceManager;
// CONNECTION_TIMEOUT and READ_TIMEOUT are in milliseconds
public static final int CONNECTION_TIMEOUT = 10000;
public static final int READ_TIMEOUT = 15000;
private RecyclerView testListRecylerView;
private AdapterTestList mAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_health_services);
ButterKnife.bind(this);
sharePreferenceManager = new SharePreferenceManager<>(getApplicationContext());
dayTimeDisplay();
new AsyncLogin().execute();
}
private class AsyncLogin extends AsyncTask<String, String, String> {
//ProgressDialog pdLoading = new ProgressDialog(getApplicationContext());
HttpURLConnection conn;
URL url = null;
#Override
protected void onPreExecute() {
super.onPreExecute();
//this method will be running on UI thread
/* pdLoading.setMessage("\tLoading...");
pdLoading.setCancelable(false);
pdLoading.show();*/
}
#Override
protected String doInBackground(String... params) {
try {
String url_test="http://192.168.1.80/aoplnew/api/users/gettestlist/"+sharePreferenceManager.getUserLoginData(LoginModel.class).getResult().getCenterId();
// Enter URL address where your json file resides
// Even you can make call to php file which returns json data
//url = new URL("http://192.168.1.7/test/example.json");
url = new URL(url_test);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return e.toString();
}
try {
// Setup HttpURLConnection class to send and receive data from php and mysql
conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(READ_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("GET");
// setDoOutput to true as we recieve data from json file
conn.setDoOutput(true);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return e1.toString();
}
try {
int response_code = conn.getResponseCode();
// Check if successful connection made
if (response_code == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
// Pass data to onPostExecute method
return (result.toString());
} else {
return ("[]");
}
} catch (IOException e) {
e.printStackTrace();
return e.toString();
} finally {
conn.disconnect();
}
}
#Override
protected void onPostExecute(String result) {
//this method will be running on UI thread
//pdLoading.dismiss();
List<TestListsModel> data=new ArrayList<>();
//pdLoading.dismiss();
try {
JSONArray jArray = new JSONArray(result);
// Extract data from json and store into ArrayList as class objects
for(int i=0;i<jArray.length();i++){
JSONObject json_data = jArray.getJSONObject(i);
TestListsModel testData = new TestListsModel();
testData.testlist_id= json_data.getString("testlist_id");
testData.test_name= json_data.getString("test_name");
testData.test_price= json_data.getString("test_price");
data.add(testData);
}
// Setup and Handover data to recyclerview
testListRecylerView = (RecyclerView)findViewById(R.id.test_list_recycler_view);
mAdapter = new AdapterTestList(HealthServicesActivity.this, data);
testListRecylerView.setAdapter(mAdapter);
testListRecylerView.setLayoutManager(new LinearLayoutManager(HealthServicesActivity.this));
} catch (JSONException e) {
Toast.makeText(HealthServicesActivity.this, e.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
Thanks in advance for any answer!

You need to set the setLayoutManager before the setting the adapter like below. In your code, you have setAdapter() before the setLayoutManager therefore your adapter not set properly.
Refer this for the further explanation https://developer.android.com/guide/topics/ui/layout/recyclerview
testListRecylerView = (RecyclerView)findViewById(R.id.test_list_recycler_view);
mAdapter = new AdapterTestList(HealthServicesActivity.this, data);
/**
* SET THE LAYOUT MANAGER BEFORE SETTING THE ADAPTER
*/
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(HealthServicesActivity.this);
testListRecylerView.setLayoutManager(mLayoutManager);
testListRecylerView.setItemAnimator(new DefaultItemAnimator());
/**
* AND THAN SET THE ADAPTER
*/
testListRecylerView.setAdapter(mAdapter);

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);

