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ViewPager Not getting Images from server

I am using ViewPager in my app and fetch the data(Images) from server(with JSON). Even if runs smoothly no image is shown in the viewpager.
I read so many tutorial regarding this, but nobody solve my problem. Please tell me where i am wrong...
Here is my code:
view_pager.xml
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="40dp" />
image_view.xml
<ImageView
android:id="#+id/image_adapter"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"/>
ViewPager_Adapter.java
public class ViewPager_Adapter extends PagerAdapter {
private String urls;
private LayoutInflater inflater;
private Context context;
ArrayList<String> mylist;
public ViewPager_Adapter(Context context, ArrayList<String> mylist) {
this.context = context;
this.urls = urls;
this.mylist = mylist;
inflater = LayoutInflater.from(context);
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
#Override
public int getCount() {
return mylist.size();
}
#Override
public Object instantiateItem(ViewGroup view, int position) {
View imageLayout = inflater.inflate(R.layout.image_view, null);
assert imageLayout != null;
final ImageView imageView = (ImageView) imageLayout.findViewById(R.id.image_adapter);
Glide.with(context)
.load(mylist.get(position))
.into(imageView);
view.addView(imageLayout,0);
return imageLayout;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view.equals(object);
}
#Override
public void restoreState(Parcelable state, ClassLoader loader) {
}
#Override
public Parcelable saveState() {
return null;
}
}
View_Pager.Java
public class View_Pager extends Fragment {
private static ViewPager mPager;
JSONArray responsearray = null;
String imageOne;
private static final String TAG_PHOTO_ONE = "Gallery_Full";
ArrayList<String> myList;
HashMap<String, String> get;
ViewPager_Adapter viewpager_adapter;
LinearLayout addimages;
int REQUEST_CODE = 100;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.view_pager, null);
mPager = view.findViewById(R.id.viewpager);
new GetImages().execute(true);
return view;
}
class GetImages extends AsyncTask<Boolean, Void, String> {
#Override
protected String doInBackground(Boolean... booleans) {
ImageApi imageApi = new ImageApi();
String result = null;
try {
result = imageApi.galleryget(sharedPreferences.getString("id", ""));
JSONObject object = new JSONObject(result);
if (object.getString("error").equalsIgnoreCase("false")) {
responsearray = object.getJSONArray("response");
return "true";
} else {
String errormsg = object.getString(result);
return errormsg;
}
} catch (ApiException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if (s != null) {
if (s.equalsIgnoreCase("true")) {
showList(responsearray);
}
}
}
}
public void showList(final JSONArray responsearray) {
try {
for (int i = 0; i < responsearray.length(); i++) {
JSONObject responseObject = responsearray.getJSONObject(i);
Log.e("COUNT" + i, String.valueOf(responseObject));
imageOne = responseObject.getString(TAG_PHOTO_ONE);
get = new HashMap<>();
get.put(TAG_PHOTO_ONE, imageOne);
myList = new ArrayList<>();
myList.add(String.valueOf(get));
}
viewpager_adapter = new ViewPager_Adapter(getActivity(), myList);
String test = String.valueOf(myList);
String imgpath = getString(R.string.imgpath);
String finalimgpath = imgpath + imageOne;
Log.e("FINALPATH", finalimgpath);
} catch (JSONException e) {
e.printStackTrace();
}
mPager.setAdapter(viewpager_adapter);
viewpager_adapter.notifyDataSetChanged();
}
}

Use this code for showList() as you are not populating you're arrayList properly the data is being over write in one position .
So , what you have to do is initialize it out side of for loop .
public void showList(final JSONArray responsearray) {
try {
//here
myList = new ArrayList<>();
for (int i = 0; i < responsearray.length(); i++) {
JSONObject responseObject = responsearray.getJSONObject(i);
Log.e("COUNT" + i, String.valueOf(responseObject));
imageOne = responseObject.getString(TAG_PHOTO_ONE);
get = new HashMap<>();
get.put(TAG_PHOTO_ONE, imageOne);
myList.add(String.valueOf(get));
}
viewpager_adapter = new ViewPager_Adapter(getActivity(), myList);
String test = String.valueOf(myList);
String imgpath = getString(R.string.imgpath);
String finalimgpath = imgpath + imageOne;
Log.e("FINALPATH", finalimgpath);
} catch (JSONException e) {
e.printStackTrace();
}
mPager.setAdapter(viewpager_adapter);
viewpager_adapter.notifyDataSetChanged();
}
Edit
Also if your final image path is as below then you have to update your code in adapter for image path as follow.
Update position in view.addView() too.
String test = String.valueOf(mylist.get(position));
String imgpath = getString(R.string.imgpath);
String finalimgpath = imgpath + test;
Glide.with(context)
.load(finalimgpath)
.into(imageView);
view.addView(imageLayout,position);
return imageLayout;

