Need to combine my category, subcategory, item in java for my android app

Question

I have an app and I don't need to show the subcategory rather than i want to show the items page directly in my app like when user click category it should open items page without show the subcategory and shows all data of that category. here is my category code

import static com.grocery.food.Activity.HomeActivity.homeActivity;


public class CategoryFragment extends Fragment implements CategoryAdp.RecyclerTouchListener, GetResult.MyListener {
    // TODO: Rename parameter arguments, choose names that match

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    @BindView(R.id.recycler_view)
    RecyclerView recyclerView;

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;
    CategoryAdp adapter;
    List<CatItem> categoryList;
    Unbinder unbinder;
    SessionManager sessionManager;
    User user;

    public CategoryFragment() {
        // Required empty public constructor
    }

    // TODO: Rename and change types and number of parameters
    public static CategoryFragment newInstance(String param1, String param2) {
        CategoryFragment fragment = new CategoryFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_category, container, false);
        unbinder = ButterKnife.bind(this, view);
        categoryList = new ArrayList<>();
        sessionManager = new SessionManager(getActivity());
        user = sessionManager.getUserDetails("");

//        categoryList = (List<CatItem>) getArguments().getSerializable("arraylist");
        ;

        recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 3));
        recyclerView.setItemAnimator(new DefaultItemAnimator());

        getCategory();
        return view;
    }

    @Override
    public void onClickItem(View v, int position) {
        homeActivity.ShowMenu();
        Bundle args = new Bundle();
        args.putInt("id", position);
        Fragment fragment = new SubCategoryFragment();
        fragment.setArguments(args);
        HomeActivity.getInstance().callFragment(fragment);
    }

    @Override
    public void onLongClickItem(View v, int position) {

    }

    private void getCategory() {
        HomeActivity.custPrograssbar.PrograssCreate(getActivity());
        JSONObject jsonObject = new JSONObject();
        try {
            jsonObject.put("uid", user.getId());
            JsonParser jsonParser = new JsonParser();
            Call<JsonObject> call = APIClient.getInterface().getCat((JsonObject) jsonParser.parse(jsonObject.toString()));
            GetResult getResult = new GetResult();
            getResult.setMyListener(this);
            getResult.callForLogin(call, "1");
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void callback(JsonObject result, String callNo) {
        try {


            HomeActivity.custPrograssbar.ClosePrograssBar();
            if (callNo.equalsIgnoreCase("1") && result.toString() != null) {
                Gson gson = new Gson();
                Category category = gson.fromJson(result.toString(), Category.class);
                categoryList = category.getData();
                adapter = new CategoryAdp(getActivity(), categoryList, this);
                recyclerView.setAdapter(adapter);
            }
        } catch (Exception e) {

        }
    }
}

now when user clicks the category it should show only itemlist:

package com.grocery.food.Fragment;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.grocery.food.Activity.HomeActivity;
import com.grocery.food.Adepter.SubCategoryAdp;
import com.grocery.food.Model.SubCategory;
import com.grocery.food.Model.SubcatItem;
import com.grocery.food.Model.User;
import com.grocery.food.R;
import com.grocery.food.Utils.SessionManager;
import com.grocery.food.retrofit.APIClient;
import com.grocery.food.retrofit.GetResult;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.Unbinder;
import retrofit2.Call;

import static com.grocery.food.Activity.HomeActivity.homeActivity;


public class SubCategoryFragment extends Fragment implements GetResult.MyListener, SubCategoryAdp.RecyclerTouchListener {
    // TODO: Rename parameter arguments, choose names that match

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    @BindView(R.id.recycler_view)
    RecyclerView recyclerView;

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;
    SubCategoryAdp adapter;
    List<SubcatItem> categoryList;
    Unbinder unbinder;
    SessionManager sessionManager;
    User user;
    int CID = 0;

    public SubCategoryFragment() {
        // Required empty public constructor
    }

