Do not go to update the adapter. RecyclerView

There is a fragment code where for recyclerView I put my adapter rvDownloadAdapter If I fill the array before the adapter is initialized, then the elements are displayed in recyclerView works. As for example, I initially add one element to the array.

Then I call AsyncTask where I get data from the PHPFunction and in the PHPFunction class PHPFunction fill in the array and return it. But when onPostExecute update the adapter in onPostExecute it is not updated, I initially thought that the array was empty, but then I log the size of the array and it shows me that the size is four, ie array is not empty.

Here is the fragment code:

 public class DownloadCentrFragment extends Fragment { Context context; Resources resources; TabLayout tabLayout; ViewPager viewPager; List<View> pages = new ArrayList<View>(); List<String> titles = new ArrayList<String>(); ArrayList<itemGetServerList> itemGetServerInfos = new ArrayList<itemGetServerList>(); RVDownloadAdapter rvDownloadAdapter = null; public DownloadCentrFragment() {} public DownloadCentrFragment setInstance() { DownloadCentrFragment fragment = new DownloadCentrFragment(); return fragment; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_download_centr, container, false); context = this.getActivity().getApplicationContext(); resources = this.getActivity().getResources(); tabLayout = (TabLayout) view.findViewById(R.id.tabLayout); viewPager = (ViewPager) view.findViewById(R.id.viewPager); titles.add(resources.getString(R.string.text_UsersList)); titles.add(resources.getString(R.string.text_YouList)); View v1 = inflater.inflate(R.layout.fragment_home_download_centr, null); EditText SearchText = (EditText) v1.findViewById(R.id.SearchText); ImageView Search = (ImageView) v1.findViewById(R.id.Search); ImageView Filtr = (ImageView) v1.findViewById(R.id.Filtr); RecyclerView recyclerView = (RecyclerView) v1.findViewById(R.id.recycler_view); LinearLayoutManager llm = new LinearLayoutManager(view.getContext()); recyclerView.setLayoutManager(llm); itemGetServerInfos.add(new itemGetServerList("Таблица умножения на два", 228, 5, "7-9", "Таблица на два от тред до семи", "","","arif","", null)); rvDownloadAdapter = new RVDownloadAdapter(itemGetServerInfos, view.getContext()); recyclerView.setAdapter(new AlphaInAnimationAdapter(rvDownloadAdapter)); ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(view.getContext(),pages,titles); pages.add(v1); viewPager.setAdapter(viewPagerAdapter); tabLayout.setupWithViewPager(viewPager); new LoadInfoTask().execute(); return view; } class LoadInfoTask extends AsyncTask<Void, Void, Void> { @Override protected void onPreExecute() { super.onPreExecute(); } @Override protected Void doInBackground(Void... params) { itemGetServerInfos = new PHPFunction(resources, context).getInList(0,30); return null; } @Override protected void onPostExecute(Void result) { super.onPostExecute(result); rvDownloadAdapter.notifyDataSetChanged(); Log.d("myLog", itemGetServerInfos.size() + " sizes"); } } } 

rvDownloadAdapter

 public class RVDownloadAdapter extends RecyclerView.Adapter<RVDownloadAdapter.ViewHolder> { ArrayList<itemGetServerList> itemGetServerInfo = new ArrayList<itemGetServerList>(); Context context; public RVDownloadAdapter (ArrayList<itemGetServerList> itemGetServerInfoLoad, Context context) { this.itemGetServerInfo = itemGetServerInfoLoad; this.context = context; } public static class ViewHolder extends RecyclerView.ViewHolder { View view; CardView cardView; ImageView icon; TextView NameList; TextView Des; TextView Rating; TextView Age; ViewHolder(View itemView) { super(itemView); cardView = (CardView) itemView.findViewById(R.id.card_view); icon = (ImageView) itemView.findViewById(R.id.icon); NameList = (TextView) itemView.findViewById(R.id.nameList); Des = (TextView) itemView.findViewById(R.id.des); Rating = (TextView) itemView.findViewById(R.id.rating); Age = (TextView) itemView.findViewById(R.id.age); view = itemView; } } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_download_card, parent, false); ViewHolder vh = new ViewHolder(v); return vh; } @Override public void onBindViewHolder(final ViewHolder holder, final int position) { final itemGetServerList infoData = itemGetServerInfo.get(position); holder.NameList.setText(itemGetServerInfo.get(position).NameList); holder.Des.setText(itemGetServerInfo.get(position).Des); holder.Rating.setText(itemGetServerInfo.get(position).Rating + ""); holder.Age.setText(itemGetServerInfo.get(position).Age); switch (itemGetServerInfo.get(position).Tag) { case "orph": holder.icon.setImageDrawable(context.getResources().getDrawable(R.drawable.icon_orphographic)); break; case "arif": holder.icon.setImageDrawable(context.getResources().getDrawable(R.drawable.icon_arithmetic)); break; } } @Override public void onAttachedToRecyclerView(RecyclerView recyclerView) { super.onAttachedToRecyclerView(recyclerView); } @Override public int getItemCount() { return itemGetServerInfo.size(); } }