In your For loop you are initialising your list everytime
for (int i = 0; i < responsearray.length(); i++) {
JSONObject responseObject = responsearray.getJSONObject(i);
Log.e("COUNT" + i, String.valueOf(responseObject));
imageOne = responseObject.getString(TAG_PHOTO_ONE);
get = new HashMap<>();
get.put(TAG_PHOTO_ONE, imageOne);
myList = new ArrayList<>(); // THIS IS WRONG. don't initialise every time
myList.add(String.valueOf(get)); // THIS IS ALSO WRONG. you are adding hashmap object to list
}
So make your for loop like this
myList = new ArrayList<>();
for (int i = 0; i < responsearray.length(); i++) {
JSONObject responseObject = responsearray.getJSONObject(i);
Log.e("COUNT" + i, String.valueOf(responseObject));
imageOne = responseObject.getString(TAG_PHOTO_ONE);
get = new HashMap<>();
get.put(TAG_PHOTO_ONE, imageOne);
myList.add(imageOne);
}

Endless RecyclerView with Asynctask using EndlessRecyclerOnScrollListener

I have an activity which searches for a query (using async task and server side PHP) and gives out a list in recycler view, Now i want to implement endless/infinite scrolling when user reaches bottom. I have tried to do that using EndlessScrollListener. There are two problems i need help with.
first, the new list recreates itself instead of appending to the old list.
second, the current_page int variable keeps its value from the previous search and scroll, means when running AsyncTask for second time, the current_page int variable still retains the value from the first time and does not reset.
public class MainActivity extends AppCompatActivity {
// CONNECTION_TIMEOUT and READ_TIMEOUT are in milliseconds
public static final int CONNECTION_TIMEOUT = 10000;
public static final int READ_TIMEOUT = 15000;
private RecyclerView mRVFish;
private AdapterFish mAdapter;
private LinearLayoutManager mLayoutManager;
private String searchQuery;
SearchView searchView = null;
private String query;
private EndlessRecyclerOnScrollListener mScrollListener = null;
private SwipeRefreshLayout mSwipeRefreshLayout = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRVFish = (RecyclerView) findViewById(R.id.fishPriceList);
mLayoutManager = new LinearLayoutManager(MainActivity.this);
mRVFish.setLayoutManager(mLayoutManager);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// adds item to action bar
getMenuInflater().inflate(R.menu.search_main, menu);
// Get Search item from action bar and Get Search service
MenuItem searchItem = menu.findItem(R.id.action_search);
SearchManager searchManager = (SearchManager) MainActivity.this.getSystemService(Context.SEARCH_SERVICE);
if (searchItem != null) {
searchView = (SearchView) searchItem.getActionView();
}
if (searchView != null) {
searchView.setSearchableInfo(searchManager.getSearchableInfo(MainActivity.this.getComponentName()));
searchView.setIconified(false);
}
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}
// Every time when you press search button on keypad an Activity is recreated which in turn calls this function
#Override
protected void onNewIntent(Intent intent) {
// Get search query and create object of class AsyncFetch
if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
query = intent.getStringExtra(SearchManager.QUERY);
if (searchView != null) {
searchView.clearFocus();
}
int startrow =0;
String type="";
String filetype="";
AsyncFetch myTask = new AsyncFetch(query, startrow, type, filetype);
myTask.execute();
mScrollListener = new EndlessRecyclerOnScrollListener(mLayoutManager) {
#Override
public void onLoadMore(int current_page) {
int startrow=current_page;
String type="";
String filetype="";
AsyncFetch myTask = new AsyncFetch(query, startrow, type, filetype);
myTask.execute();
}
};
mRVFish.addOnScrollListener(mScrollListener);
// enable pull down to refresh
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
int startrow =0;
String type="";
String filetype="";
AsyncFetch myTask = new AsyncFetch(query, startrow, type, filetype);
myTask.execute();
// after refresh is done, remember to call the following code
if (mSwipeRefreshLayout != null && mSwipeRefreshLayout.isRefreshing()) {
mSwipeRefreshLayout.setRefreshing(false); // This hides the spinner
}
}
});
}
}
// Create class AsyncFetch
private class AsyncFetch extends AsyncTask<String, String, String> {
ProgressDialog pdLoading = new ProgressDialog(MainActivity.this);
HttpURLConnection conn;
URL url = null;
String searchQuery;
int startrow;
String type;
String filetype;
