Java Retrofit 返回空值

Question

我正在使用 Retrofit 使用 java 创建简单的 Android 项目。 但是改造返回null。

我的JSON

[
{
"id": "1536",
"id_category": "7"
},
{
"id": "1550",
"id_category": "7"
}
]

Place.java

public class Place {
@SerializedName("id")
private int id;
@SerializedName("id_category")
private int id_category;

public int getId() { return id; }

public void setId(int id) { this.id = id; }

public int getId_category() { return id_category; }

public void setId_category(int id_kategori) { this.id_category = id_kategori; }
}

PlaceService.java

public interface PlaceService {

@FormUrlEncoded
@POST("places/get_location_by_id_category")
Call<List<Place>> getPlaceByIdCategory(
        @Field("id_category") int id_category
);
}

ApiHttpClient.java

public class ApiHttpClient {
private static Retrofit retrofit = null;

public static Retrofit getRetrofit(){
    if (retrofit==null) {
        retrofit = new Retrofit.Builder()
                .baseUrl("http://admin.tapaleuk.id/api/")
                .addConverterFactory(GsonConverterFactory.create())
                .build();
    }
    return retrofit;
}

public static PlaceService getPlaceService(){
    PlaceService placeService = getRetrofit().create(PlaceService.class);
    return placeService;
}

}

还有Activity中的代码 私人无效read_id_by_category（int id_category）{ progressBar.setVisibility(View.VISIBLE);

    Activity activity = getActivity();
    if (activity != null) {

        Call<List<Place>> locationList = ApiHttpClient.getPlaceService().getPlaceByIdCategory(id_category);

        locationList.enqueue(new Callback<List<Place>>() {
            @Override
            public void onResponse(Call<List<Place>> call, Response<List<Place>> response) {
                if (response.isSuccessful()) {
                    location_list = response.body();

                    total_location = location_list.size();

                    id_location_array = new int[total_location];
                    id_category_array = new int[total_location];

                    for (int i = 0; i < total_location; i++) {
                        id_location_array[i] = location_list.get(i).getId();
                        id_category_array[i] = location_list.get(i).getId_category();
                    }
                }
            }

            @Override
            public void onFailure(Call<List<Place>> call, Throwable t) {
                t.printStackTrace();
            }
        });
    }

    progressBar.setVisibility(View.GONE);
}

代码“total_location = location_list.size();”中的total_location为空

谢谢

Answer 1

[ { "id": "1536", "id_category": "7" } ]

将此json添加到任何Json Validator中，你会发现这个json是错误的。 Du 为空。