android - How to implement Infinite Scrolling with RecyclerView?

Question

I have a recycler and inside of it there are cardviews where I fetch information from a REST service, I'm trying to implement an endless scroll, It's supposed that user will see 10 cardviews every time he scrolls down until there are no more cardviews to show, How can I achieve that?

I've seen a few examples but none of them really helped me about how to do it. I don't even know what I need to put in adapter.class or in my Fragment.class because I don't understand how to implement that, it would be great if someone could tell me the correct way to implement the infinite scroll in my code...

Thanks in advance.

MainAdapter.class

public class MainAdapter extends RecyclerView.Adapter<MainAdapter.ViewHolder> implements View.OnClickListener
{
    private ArrayList<Business> businessList;
    private Activity activity;
    private int layoutMolde,idb;

    public MainAdapter(Activity activity, ArrayList<Business> list, int layout) 
    {
        this.activity = activity;
        this.businessList = list;
        layoutMolde = layout;
    }

    @Override
    public MainAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 
    {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.main_row, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) 
    {
        holder.mTitle.setText(businessList.get(position).getBusiness_name());
        holder.number_rating.setText(businessList.get(position).getRating().toString());
        Glide.with(activity).load(businessList.get(position).getLogo_url_string()).into(holder.mImg);
    }

    @Override
    public int getItemCount() {
        return businessList.size();
    }

    @Override
    public void onClick(View v) 
    {

    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        public TextView mTitle;
        public ImageView mImg;
        public ImageView logo;
        public RatingBar main_rating;
        public TextView number_rating;

        public ViewHolder( View itemView) 
        {
            super(itemView);
            mTitle = (TextView) itemView.findViewById(R.id.nom_business_main);
            number_rating = (TextView) itemView.findViewById(R.id.number_rating);
            mImg = (ImageView) itemView.findViewById(R.id.img_main);
            main_rating=(RatingBar) itemView.findViewById(R.id.rating_main);
            main_rating.setRating((float)1);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v)
                {

                    Intent in = new Intent(v.getContext(), BusinessPremium.class);
                    int position = getAdapterPosition();
                    idb = businessList.get(position).getId();
                    in.putExtra("no", idb);
                    v.getContext().startActivity(in);
                }
            });
        }
    }
}

FeedsFragment.class

    public class FeedsFragment extends Fragment
    {

        private ArrayList<Business> arrayBusiness,arrayBasics;
        private Gson gson;

        private static final Type BUSINESS_TYPE = new TypeToken<ArrayList<Business>>() {}.getType();
        private RecyclerView.LayoutManager mLayoutManager;

        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
        {
            View android = inflater.inflate(R.layout.fragment_feeds, container, false);

            if (!internetConnectionCheck(FeedsFragment.this.getActivity())) 
            {
                Toast.makeText(getApplicationContext(), "Error de Conexión", Toast.LENGTH_LONG).show();
            }

            new RequestBase(getActivity()) {

                @Override
                public JsonObject onHttpOk(JsonObject response) throws JSONException {

                    JsonObject objeto, pagination_details = null, details, premium_img;
                    JsonArray data;

                    if (getActivity() == null)
                        return response;

                    if (response.get("pagination") == null) 
                    {
                        objeto = response;

                    } else {
                        objeto = response;
                        pagination_details = response.get("pagination").getAsJsonObject();
                        data = objeto.get("data").getAsJsonArray();
                        gson = new Gson();
                        arrayBusiness = gson.fromJson(data, BUSINESS_TYPE);
                        Log.d("size", String.valueOf(arrayBusiness.size()));
                        FeedsFragment.this.getActivity().runOnUiThread(new Runnable()
                        {
                            @Override
                            public void run() 
                            {

                                RecyclerView recycler = (RecyclerView) FeedsFragment.this.getActivity().findViewById(R.id.recycler_main);
                                MainAdapter adapter = new MainAdapter(getActivity(), arrayBusiness, R.layout.main_row);

                                recycler.setNestedScrollingEnabled(false);
                                mLayoutManager = new GridLayoutManager(FeedsFragment.this.getActivity(), 2);
                                recycler.setLayoutManager(mLayoutManager);
                                recycler.setAdapter(adapter);

                                GifTextView loading = (GifTextView)FeedsFragment.this.getActivity().findViewById(R.id.loading);
                                TextView loadingText = (TextView)FeedsFragment.this.getActivity().findViewById(R.id.loadingText);
                                loading.setVisibility(View.GONE);
                                loadingText.setVisibility(View.GONE);

                            }
                        });
                    }
                    if (pagination_details.isJsonNull()) {
                        Log.d("Paginacion", pagination_details.toString());
                    }
                    return objeto;
                }

                @Override
                public void onHttpCreate(JsonObject response) throws JSONException 
                {

                }

                @Override
                public void onHttpUnprocessableEntity(JsonObject response) throws JSONException 
                {
                    this.cancel(true);
                    final String error = response.get("errors").toString();
                    getActivity().runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(getActivity().getApplicationContext(), error, Toast.LENGTH_LONG).show();
                        }
                    });
                }
            }.execute("businesses/premiums", "GET");

            return android;
        }
}

Answer 1

you can refresh using SwipeRefreshLayout in android to refresh and in the on refresh override method call your api

note:put your API call request in a method and call that method inyour onRefresh method of SwipeRefreshLayout