public AsyncFetch(String searchQuery, int startrow, String type, String filetype){
this.searchQuery=searchQuery;
this.startrow = startrow;
this.type = type;
this.filetype=filetype;
}
#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 {
// Enter URL address where your php file resides
url = new URL("http://someurl/json/search.php");
} 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("POST");
// setDoInput and setDoOutput to true as we send and recieve data
conn.setDoInput(true);
conn.setDoOutput(true);
// add parameter to our above url
Uri.Builder builder = new Uri.Builder().appendQueryParameter("searchQuery", searchQuery).appendQueryParameter("startrow", String.valueOf(startrow));
String query = builder.build().getEncodedQuery();
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
conn.connect();
} 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("Connection error");
}
} 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<DataFish> data=new ArrayList<>();
pdLoading.dismiss();
if(result.equals("no rows")) {
Toast.makeText(MainActivity.this, "No Results found for entered query", Toast.LENGTH_LONG).show();
}else{
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);
DataFish fishData = new DataFish();
try {
fishData.fileName = URLDecoder.decode(json_data.getString("file"), "UTF-8");
} catch (Exception e) {
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
fishData.fileName=json_data.getString("file");
}
fishData.linkName = json_data.getString("link");
fishData.reg_date = json_data.getString("reg_date");
fishData.fileSize = json_data.getString("filesize");
data.add(fishData);
}
mAdapter = new AdapterFish(MainActivity.this, data);
mRVFish.setAdapter(mAdapter);
if(jArray.length()>19)
mScrollListener.setLoading(false);
else
mScrollListener.setLoading(true);
} catch (JSONException e) {
// You to understand what actually error is and handle it appropriately
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(MainActivity.this, result.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
}
EndlessRecyclerOnScrollListener.java
public abstract class EndlessRecyclerOnScrollListener extends
RecyclerView.OnScrollListener {
public static String TAG = EndlessRecyclerOnScrollListener.class.getSimpleName();
private int previousTotal = 0; // The total number of items in the dataset after the last load
private boolean loading = false; // True if we are still waiting for the last set of data to load.
private int visibleThreshold = 0; // The minimum amount of items to have below your current scroll position before loading more.
int firstVisibleItem, visibleItemCount, totalItemCount;
private int current_page = 20;
private LinearLayoutManager mLayoutManager;
public EndlessRecyclerOnScrollListener(LinearLayoutManager linearLayoutManager) {
this.mLayoutManager = linearLayoutManager;
}
#Override
public void onScrolled(RecyclerView mRVFish, int dx, int dy) {
super.onScrolled(mRVFish, dx, dy);
if(dy < 0) {
return;
}
// check for scroll down only
visibleItemCount = mRVFish.getChildCount();
totalItemCount = mLayoutManager.getItemCount();
firstVisibleItem = mLayoutManager.findFirstVisibleItemPosition();
// to make sure only one onLoadMore is triggered
synchronized (this) {
if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)) {
// End has been reached, Do something
current_page=current_page+20;
onLoadMore(current_page);
loading = true;
}
}
}
public void setLoading(boolean loading) {
this.loading = loading;
}
public abstract void onLoadMore(int current_page);
}

first, the new list recreates itself instead of appending to the old list.
If you set a new adapter you swap the content of the recycler view. I think you do it in the following code
mAdapter = new AdapterFish(MainActivity.this, data);
mRVFish.setAdapter(mAdapter);
To append the data you need to add new elements to the adapter's dataset (dataset where you get data to bind views in your adapter) and then call adapter.notifyDataSetChanged() or better adapter.notifyItemRangeInserted(int positionStart, int itemCount)
There are also a number of tools to optimize adding the elements, like DiffUtil
second, the current_page int variable keeps its value from the previous search and scroll, means when running AsyncTask for second time
Not sure what was library developer's idea here, but the easiest way would be to just create a method in the EndlessRecyclerOnScrollListener similar to:
public void resetPage() {
current_page = 20;
}
And call it before invoking new search.