Results not showing in the ListView Android

I've been working on an android app ... I am stuck at a point ... after getting the JSON data from the internet I am having trouble to show it in the ListView ... Below is my code ...
public class MainListActivityFragment extends Fragment {
protected String[] mBlogPostTitles;
protected JSONObject mBlogData;
public static final String LOG_TAG = MainListActivityFragment.class.getSimpleName();
public static ArrayAdapter<String> titleAdapter;
public MainListActivityFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_list, container, false);
if(isNetworkAvailable()) {
GetBlogPost getBlogPost = new GetBlogPost();
getBlogPost.execute();
} else {
Toast.makeText(getContext(),"No Network Available", Toast.LENGTH_LONG).show();
}
List<String> blogTitles = new ArrayList<>(Arrays.asList(mBlogPostTitles));
titleAdapter = new ArrayAdapter<>(
getActivity(),
R.layout.name_lst_view,
R.id.name_list_view_textview,
blogTitles
);
ListView listView = (ListView) rootView.findViewById(R.id.listview_name);
listView.setAdapter(titleAdapter);
return rootView;
}
private boolean isNetworkAvailable() {
ConnectivityManager manager = (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
boolean isAvailable = false;
if (networkInfo != null && networkInfo.isConnected()){
isAvailable = true;
}
return isAvailable;
}
private void updateList() {
if(mBlogData == null){
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Oopps");
builder.setMessage("There was an error accessing the blog ...");
builder.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
}
}
public class GetBlogPost extends AsyncTask<Object, Void, JSONObject> {
public final int NUMBER_OF_POSTS = 5;
int responseCode = -1;
JSONObject jsonResponse = null;
#Override
protected JSONObject doInBackground(Object... params) {
try {
URL blogFeedUrl = new URL("http://www.example.com/api/get_category_posts/?slug=americancuisines&count="+NUMBER_OF_POSTS);
HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
connection.setRequestMethod("GET");
connection.connect();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK){
InputStream inputStream = connection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
String blogDataJsonStr = buffer.toString();
jsonResponse = new JSONObject(blogDataJsonStr);
}else {
Log.i(LOG_TAG, "Unsuccessful HTTP Response Code: " + responseCode);
}
}
catch (MalformedURLException e){
Log.e(LOG_TAG,"Exception Caught: ",e);
}
catch (IOException e) {
Log.e(LOG_TAG, "IO Exception Caught: ",e);
}
catch (Exception e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
return jsonResponse;
}
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
mBlogData = result;
updateList();
}
}
}
From the above code you can see that i am getting that data through doInBackground method of AsyncTask ... Data is coming through perfectly as I can see through the logcat ... The issue is somewhere in this method which I can't seem to figure out ..
private void updateList() {
if(mBlogData == null){
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Oopps");
builder.setMessage("There was an error accessing the blog ...");
builder.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
}
}
The above method is called in onPostExecute I mean if i print to logcat within this method I can see the results being printed but when I try to show those results in the onCreateView method results don't show up not even in the logcat ... Any help will be appreciated ... Thanks

Change your code as following:
public class MainListActivityFragment extends Fragment {
protected String[] mBlogPostTitles;
protected JSONObject mBlogData;
public static final String LOG_TAG = MainListActivityFragment.class.getSimpleName();
public static ArrayAdapter<String> titleAdapter;
ListView listView;
public MainListActivityFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_list, container, false);
listView = (ListView) rootView.findViewById(R.id.listview_name);
if(isNetworkAvailable()) {
GetBlogPost getBlogPost = new GetBlogPost();
getBlogPost.execute();
} else {
Toast.makeText(getContext(),"No Network Available", Toast.LENGTH_LONG).show();
}
return rootView;
}
private void updateList() {
if(mBlogData == null){
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Oopps");
builder.setMessage("There was an error accessing the blog ...");
builder.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
}
}
public class GetBlogPost extends AsyncTask<Object, Void, JSONObject> {
public final int NUMBER_OF_POSTS = 5;
int responseCode = -1;
JSONObject jsonResponse = null;
#Override
protected JSONObject doInBackground(Object... params) {
try {
URL blogFeedUrl = new URL("http://www.example.com/api/get_category_posts/?slug=americancuisines&count="+NUMBER_OF_POSTS);
HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
connection.setRequestMethod("GET");
connection.connect();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK){
InputStream inputStream = connection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
String blogDataJsonStr = buffer.toString();
jsonResponse = new JSONObject(blogDataJsonStr);
}else {
Log.i(LOG_TAG, "Unsuccessful HTTP Response Code: " + responseCode);
}
}
catch (MalformedURLException e){
Log.e(LOG_TAG,"Exception Caught: ",e);
}
catch (IOException e) {
Log.e(LOG_TAG, "IO Exception Caught: ",e);
}
catch (Exception e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
return jsonResponse;
}
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
mBlogData = result;
updateList();
List<String> blogTitles = new ArrayList<>(Arrays.asList(mBlogPostTitles));
titleAdapter = new ArrayAdapter<String>(
getActivity(),
R.layout.name_list_view,
R.id.name_list_view_textview,
blogTitles
);
listView.setAdapter(titleAdapter);
}
}
}

Use same array list in both update and initialize so globally declare a single array list and update it in updateList() method,
Try like this,
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];//remove this and use the
//same as you are using in adapter
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
titleAdapter.notifyDataSetChanged();//here
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
OR even you can use in onPostExecute
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
mBlogData = result;
updateList();
titleAdapter.notifyDataSetChanged();//here
}

find the listview : ListView listView = (ListView) rootView.findViewById(R.id.listview_name); before calling
GetBlogPost getBlogPost = new GetBlogPost();
getBlogPost.execute();
and put this line listView.setAdapter(titleAdapter); in your onPostExecute method.