    // TODO: Rename and change types and number of parameters
    public static SubCategoryFragment newInstance(String param1, String param2) {
        SubCategoryFragment fragment = new SubCategoryFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_subcategory, container, false);
        unbinder = ButterKnife.bind(this, view);
        Bundle b = getArguments();
        CID = b.getInt("id");

        categoryList = new ArrayList<>();
        sessionManager = new SessionManager(getActivity());
        user = sessionManager.getUserDetails("");


        recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 3));
        recyclerView.setItemAnimator(new DefaultItemAnimator());

        getSubCategory();
        return view;
    }

    @Override
    public void onClickItem(View v, int cid, int scid) {
        homeActivity.ShowMenu();
        Bundle args = new Bundle();
        args.putInt("cid", cid);
        args.putInt("scid", scid);
        Fragment fragment = new ItemListFragment();
        fragment.setArguments(args);
        HomeActivity.getInstance().callFragment(fragment);
    }

    @Override
    public void onLongClickItem(View v, int position) {

    }

    private void getSubCategory() {
        HomeActivity.custPrograssbar.PrograssCreate(getActivity());
        JSONObject jsonObject = new JSONObject();
        try {
            jsonObject.put("category_id", CID);
            JsonParser jsonParser = new JsonParser();
            Call<JsonObject> call = APIClient.getInterface().getSubcategory((JsonObject) jsonParser.parse(jsonObject.toString()));
            GetResult getResult = new GetResult();
            getResult.setMyListener(this);
            getResult.callForLogin(call, "1");
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void callback(JsonObject result, String callNo) {
        try {


            HomeActivity.custPrograssbar.ClosePrograssBar();
            if (callNo.equalsIgnoreCase("1") && result.toString() != null) {
                Gson gson = new Gson();
                SubCategory category = gson.fromJson(result.toString(), SubCategory.class);
                categoryList = category.getData();
                adapter = new SubCategoryAdp(getActivity(), categoryList, this);
                recyclerView.setAdapter(adapter);
            }
        } catch (Exception e) {

        }
    }
}

now here's my itelist code please have a look to it too..

package com.grocery.food.Activity;

import android.database.Cursor;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.bumptech.glide.Glide;
import com.grocery.food.DataBase.DatabaseHelper;
import com.grocery.food.DataBase.MyCart;
import com.grocery.food.Model.Price;
import com.grocery.food.Model.ProductItem;
import com.grocery.food.R;
import com.grocery.food.Utils.SessionManager;
import com.grocery.food.retrofit.APIClient;

import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

import static com.grocery.food.Fragment.ItemListFragment.itemListFragment;
import static com.grocery.food.Utils.SessionManager.CURRUNCY;

public class ItemDetailsActivity extends AppCompatActivity {


    ProductItem productItem;
    Price price;
    @BindView(R.id.imgP)
    ImageView imgP;
    @BindView(R.id.img_back)
    ImageView imgBack;
    @BindView(R.id.img_cart)
    ImageView imgCart;
    @BindView(R.id.txt_tcount)
    TextView txtTcount;
    @BindView(R.id.lvl_cart)
    RelativeLayout lvlCart;
    @BindView(R.id.txt_title)
    TextView txtTitle;
    @BindView(R.id.txt_desc)
    TextView txtDesc;
    @BindView(R.id.lvl_pricelist)
    LinearLayout lvlPricelist;
    @BindView(R.id.btn_addtocart)
    Button btnAddtocart;
    ArrayList<Price> priceslist;
    DatabaseHelper databaseHelper;
    SessionManager sessionManager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_item_details);
        ButterKnife.bind(this);
        sessionManager=new SessionManager(this);
        databaseHelper = new DatabaseHelper(ItemDetailsActivity.this);
        productItem = (ProductItem) getIntent().getParcelableExtra("MyClass");
        priceslist = getIntent().getParcelableArrayListExtra("MyList");
        if (productItem != null) {
            txtTitle.setText("" + productItem.getProductName());
            txtDesc.setText("" + productItem.getShortDesc());
            Glide.with(this).load(APIClient.Base_URL + "/" + productItem.getProductImage()).thumbnail(Glide.with(this).load(R.drawable.ezgifresize)).into(imgP);
            setJoinPlayrList(lvlPricelist, productItem, priceslist);
            updateItem();
        }
    }

    public void updateItem() {
        Cursor res = databaseHelper.getAllData();
        if (res.getCount() == 0) {
            txtTcount.setText("0");