Swipe Refresh freezes when executing async task

I'm encountering a problem, when I try running an asynchronous task on refresh using a swipe refresh layout it "freezes" and doesn't rotate. When the task is done it just disappears.
Here is my code:
HotActivityFragment.java:
public class HotActivityFragment extends Fragment {
ListView hotList;
SwipeRefreshLayout mSwipeRefreshLayout;
Context context;
SharedPreferences sharedPreferences;
HotListAdapter hotListAdapter;
public HotActivityFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_hot, container, false);
context = getContext();
mSwipeRefreshLayout = (SwipeRefreshLayout)view.findViewById(R.id.activity_main_swipe_refresh_layout);
hotList = (ListView)view.findViewById(R.id.hotListView);
hotList.setOnScrollListener(new EndlessScrollListener(getActivity()));
sharedPreferences = getActivity().getPreferences(Context.MODE_PRIVATE);
try {
ArrayList<ListTypeItem> initial_list = new DownloadPosts(getActivity()).execute().get();
this.hotListAdapter = new HotListAdapter(getContext(), initial_list);
hotList.setAdapter(hotListAdapter);
}catch(Exception e)
{
Log.d("Download Error", e.toString());
}
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
retrievePosts();
}
});
mSwipeRefreshLayout.setColorSchemeResources(R.color.accentColor, R.color.backgroundColor);
return view;
}
public void retrievePosts()
{
// showing refresh animation before making http call
mSwipeRefreshLayout.setRefreshing(true);
//shared preferences = empty
sharedPreferences.edit().putString("last_time_downloaded", "empty").commit();
try {
ArrayList<ListTypeItem> listItems = new DownloadPosts(getActivity(), mSwipeRefreshLayout).execute().get();
hotListAdapter.updateList(listItems);
hotListAdapter.notifyDataSetChanged();
} catch (Exception e) {
Log.d("Download Error", e.toString());
}
mSwipeRefreshLayout.setRefreshing(false);
//for testing purposes
// new Handler().postDelayed(new Runnable() {
// #Override public void run() {
// mSwipeRefreshLayout.setRefreshing(false);
// }
// }, 5000);
}
}
DownloadPosts.java:
public class DownloadPosts extends AsyncTask<Void, Void, ArrayList<ListTypeItem>> {
SharedPreferences sharedPreferences;
SwipeRefreshLayout swipeRefreshLayout;
public DownloadPosts(Activity activity)
{
this.sharedPreferences = activity.getPreferences(Context.MODE_PRIVATE);
}
public DownloadPosts(Activity activity, SwipeRefreshLayout swipeRefreshLayout)
{
this.sharedPreferences = activity.getPreferences(Context.MODE_PRIVATE);
this.swipeRefreshLayout = swipeRefreshLayout;
}
#Override
protected ArrayList<ListTypeItem> doInBackground(Void... args)
{
StringBuilder parsedString = new StringBuilder();
ArrayList<ListTypeItem> downloadList = new ArrayList<>();
StringBuilder str = new StringBuilder();
if(sharedPreferences.getBoolean("Thomas More",false))
{
str.append("190155257998823,");
}
String school_url = str.toString();
if(school_url.length() > 0)
{
school_url = school_url.substring(0, str.length()-1);
}
try{
String date = "";
//checken of opnieuw moet bepaald worden
// + in de adapter moet als gereload wordt last_time_downloaded == empty
if(!sharedPreferences.getString("last_time_downloaded","empty").equals("empty"))
{
String last_date = sharedPreferences.getString("last_time_downloaded","nothing");
last_date = last_date.replace(" ","T");
date= "&datum_last_posted=" + last_date;
}
URL url = new URL("http://localhost/getpostlist.php?school_post=" + school_url + date);
URLConnection conn = url.openConnection();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String json;
while((json = bufferedReader.readLine())!= null)
{
parsedString.append(json + "/n");
}
String s = parsedString.toString().trim();
//converten van string opgehaald via http naar jsonobject
JSONArray array = new JSONArray(s);
for(int i = 0; i < array.length(); i++)
{
JSONObject tempObj = array.getJSONObject(i);
School_WithoutImage tempSchool = new School_WithoutImage(tempObj.getString("school_id"),
tempObj.getString("post_message"),tempObj.getInt("views"),tempObj.getInt("likes")
,tempObj.getInt("post_id"),tempObj.getString("datum_posted"));
downloadList.add(tempSchool);
if(i == array.length()-1) {
sharedPreferences.edit().putString("last_time_downloaded",tempObj.getString("datum_posted")).commit();
}
}
JSONObject obj = array.getJSONObject(0);
}catch(Exception e)
{
Log.d("Exception", e.toString());
}
return downloadList;
}
#Override
protected void onPostExecute(ArrayList<ListTypeItem> result)
{
if(this.swipeRefreshLayout != null)
{
// swipeRefreshLayout.setRefreshing(false);
}
}
}
I have no idea why the swiperefreshview doesn't spin. Anyone has an idea?

