我正在使用共享首选项将数据从itemdetails类发送到ordersfragment。我成功地接收到数据，但只是最后一个项目，它正在覆盖购物车中的项目。如何用新值更新从itemdetails发送的首选项？
这是我的itemdetails类：

btn_AddToCart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                SharedPreferences sharedPreferences = getApplicationContext().getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE);
                Gson gson = new Gson();

                // send names
                ArrayList<String> namesList = new ArrayList<>();
                namesList.add(name);
                String namesJson = gson.toJson(namesList);
                sharedPreferences.edit().putString("names", namesJson).apply();

                // send prices
                ArrayList<String> pricesList = new ArrayList<>();
                pricesList.add(price);
                String pricesJson = gson.toJson(pricesList);
                sharedPreferences.edit().putString("prices", pricesJson).apply();

            }

        });

这是ordersfragment：

SharedPreferences sharedPreferences = context.getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE);
        Gson gson = new Gson();

        // get names
        ArrayList<String> namesList = new ArrayList<>();
        String namesJson = sharedPreferences.getString("names", null);
        String[] names = gson.fromJson(namesJson, String[].class);
        if (names != null) {
            namesList.clear();
            namesList.addAll(Arrays.asList(names));
        }

        // get prices
        ArrayList<String> pricesList = new ArrayList<>();
        String pricesJson = sharedPreferences.getString("prices", null);
        String[] prices = gson.fromJson(pricesJson, String[].class);
        if (prices != null) {
            pricesList.clear();
            pricesList.addAll(Arrays.asList(prices));
        }

        RecyclerView rvOrdered = view.findViewById(R.id.rv_ordered);
        rvOrdered.setLayoutManager(new LinearLayoutManager(context));
        rvOrdered.setHasFixedSize(true);

        //populate the orders list
        ArrayList<OrderedModel> orders = new ArrayList<>();

            for(int i = 0; i < namesList.size(); i++) {
                orders.add(new OrderedModel(namesList.get(i), pricesList.get(i)));
            }

        rvOrdered.setAdapter(new OrderedRecyclerViewAdapter(context, orders));

如何更新itemdetails中的列表并获取ordersfragment中的所有订单，而不是一个订单？我可以使用多个共享首选项吗？我想我必须先从片段中获取数据，然后再添加新的值？