Retrofit 2 Example: Parsing dynamic JSON responses

ApiAdapter.java

package com.youtube.sorcjc.proyectoprofesionales.io;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.logging.HttpLoggingInterceptor;
import com.youtube.sorcjc.proyectoprofesionales.io.deserializers.LoginDeserializer;
import com.youtube.sorcjc.proyectoprofesionales.io.responses.LoginResponse;

import retrofit.GsonConverterFactory;
import retrofit.Retrofit;

public class ApiAdapter {

    private static ApiService API_SERVICE;

    public static ApiService getApiService() {

        // Creating the interceptor, and setting the log level
        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);

        // Adding the interceptor to a client
        OkHttpClient httpClient = new OkHttpClient();
        httpClient.interceptors().add(logging);

        if (API_SERVICE == null) {
            Retrofit retrofit = new Retrofit.Builder()
                    .baseUrl("https://project.test.com/api/")
                    .addConverterFactory(buildGsonConverter())
                    .client(httpClient) // <-- using the log level
                    .build();
            API_SERVICE = retrofit.create(ApiService.class);
        }

        return API_SERVICE;
    }

    private static GsonConverterFactory buildGsonConverter() {
        GsonBuilder gsonBuilder = new GsonBuilder();

        // Adding custom deserializers
        gsonBuilder.registerTypeAdapter(LoginResponse.class, new LoginDeserializer());
        Gson myGson = gsonBuilder.create();

        return GsonConverterFactory.create(myGson);
    }

}

LoginDeserializer.java

package com.youtube.sorcjc.proyectoprofesionales.io.deserializers;

import android.util.Log;

import com.google.gson.Gson;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.youtube.sorcjc.proyectoprofesionales.domain.UserAuthenticated;
import com.youtube.sorcjc.proyectoprofesionales.io.responses.LoginResponse;

import java.lang.reflect.Type;

public class LoginDeserializer implements JsonDeserializer<LoginResponse> {

    @Override
    public LoginResponse deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
        Log.d("Test/Deserializer", "Using a custom deserializer for the Login request");

        Gson gson = new Gson();
        LoginResponse loginResponse = gson.fromJson(json, LoginResponse.class);

        if (loginResponse.getStatus() == 1) {
            // The full response as a json object
            final JsonObject jsonObject = json.getAsJsonObject();
          
            // The response attribute in the JSON received
            final JsonElement jsonElement = jsonObject.get("response");

            // The response will be parsed because the status was 1
            UserAuthenticated userAuthenticated = gson.fromJson(jsonElement, UserAuthenticated.class);
            loginResponse.setResponse(userAuthenticated);
        }

        return loginResponse;
    }
}