Because the call to get():
.execute().get()
Forces the UI thread to wait for the AsyncTask to finish.
Instead you should look at doing this in the onPostExecute method:
protected void onPostExecute(ArrayList<ListTypeItem> listItems) {
hotListAdapter.updateList(listItems);
hotListAdapter.notifyDataSetChanged();
}

Because you are waiting for the result from asynctask by calling get just after execute. And further passing it to list.
You can use Local Broadcast Listener or can create an interface and can us that as callback, without freezing UI

Recyclerview+JSON+Fragment+Android

I'm trying to pass an Arraylist with Objects obtained from a JSON, and pass to another fragment in Android Studio.
Here is the class that i want to receive the array
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_car, container, false);
new AsyncTaskParseJson().execute();
mRecyclerView = (RecyclerView) view.findViewById(R.id.rv_list);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.addOnItemTouchListener(new RecyclerViewTouchListener( getActivity(), mRecyclerView, this ));
LinearLayoutManager llm = new LinearLayoutManager(getActivity());
llm.setOrientation(LinearLayoutManager.VERTICAL);
mRecyclerView.setLayoutManager(llm);
CarAdapter adapter = new CarAdapter(getActivity(), mList);
mRecyclerView.setAdapter( adapter );
return view;
}
That is my class that is creating the array:
public class AsyncTaskParseJson extends AsyncTask<String, String, String> {
final String TAG = "AsyncTaskParseJson.java";
String yourJsonStringUrl = "http://marciowelben.servidorturbo.net/getjson.php";
JSONArray dataJsonArr = null;
#Override
protected void onPreExecute() {}
#Override
protected String doInBackground(String... arg0) {
try {
JsonParser jParser = new JsonParser();
JSONObject json = jParser.getJSONFromUrl(yourJsonStringUrl);
dataJsonArr = json.getJSONArray("emp_info");
for (int i = 0; i < dataJsonArr.length(); i++) {
JSONObject c = dataJsonArr.getJSONObject(i);
// Storing each json item in variable
String firstname = c.getString("employee name");
String lastname = c.getString("employee no");
Car d = new Car(firstname, lastname, R.mipmap.ic_launcher );
listAux.add(d);
}
} catch (JSONException e) {
e.printStackTrace();
}
mList = listAux;
return null;
}
}
So i just want to populate my Recyclerview with this array.