Android listview not getting populated with data

I am new to Android Studio and have a simple android view i am working on. A button click makes a call to the foursquare API and get backresults for starbucks around my location that I parse and am trying to set to the adapter for the listbox on the same view. If i put a breakpoint in the OnPostExecute() I see the mFoursquare adapter that I set for the listview has two json string results in the mFoursquareAdapter , I even call the
mFoursquareAdapter.notifyDataSetChanged();
in it but the view does not get refreshed with the results. I have posted the code below. Can anyone please point out what I am doing wrong or need to change since I already have the results and need to get this done...Your help and feedback very much appreciated! thanks
public class FoursquareInfoFragment extends android.app.Fragment {
private ArrayAdapter<String> mFoursquareAdapter;
public FoursquareInfoFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Dummy data for the ListView. Here's the sample weekly forecast
String[] data = {
"Sample Foursquare Data",
};
List<String> foursquareList = new ArrayList<String>(Arrays.asList(data));
mFoursquareAdapter = new ArrayAdapter<String>(
getActivity(), // the current context ie the activity
R.layout.fragment_my, // the name of the layout Id
R.id.textViewFoursquare, // the Id of the TextView to populate
foursquareList);
View rootView = inflater.inflate(R.layout.fragment_my, container, false);
//View resultsView = inflater.inflate(R.layout.results, container, false);
View resultsView = inflater.inflate(R.layout.fragment_my, container, false);
ListView listView = (ListView) resultsView.findViewById(R.id.listview_FoursquareInfo);
listView.setAdapter(mFoursquareAdapter);
Button btnGetFoursquareData = (Button) rootView.findViewById(R.id.btnFoursquare);
btnGetFoursquareData.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FetchFoursquareDataTask fetch = new FetchFoursquareDataTask();
fetch.execute("Starbucks");
}
});
return rootView;
}
public class FetchFoursquareDataTask extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchFoursquareDataTask.class.getSimpleName();
#Override
protected void onPostExecute(String[] result) {
if (result != null) {
mFoursquareAdapter.clear();
for (String ItemStr : result) {
mFoursquareAdapter.add(ItemStr);
}
mFoursquareAdapter.notifyDataSetChanged();
}
}
#Override
protected String[] doInBackground(String... params) {
// If there's no venue category, theres nothing to look up. Verify the size of the params.
if (params.length == 0) {
return null;
}
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String foursquareJsonStr = null;
try {
// Build Foursquare URI with Parameters
final String FOURSQUARE_BASE_URL =
"https://api.foursquare.com/v2/venues/search";
final String client_id = "client_id";
final String client_secret = "client_secret";
final String v = "20130815";
final String near = "Dunwoody, Ga";
final String query = "Starbucks";
final String limit = "2";
Uri builtUri = Uri.parse(FOURSQUARE_BASE_URL).buildUpon()
.appendQueryParameter("client_id", client_id)
.appendQueryParameter("client_secret", client_secret)
.appendQueryParameter("v", v)
.appendQueryParameter("near", near)
.appendQueryParameter("query", query)
.appendQueryParameter("limit", limit)
.build();
URL url = new URL(builtUri.toString());
// Create the request to Foursquare, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
foursquareJsonStr = null;
return null;
}
foursquareJsonStr = buffer.toString();
Log.v(LOG_TAG, "Foursquare JSON String: " + foursquareJsonStr);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the fpursquare data, there's no point in attempting
// to parse it.
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e("PlaceholderFragment", "Error closing stream", e);
}
}
}
String[] list = new String[]{"", ""};
try {
JSONObject foursquareJson = new JSONObject(foursquareJsonStr);
JSONObject responseObject = (JSONObject) foursquareJson.get("response");
JSONArray foursquareArray = responseObject.getJSONArray("venues");
list = new String[foursquareArray.length()];
for (int i = 0; i < foursquareArray.length(); i++) {
list[i] = foursquareArray.get(i).toString();
}
return list;
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
} finally {
Log.e(LOG_TAG, "ba");
return list;
}
}
}
}

This
mFoursquareAdapter.add(ItemStr);
Should be
foursquareList.add(ItemStr)
And you'll need to declare foursquareList properly (as a field).
You should also declare your Adapter as a field variable as well, just in case you need to reference it later