如何在recyclerView中添加所有添加的项目？

Question

我如何将具有相同名称的所有项目计为一个项目。如果使用添加按钮向购物车中添加商品的时间更多，则我在购物车中具有相同名称的商品获得的时间更多。如果我再次添加相同的商品，我该如何编码数量会增加？

这是Cart.java

    private void loadListFood() {
        cart = new Database(this).getCarts();
        adapter = new CartAdapter(cart, this);
        adapter.notifyDataSetChanged();
        recyclerView.setAdapter(adapter);

        //Calculate total
        double total = 0;
        for (Order order:cart)
            total+=(Double.parseDouble(order.getPrice()))*(Integer.parseInt(order.getQuantity()));
        Locale locale = new Locale("de", "DE");
        NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);

        txtTotalPrice.setText(fmt.format(total));

    }

这是Food.java

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_food_detail);

        //Firebase
        database = FirebaseDatabase.getInstance();
        food = database.getReference("Food");

        //init view
        numberButton = (ElegantNumberButton)findViewById(R.id.number_button);
        btnCart =(FloatingActionButton) findViewById(R.id.btnCart);

        btnCart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                new Database(getBaseContext()).addToCart(new Order(
                        foodId,
                        currentFood.getName(),
                        numberButton.getNumber(),
                        currentFood.getPrice(),
                        currentFood.getDiscount()

                ));


                Toast.makeText(FoodDetail.this, "Hinzugefügt!", Toast.LENGTH_SHORT).show();
            }
        });

        food_description = (TextView)findViewById(R.id.food_description);
        food_name = (TextView)findViewById(R.id.food_name);
        food_price = (TextView)findViewById(R.id.food_price);
        food_image = (ImageView)findViewById(R.id.img_food);

        collapsingToolbarLayout = (CollapsingToolbarLayout)findViewById(R.id.collapsing);
        collapsingToolbarLayout.setExpandedTitleTextAppearance(R.style.ExpandedAppbar);
        collapsingToolbarLayout.setExpandedTitleTextAppearance(R.style.CollapseddAppbar);

        //Get Food Id from Intent
        if (getIntent() != null)
            foodId = getIntent().getStringExtra("foodId");
        if(!foodId.isEmpty())
        {
            if (Common.isConnectedToInternet(getBaseContext()))
                getDetailFood(foodId);
            else{
                Toast.makeText(FoodDetail.this, "Stellen Sie bitte sicher, das eine aktive Internetverbindung vorhanden ist, und versuchen Sie es erneut!", Toast.LENGTH_SHORT).show();
                return;
            }
        });
    }