Since you are adding the adapter first before waiting for the data to return you will have to call notifyDataSetChanged() for the adapter to redraw the list after it is done parsing. Another way of accomplishing this is waiting for the result to come back and then set the adapter. See below
public class MainActivity extends AppCompatActivity {
private static final String TAG = "RecyclerViewExample";
private List<FeedItem> feedItemList = new ArrayList<FeedItem>();
private RecyclerView mRecyclerView;
private MyRecyclerAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/* Initialize recyclerview */
mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
/*Downloading data from below url*/
final String url = "http://javatechig.com/api/get_category_posts/?dev=1&slug=android";
new AsyncHttpTask().execute(url);
}
public class AsyncHttpTask extends AsyncTask<String, Void, Integer> {
#Override
protected void onPreExecute() {
setProgressBarIndeterminateVisibility(true);
}
#Override
protected Integer doInBackground(String... params) {
InputStream inputStream = null;
Integer result = 0;
HttpURLConnection urlConnection = null;
try {
/* forming th java.net.URL object */
URL url = new URL(params[0]);
urlConnection = (HttpURLConnection) url.openConnection();
/* for Get request */
urlConnection.setRequestMethod("GET");
int statusCode = urlConnection.getResponseCode();
/* 200 represents HTTP OK */
if (statusCode == 200) {
BufferedReader r = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder response = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
response.append(line);
}
parseResult(response.toString());
result = 1; // Successful
}else{
result = 0; //"Failed to fetch data!";
}
} catch (Exception e) {
Log.d(TAG, e.getLocalizedMessage());
}
return result; //"Failed to fetch data!";
}
#Override
protected void onPostExecute(Integer result) {
setProgressBarIndeterminateVisibility(false);
/* Download complete. Lets update UI */
if (result == 1) {
adapter = new MyRecyclerAdapter(MainActivity.this, feedItemList);
mRecyclerView.setAdapter(adapter);
} else {
Log.e(TAG, "Failed to fetch data!");
}
}
}
private void parseResult(String result) {
try {
JSONObject response = new JSONObject(result);
JSONArray posts = response.optJSONArray("posts");
/*Initialize array if null*/
if (null == feedItemList) {
feedItemList = new ArrayList<FeedItem>();
}
for (int i = 0; i < posts.length(); i++) {
JSONObject post = posts.optJSONObject(i);
FeedItem item = new FeedItem();
item.setTitle(post.optString("title"));
item.setThumbnail(post.optString("thumbnail"));
feedItemList.add(item);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}

1.Design Recycleview in layout
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="10dp"
android:layout_weight="1"
/>
2.add dependency in gradle.build
compile 'com.android.support:recyclerview-v7:23.1.1'
3.Write the code in Activity
public class DoctorInformationActivity extends AppCompatActivity {
String URL="YOUR URL";
JSONArray Cities=null;
ArrayList<DocotorInformation> doctorList =new ArrayList<DocotorInformation>();
Sqlitedatabase sql;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.doctor_information_listview);
sql=new Sqlitedatabase(getApplicationContext());
ConnectivityManager connectivityManager
= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
if(activeNetworkInfo != null && activeNetworkInfo.isConnected())
{
Toast.makeText(getApplicationContext()," connect",Toast.LENGTH_LONG).show();
new JSONAsyncTask().execute();
}
else
{
ArrayList<DocotorInformation> listdata=sql.getAllContacts();
doctorList=listdata;
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
DoctorAdapter mAdapter = new DoctorAdapter(getApplicationContext(), doctorList);
recyclerView.setAdapter(mAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
Toast.makeText(getApplicationContext(),"Not connect",Toast.LENGTH_LONG).show();
}
}
private class JSONAsyncTask extends AsyncTask<String, Void, JSONArray> {
private ProgressDialog dialog = new ProgressDialog(DoctorInformationActivity.this);
#Override
protected void onPreExecute() {
this.dialog.setMessage("Please wait");
this.dialog.show();
}
#Override
protected JSONArray doInBackground(String... urls) {
try {
//------------------>>
HttpGet httppost = new HttpGet(URL);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(httppost);
// StatusLine stat = response.getStatusLine();
int status = response.getStatusLine().getStatusCode();
if (status == 200) {
HttpEntity entity = response.getEntity();
String data = EntityUtils.toString(entity);
JSONObject jsono = new JSONObject(data);
Cities = jsono.getJSONArray("SearchDoctorsData");
return Cities;
}
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return Cities;
}
protected void onPostExecute(JSONArray result) {
dialog.dismiss();
System.out.println(result);
for (int i = 0; i < result.length(); i++) {
JSONObject c = null;
try {
DocotorInformation doc=new DocotorInformation();
c = result.getJSONObject(i);
doc.setName(c.getString("DoctorName"));
doc.setNumber(c.getString("Mobile"));
doctorList.add(doc);
sql.insertData(doc);
} catch (JSONException e) {
e.printStackTrace();
}
}
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
DoctorAdapter mAdapter = new DoctorAdapter(getApplicationContext(), doctorList);
recyclerView.setAdapter(mAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
}
}
}
public class DoctorAdapter extends RecyclerView.Adapter<DoctorAdapter.ViewHolder> {
private ArrayList<DocotorInformation> countries;
Context con;
public DoctorAdapter(Context c ,ArrayList<DocotorInformation> countries) {
this.con=c;
this.countries = countries;
}
#Override
public DoctorAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.doctor_textviews, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(DoctorAdapter.ViewHolder viewHolder, int i) {
viewHolder.name.setText(countries.get(i).getName());
viewHolder.number.setText(countries.get(i).getNumber());
}
#Override
public int getItemCount() {
return countries.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
private TextView name,number;
public ViewHolder(View view) {
super(view);
name = (TextView)view.findViewById(R.id.name);
number = (TextView)view.findViewById(R.id.numebr);
}
}
}

