升序和降序整数排序

Question

I have a POJO class which contents for sorting Integer where integer obtained from JSON. When i implement it, Integer cannot sort ascending or descending.

Example : JSON has many data, one data has one integer. when i call all data and click for sort ascending, then integer sort ascending. But i use code like this, cannot sort integer.

Code :

public class ModelNameProductUrutkan {
    @SerializedName("price_regular")
    private int price;

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    // Filter Descending Integer
    public static final Comparator<ModelNameProductUrutkan> sortByHighPrice = new Comparator<ModelNameProductUrutkan>() {
        @Override
        public int compare(ModelNameProductUrutkan o1, ModelNameProductUrutkan o2) {
            return o2.getPrice() - o1.getPrice();
        }
    };

    // Filter Ascending Integer
    public static final Comparator<ModelNameProductUrutkan> sortByLowPrice = new Comparator<ModelNameProductUrutkan>() {
        @Override
        public int compare(ModelNameProductUrutkan o1, ModelNameProductUrutkan o2) {
            return o1.getPrice() - o2.getPrice();
        }
    };

SortingInteger.java :

private List<ModelNameProductUrutkan> modelNameProductUrutkans;

...............

    filterHargaTerendah.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Call<JsonObject> getProduct = baseApiService.getDetailProductCategory(category_id, perPage, source_id);
            getProduct.enqueue(new Callback<JsonObject>() {
                @Override
                public void onResponse(Call<JsonObject> call, Response<JsonObject> response) {
                    if (!response.isSuccessful()) {
                        Log.e(TAG, "Response Error : " + response.code());
                    } else {
                        try {
                            JSONObject jsonObject = new JSONObject(response.body().toString());
                            JSONObject object = jsonObject.getJSONObject("data");
                            JSONArray jsonArray = object.getJSONArray("items");
                            modelNameProductUrutkans = new ArrayList<>();

                            for(int a = 0; a <= jsonArray.length(); a++) {
                                JSONObject objectData = jsonArray.getJSONObject(a);

                                ModelNameProductUrutkan modelNameProductUrutkan = new ModelNameProductUrutkan();
                                modelNameProductUrutkan.setPrice(objectData.getInt("price_regular"));
                                modelNameProductUrutkans.add(modelNameProductUrutkan);

                                Toast.makeText(getContext(), "Sort By Low Price : " + modelNameProductUrutkan.getPrice(), Toast.LENGTH_SHORT).show();
                            }

                            Collections.sort(modelNameProductUrutkans, ModelNameProductUrutkan.sortByLowPrice);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }

                @Override
                public void onFailure(Call<JsonObject> call, Throwable t) {
                    Log.e(TAG, "onFailure: " + t.getMessage());
                }
            });
        }
    });

Answer 1

更改为以下方式，它应该可以工作：

return Integer.compare(o1.getPrice(), o2.getPrice());