        } else {
            txtTcount.setText("" + res.getCount());
        }
    }

    @OnClick({R.id.img_back, R.id.lvl_cart, R.id.btn_addtocart})
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.img_back:
                finish();
                break;
            case R.id.lvl_cart:
                fragment();
                break;
            case R.id.btn_addtocart:
                finish();
                break;
        }
    }

    private void setJoinPlayrList(LinearLayout lnrView, ProductItem datum, List<Price> priceList) {

        lnrView.removeAllViews();
        final int[] count = {0};
        DatabaseHelper helper = new DatabaseHelper(lnrView.getContext());
        if (priceList != null && priceList.size() > 0) {
            for (int i = 0; i < priceList.size(); i++) {
                LayoutInflater inflater = LayoutInflater.from(this);

                View view = inflater.inflate(R.layout.custome_prize, null);

                TextView txt_price = view.findViewById(R.id.txt_price);
                TextView txt_gram = view.findViewById(R.id.txt_gram);
                TextView txt_offer = view.findViewById(R.id.txt_offer);
                TextView txtcount = view.findViewById(R.id.txtcount);
                LinearLayout img_mins = view.findViewById(R.id.img_mins);
                LinearLayout img_plus = view.findViewById(R.id.img_plus);
                MyCart myCart = new MyCart();
                myCart.setPID(datum.getId());
                myCart.setImage(datum.getProductImage());
                myCart.setTitle(datum.getProductName());
                myCart.setWeight(priceList.get(i).getProductType());
                myCart.setCost(priceList.get(i).getProductPrice());
                myCart.setDiscount(datum.getmDiscount());
                int qrt = helper.getCard(myCart.getPID(), myCart.getCost());
                if (qrt != -1) {
                    count[0] = qrt;
                    txtcount.setText("" + count[0]);
                    txtcount.setVisibility(View.VISIBLE);
                } else {
                    txtcount.setVisibility(View.VISIBLE);
                    img_mins.setVisibility(View.VISIBLE);
                }
                img_mins.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {

                        count[0] = Integer.parseInt(txtcount.getText().toString());

                        count[0] = count[0] - 1;
                        if (count[0] <= 0) {
                            img_mins.setVisibility(View.VISIBLE);
                            txtcount.setText("0");
                            txtcount.setVisibility(View.VISIBLE);
                            helper.deleteRData(myCart.getPID(), myCart.getCost());
                        } else {
                            txtcount.setVisibility(View.VISIBLE);
                            txtcount.setText("" + count[0]);
                            myCart.setQty(String.valueOf(count[0]));
                            Log.e("INsert", "--> " + helper.insertData(myCart));
                        }
                        if (itemListFragment != null)
                            itemListFragment.updateItem();
                        updateItem();
                    }
                });

                img_plus.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        txtcount.setVisibility(View.VISIBLE);
                        img_mins.setVisibility(View.VISIBLE);
                        count[0] = Integer.parseInt(txtcount.getText().toString());

                        count[0] = count[0] + 1;
                        txtcount.setText("" + count[0]);
                        myCart.setQty(String.valueOf(count[0]));
                        Log.e("INsert", "--> " + helper.insertData(myCart));
                        if (itemListFragment != null)
                            itemListFragment.updateItem();
                        updateItem();
                    }
                });


                txt_gram.setText("" + priceList.get(i).getProductType());


                if (datum.getmDiscount() > 0) {
                    double  res = (Double.parseDouble(priceList.get(i).getProductPrice()) / 100.0f)* datum.getmDiscount();
                    res = Integer.parseInt(priceList.get(i).getProductPrice()) - res;
                    txt_offer.setText(sessionManager.getStringData(CURRUNCY)+ priceList.get(i).getProductPrice());
                    txt_offer.setPaintFlags(txt_offer.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
                    txt_price.setText(sessionManager.getStringData(CURRUNCY)  + res);
                } else {
                    txt_offer.setVisibility(View.GONE);
                    txt_price.setText(sessionManager.getStringData(CURRUNCY)  + priceList.get(i).getProductPrice());
                }
                lnrView.addView(view);
            }
        }
    }

    public void fragment() {
        SessionManager.ISCART = true;
        finish();

    }


}