Error in my logcat, after some refreshes on my list my app crashes

Posts.java
public class Posts extends Activity implements OnCheckedChangeListener {
private static final String TAG = "POSTS";
private static final int NULL_COUNTRY_CODE = 6;
private static final int POST_BACK_BTN = 7;
private static final int CHANGE = 8;
private String un;
private SimpleAdapter simpleAdpt;
private EditText post;
private RadioGroup radGrp;
private GPSTracker mGPS;
private PullToRefreshListView lv;
private String initial = "Se eida ";
private String code;
private String unm;
private String postui;
private String tmp;
private String idPost;
// The data to show
private List<Map<String, String>> postsList = new ArrayList<Map<String, String>>();
JSONArray array = null;
private static List<String> list = new ArrayList<String>();
private String pst;
private AlertDialogFragments adf;
private FragmentTransaction ft;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_posts);
initLocation();
if (code == null) {
ft = getFragmentManager().beginTransaction();
// Create and show the dialog.
adf = new AlertDialogFragments(NULL_COUNTRY_CODE);
adf.show(ft, "dialog");
}
init();
}
private HashMap<String, String> createPost(String key, String name) {
HashMap<String, String> post = new HashMap<String, String>();
post.put(key, name);
return post;
}
private void initLocation() {
mGPS = new GPSTracker(this);
final double mLat = mGPS.getLatitude();
final double mLong = mGPS.getLongitude();
getAddress(mLat, mLong);
}
private void getAddress(double mLat, double mLong) {
try {
Geocoder gcd = new Geocoder(this, Locale.getDefault());
List<Address> addresses = gcd.getFromLocation(mLat, mLong, 100);
if (addresses.size() > 0) {
addresses = gcd.getFromLocation(mLat, mLong, 1);
code = addresses.get(0).getCountryCode();
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
private void init() {
this.getWindow().setSoftInputMode(
WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
Intent i = getIntent();
un = i.getStringExtra("un");
post = (EditText) findViewById(R.id.lbl_txt);
radGrp = (RadioGroup) findViewById(R.id.rdg);
radGrp.setOnCheckedChangeListener(this);
// We get the ListView component from the layout
lv = (PullToRefreshListView) findViewById(R.id.listView);
// Set a listener to be invoked when the list should be refreshed.
((PullToRefreshListView) lv)
.setOnRefreshListener(new OnRefreshListener() {
#Override
public void onRefresh() {
((PullToRefreshListView) lv)
.setLastUpdated(new SimpleDateFormat(
"dd-MM-yyyy HH:mm").format(new Date()));
new GetData().execute();
}
});
simpleAdpt = new CustomAdapter(this, postsList,
android.R.layout.simple_list_item_1, new String[] { "post" },
new int[] { android.R.id.text1 });
new GetData().execute();
}
public class CustomAdapter extends SimpleAdapter {
HashMap<String, String> map = new HashMap<String, String>();
public CustomAdapter(Context context,
List<? extends Map<String, String>> data, int resource,
String[] from, int[] to) {
super(context, data, resource, from, to);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = super.getView(position, convertView, parent);
if (row != null) {
if (position % 2 == 0)
row.setBackgroundResource(R.drawable.listview_selector_even);
else
row.setBackgroundResource(R.drawable.listview_selector_odd);
}
return row;
}
}
private class GetData extends AsyncTask<String, String, String> {
private ProgressDialog progDailog;
#Override
protected void onPreExecute() {
super.onPreExecute();
progDailog = new ProgressDialog(Posts.this);
progDailog.setMessage("Loading...");
progDailog.setIndeterminate(false);
progDailog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progDailog.setCancelable(true);
progDailog.show();
}
#Override
protected String doInBackground(String... params) {
postsList.clear();
list.clear();
new Thread(new Runnable() {
public void run() {
//getting data from server and store into results
try {
array = new JSONArray(result);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0; i < array.length(); i++) {
JSONObject row = null;
try {
row = array.getJSONObject(i);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
