Can I convert the JSON to HashMap using GsonConverterFactory?

Question

I got this data using the Retrofit library:

[
  {
    "countryId": "1472",
    "countryName": "{"ar": "ألمانيا", "default": "Germany"}",
    "image": "a304035c3dcb42cd990bb69b2f03e31f.png"
  },
  {
    "countryId": "1473",
    "countryName": "{"ar": "إيطاليا", "default": "Italy"}",
    "image": "5b3ae479ada846e98309ed978c2707b5.png"
  },
  {
    "countryId": "1474",
    "countryName": "{"ar": "هولندا", "default": "Netherlands"}",
    "image": "d810f9ab22434b4da08b838e72add09d.png"
  },
  {
    "countryId": "1475",
    "countryName": "{"ar": "بولندا", "default": "Poland"}",
    "image": "d8c4de2a11ca45759089fec204af9659.png"
  },
  {
    "countryId": "1476",
    "countryName": "{"ar": "رومانيا", "default": "Romania"}",
    "image": "47efdea8456244a5b9aae7132fca7418.png"
  },
  {
    "countryId": "1477",
    "countryName": "{"ar": "روسيا", "default": "Russia"}",
    "image": "7163f60a1c494e1b9f782edd3ecabd31.png"
  },
  {
    "countryId": "1478",
    "countryName": "{"ar": "إسبانيا", "default": "Spain"}",
    "image": "52fe49f594074b078fd5d8c9625018ee.png"
  },
  {
    "countryId": "1479",
    "countryName": "{"ar": "اوكرانيا", "default": "Ukraine"}",
    "image": "28581f7e4f324d938e0b109f7ee9203e.png"
  },
  {
    "countryId": "1480",
    "countryName": "{"ar": "المملكة المتحدة", "default": "United Kingdom"}",
    "image": "e7a87ff0caa241559f6c2559cc8606c3.png"
  },
  {
    "countryId": "2147483647",
    "countryName": "{"ar": "فرنسا", "default": "France"}",
    "image": "3830917201c74fc9b6b4ed0ddfdd4866.png"
  }
]

This is the code that gets the data:

Retrofit retrofit = new Retrofit.Builder().baseUrl(Constants.baseURL).addConverterFactory(GsonConverterFactory.create()).build();
TestInterface testInterface = retrofit.create(TestInterface.class);
testInterface.getCountries().enqueue(new Callback < List < CountriesModel >> () {
    @Override
    public void onResponse(@NonNull Call < List < CountriesModel >> call, @NonNull Response < List < CountriesModel >> response) {
        if (response.body() == null)
            return;
        for (CountriesModel item: response.body()) {
            Chip chip = new Chip(requireActivity());
            chip.setText(item.getCountryName());
            fragmentSelectCountryBinding.fragmentSelectCountryChipGroup281.addView(chip);
        }
    }

    @Override
    public void onFailure(@NonNull Call < List < CountriesModel >> call, @NonNull Throwable t) {
        Log.w(Tag, "Failed - " + t.getMessage());
    }
});

TestInterface

public interface TestInterface {

    @GET("FetchCountries.php")
    Call<List<CountriesModel>> getCountries();

}

CountriesModel Class

public class CountriesModel {

    @SerializedName("countryId")
    private long countryId;

    @SerializedName("countryName")
    private String countryName;

    @SerializedName("image")
    private String image;

    public long getCountryId() {
        return countryId;
    }

    public String getCountryName() {
        return countryName;
    }

    public String getImage() {
        return image;
    }

}

The Columns In MySQL

The country name are shown in the chip like this {"ar": "ألمانيا", "default": "Germany"}, {"ar": "إيطاليا", "default": "Italy"}, {"ar": "هولندا", "default": "Netherlands"}, etc...

The JSON who inside the country name. Can I store it in HashMap and get the value depending on the key like below?

chip.setText(item.getCountryName().get("default"));

Can I do something like this using GsonConverterFactory?

---

This answer is close to what I want, but I want to do that in the same model without creating two models.

Answer 1

Maybe you can, but I am not sure if you should. Your problem seems to be that the country name is actually "inner" JSON. I guess it is actually escaped like below since otherwise it would not be parsable:

[
 {
    "countryId": "1476",
    "countryName": "{\"ar\": \"رومانيا\", \"default\": \"Romania\"}",
    "image": "47efdea8456244a5b9aae7132fca7418.png"
  }
]

It is possible just to create a class of its own for countryName and a custom deserializer to handle this "inner" JSON. See the below example (there isn’t any need for the static inner classes, but I did it for brevity):

@Getter @Setter
public class CountriesModel {
    private long countryId;

    // define representation for complex name
    @Getter @Setter
    public static class CountryName {

        // define a custom deserializer for "inner" JSON
        public static class CountryNameDeserializer
                implements JsonDeserializer<CountryName> {
            private final Gson gson = new Gson();
            @Override
            public CountryName deserialize(JsonElement json, Type typeOfT,
                                           JsonDeserializationContext context)
                    throws JsonParseException {

                // gets the field as string and parses it again as a CountryName object
                return gson.fromJson(json.getAsString(), CountryName.class);
            }
        }
        private String ar;

        // default is a reserved word
        @SerializedName("default")
        private String defaultName;
    }

    // Use the adapter
    @JsonAdapter(CountryNameDeserializer.class)
    private CountryName countryName;
    private String image;
}

Now it would be just like:

someCountriesModel.getCountryName().getDefaultName();