Retrofit2 클린코드 설계 (Call사용)

                                    1. 타입 안정성
2. 간편 설정
3. JSON 변환
4. 동기 비동기 요청가능

                                    dependencies {
    // Retrofit 의존성
    implementation(com.squareup.retrofit2:retrofit:{new_version})

    // Gson 컨버터를 사용하기 위한 의존성
    implementation(com.squareup.retrofit2:converter-gson:{new_version})

    // for req, res loggin & debugging
    implementation(com.squareup.okhttp3:logging-interceptor:(new_version)")
}

                                    package com.example.myapplication.di

@Module
@InstallIn(SingletonComponent::class)
object RetrofitModule {

    @Singleton
    @Provides
    fun provideRetrofit(): Retrofit {
        val httpLoggingInterceptor = HttpLoggingInterceptor().apply {
            level = HttpLoggingInterceptor.Level.BODY
        } // 디버깅, 로깅을 위한 설정

        val okHttpClient = OkHttpClient.Builder()
            .addInterceptor(httpLoggingInterceptor)
            .readTimeout(60, TimeUnit.SECONDS)
            .connectTimeout(60, TimeUnit.SECONDS)
            .build()

        return Retrofit.Builder()
            .baseUrl("http://localhost:8080")
            .addConverterFactory(GsonConverterFactory.create())
            .client(okHttpClient)
            .build() // server ip, port 설정, convertor 설정 등
    }
}

                                    ApiInterface : url & http method

repository(@inject ApiInterface) : 실제 retrofit 통신

ViewModel(@Inject repository) : 실제 repository 사용하여 view 전용 데이터 관리

View() {val viewModel: ViewModel} : 전용 ViewModel을 불러와 필요한 데이터 화면에 표시

                                    package com.example.myapplication.network

import com.example.myapplication.dto.BoardResponse
import retrofit2.Call
import retrofit2.http.Body
import retrofit2.http.GET
import javax.inject.Singleton

@Singleton
interface BoardApiInterface {
    @GET("/boards")
    fun getAll(): Call<List<BoardResponse>>

    @GET("/board")
    fun getById(@Body id: Long): Call<BoardResponse>

}

                                    package com.example.myapplication.repository

import com.example.myapplication.dto.BoardResponse
import com.example.myapplication.network.BoardApiInterface
import dagger.hilt.android.scopes.ActivityScoped
import retrofit2.Call
import javax.inject.Inject
import javax.inject.Singleton
import retrofit2.Callback
import retrofit2.Response

@ActivityScoped
@Singleton
class BoardRepository @Inject constructor(
    private val boardApiInterface: BoardApiInterface
){
    fun getAll(callback: (Result<List<BoardResponse>>) -> Unit) {
        boardApiInterface.getAll().enqueue(object : Callback<List<BoardResponse>> {
            override fun onResponse( // call 응답 성공처리: http 응답코드로 판단
                call: Call<List<BoardResponse>>,
                response: Response<List<BoardResponse>>
            ) {
                if (response.isSuccessful) {
                    val boardResponse = response.body()
                }
            }

            override fun onFailure(p0: Call<List<BoardResponse>>, p1: Throwable) {
                TODO("Not yet implemented")
            } // call 실패 처리 : http 응답 코드로 판단
        })
    }
}

                                    🤔 하지만, 저의 프로젝트는 응답 코드를 모두 200으로 응답하고, 오류는 클라이언트와 합의된
응답코드를 사용하고 있습니다. 이럴 때는 어떻게 해야 할까요?

                                    package com.example.myapplication.network

import com.example.myapplication.dto.BoardResponse
import retrofit2.Call
import retrofit2.http.Body
import retrofit2.http.GET
import javax.inject.Singleton

@Singleton
interface BoardApiInterface {
    @GET("/boards")
    fun getAll(): Call<List<BoardResponse>> // ErrorResponse도 받아야 한다.

    @GET("/board")
    fun getById(@Body id: Long): Call<BoardResponse>

}

                                    // dto 수정사항

package com.example.myapplication.dto

data class BoardResponse(
    val boardResult: BoardResult?,
    val errorResponse: ErrorResponse?
)

package com.example.myapplication.dto

data class BoardAllResponse(
    val boardResults: List<BoardResult>,
    val errorResponse: ErrorResponse?
)