unm = row.getString("Username");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
postui = row.getString("Post");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
tmp = row.getString("Timestamp");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
idPost = row.getString("Id");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
pst = unm + ":\n" + postui + "\n"
+ tmp.substring(0, tmp.length() - 2);
list.add(i, idPost);
postsList.add(createPost("post", pst));
}
runOnUiThread(new Runnable() {
#Override
public void run() {
lv.setSelector(R.drawable.row_pressed);
lv.setAdapter(simpleAdpt);
simpleAdpt.notifyDataSetChanged();
registerForContextMenu(lv);
}
});
}
}).start();
return null;
}
#Override
protected void onPostExecute(String unused) {
super.onPostExecute(unused);
simpleAdpt.notifyDataSetChanged();
progDailog.dismiss();
((PullToRefreshListView) lv).onRefreshComplete();
}
}
// We want to create a context Menu when the user long click on an item
#Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
AdapterContextMenuInfo aInfo = (AdapterContextMenuInfo) menuInfo;
// We know that each row in the adapter is a Map
HashMap<?, ?> map = (HashMap<?, ?>) simpleAdpt
.getItem(aInfo.position - 1);
String string = (String) map.get("post");
menu.setHeaderTitle("Options");
menu.add(1, 1, 1, "Share via:");
menu.add(1, 2, 2, "Copy");
menu.add(1, 3, 3, "Delete");
menu.add(1, 1, 1, "Share via:");
menu.add(1, 2, 2, "Copy");
}
// This method is called when user selects an Item in the Context menu
#SuppressWarnings("deprecation")
#Override
public boolean onContextItemSelected(MenuItem item) {
int itemId = item.getItemId();
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
.getMenuInfo();
switch (itemId) {
case 1:
// Share intent
String key = ((TextView) info.targetView).getText().toString();
// create the send intent
Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND);
// set the type
shareIntent.setType("text/plain");
// add a subject
shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT,
R.string.app_name);
// build the body of the message to be shared
String shareMessage = key.substring(0, key.length() - 20)
.substring(key.indexOf(":") + 2);
// add the message
shareIntent.putExtra(android.content.Intent.EXTRA_TEXT,
shareMessage);
// start the chooser for sharing
startActivity(Intent.createChooser(shareIntent, "Share via: "));
break;
case 2:
// Copy
String key1 = ((TextView) info.targetView).getText().toString();
int sdk = android.os.Build.VERSION.SDK_INT;
if (sdk < android.os.Build.VERSION_CODES.HONEYCOMB) {
android.text.ClipboardManager clipboard = (android.text.ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
clipboard.setText(key1.substring(0, key1.length() - 20)
.substring(key1.indexOf(":") + 2));
Toast.makeText(this, "Post copied.", Toast.LENGTH_SHORT).show();
} else {
android.content.ClipboardManager clipboard = (android.content.ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
android.content.ClipData clip = android.content.ClipData
.newPlainText("", key1.substring(0, key1.length() - 20)
.substring(key1.indexOf(":") + 2));
clipboard.setPrimaryClip(clip);
Toast.makeText(this, "Post copied.", Toast.LENGTH_SHORT).show();
}
break;
case 3:
// Delete
int index = info.position - 1;
//deletes a post
deletePost(list.get(index), this);
new GetData().execute();
break;
}
return true;
}
My Logcat output
The content of the adapter has changed but ListView did not receive a
notification. Make sure the content of your adapter is not modified
from a background thread, but only from the UI thread.

You are using postList as content for your adapter. Then you change that content in doInBackground(). You cannot do that.
Here's what you have to do. Gather the data in doInBackground() and return it. The result will be passed to onPostExecute. Then, in onPostExecute, change the adapter content and notify about the data change. onPostExecute() runs in the UI thread.
If you want to periodically update your AdapterView, use publishProgress.
You don't need to start a new Thread in doInBackground and you don't need to invoke any runOnUIThread method. It will work (especially the runOnUIThread part) but then you don't need the AsyncTask class.