如何在Android中使用Retrofit和Gson解析嵌套的JSON数据

{
  "user": {
    "id": 1,
    "name": "John Doe",
    "email": "john.doe@example.com",
    "address": {
      "street": "123 Main St",
      "city": "Anytown",
      "zipcode": "12345"
    }
  }
}

public class User {
    private int id;
    private String name;
    private String email;
    private Address address;

    // Getters and setters
}

public class Address {
    private String street;
    private String city;
    private String zipcode;

    // Getters and setters
}

import retrofit2.Call;
import retrofit2.http.GET;

public interface ApiService {
    @GET("user")
    Call<User> getUser();
}

import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public class ApiClient {
    private static final String BASE_URL = "https://your-api-url.com/";
    private static Retrofit retrofit = null;

    public static Retrofit getClient() {
        if (retrofit == null) {
            retrofit = new Retrofit.Builder()
                    .baseUrl(BASE_URL)
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();
        }
        return retrofit;
    }
}

ApiService apiService = ApiClient.getClient().create(ApiService.class);
Call<User> call = apiService.getUser();

call.enqueue(new Callback<User>() {
    @Override
    public void onResponse(Call<User> call, Response<User> response) {
        if (response.isSuccessful()) {
            User user = response.body();
            // 处理用户数据
        } else {
            // 处理错误情况
        }
    }

    @Override
    public void onFailure(Call<User> call, Throwable t) {
        // 处理网络请求失败的情况
    }
});

public class User {
    private int id;
    private String name;
    private String email;
    private Address address = new Address(); // 提供默认实例

    // Getters and setters
}