Home API에서 api 마다 languageCode를 별도로 받던 것을 LangContext를 사용하도록 리팩토링

- Interceptor에서 Accept-Language 헤더를 파싱
- 요청 단위 LangContext에 언어 정보 저장
- 서비스 및 예외 처리 계층에서 언어 컨텍스트 주입
- enum 및 when 기반 언어 정책을 한 곳으로 통합

src/main/kotlin/kr/co/vividnext/sodalive/api/home/HomeController.kt

@@ -17,7 +17,6 @@ class HomeController(private val service: HomeService) {
     @GetMapping
     fun fetchData(
         @RequestParam timezone: String,
-        @RequestParam(required = false) languageCode: String? = null,
         @RequestParam("isAdultContentVisible", required = false) isAdultContentVisible: Boolean? = null,
         @RequestParam("contentType", required = false) contentType: ContentType? = null,
         @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
@@ -25,7 +24,6 @@ class HomeController(private val service: HomeService) {
         ApiResponse.ok(
             service.fetchData(
                 timezone = timezone,
-                languageCode = languageCode,
                 isAdultContentVisible = isAdultContentVisible ?: true,
                 contentType = contentType ?: ContentType.ALL,
                 member
@@ -36,7 +34,6 @@ class HomeController(private val service: HomeService) {
     @GetMapping("/latest-content")
     fun getLatestContentByTheme(
         @RequestParam("theme") theme: String,
-        @RequestParam(required = false) languageCode: String? = null,
         @RequestParam("isAdultContentVisible", required = false) isAdultContentVisible: Boolean? = null,
         @RequestParam("contentType", required = false) contentType: ContentType? = null,
         @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
@@ -44,7 +41,6 @@ class HomeController(private val service: HomeService) {
         ApiResponse.ok(
             service.getLatestContentByTheme(
                 theme = theme,
-                languageCode = languageCode,
                 isAdultContentVisible = isAdultContentVisible ?: true,
                 contentType = contentType ?: ContentType.ALL,
                 member
@@ -74,15 +70,13 @@ class HomeController(private val service: HomeService) {
     fun getRecommendContents(
         @RequestParam("isAdultContentVisible", required = false) isAdultContentVisible: Boolean? = null,
         @RequestParam("contentType", required = false) contentType: ContentType? = null,
-        @RequestParam(required = false) languageCode: String? = null,
         @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
     ) = run {
         ApiResponse.ok(
             service.getRecommendContentList(
                 isAdultContentVisible = isAdultContentVisible ?: true,
                 contentType = contentType ?: ContentType.ALL,
-                member = member,
+                member = member
-                languageCode = languageCode
             )
         )
     }

src/main/kotlin/kr/co/vividnext/sodalive/api/home/HomeService.kt

@@ -1,6 +1,7 @@
 package kr.co.vividnext.sodalive.api.home
 
 import kr.co.vividnext.sodalive.audition.AuditionService
+import kr.co.vividnext.sodalive.chat.character.dto.Character
 import kr.co.vividnext.sodalive.chat.character.service.ChatCharacterService
 import kr.co.vividnext.sodalive.chat.character.translate.AiCharacterTranslationRepository
 import kr.co.vividnext.sodalive.content.AudioContentMainItem
@@ -16,6 +17,7 @@ import kr.co.vividnext.sodalive.content.translation.ContentTranslationRepository
 import kr.co.vividnext.sodalive.creator.admin.content.series.SeriesPublishedDaysOfWeek
 import kr.co.vividnext.sodalive.event.GetEventResponse
 import kr.co.vividnext.sodalive.explorer.ExplorerQueryRepository
+import kr.co.vividnext.sodalive.i18n.LangContext
 import kr.co.vividnext.sodalive.live.room.LiveRoomService
 import kr.co.vividnext.sodalive.live.room.LiveRoomStatus
 import kr.co.vividnext.sodalive.member.Member
@@ -52,6 +54,8 @@ class HomeService(
     private val contentTranslationRepository: ContentTranslationRepository,
     private val aiCharacterTranslationRepository: AiCharacterTranslationRepository,
 
+    private val langContext: LangContext,
+
     @Value("\${cloud.aws.cloud-front.host}")
     private val imageHost: String
 ) {
@@ -62,7 +66,6 @@ class HomeService(
 
     fun fetchData(
         timezone: String,
-        languageCode: String?,
         isAdultContentVisible: Boolean,
         contentType: ContentType,
         member: Member?
@@ -117,36 +120,7 @@ class HomeService(
             }
         }
 
-        /**
+        val translatedLatestContentList = getTranslatedContentList(contentList = latestContentList)
-         * latestContentList 번역 데이터 조회
-         *
-         * languageCode != null
-         * contentTranslationRepository를 이용해 번역 콘텐츠를 조회한다. - contentId, locale
-         *
-         * 한 번에 조회하고 contentId를 매핑하여 latestContentList의 title을 번역 데이터로 변경한다
-         */
-        val translatedLatestContentList = if (!languageCode.isNullOrBlank()) {
-            val contentIds = latestContentList.map { it.contentId }
-
-            if (contentIds.isNotEmpty()) {
-                val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
-                    .associateBy { it.contentId }
-
-                latestContentList.map { item ->
-                    val translatedTitle = translations[item.contentId]?.renderedPayload?.title
-                    if (translatedTitle.isNullOrBlank()) {
-                        item
-                    } else {
-                        item.copy(title = translatedTitle)
-                    }
-                }
-            } else {
-                latestContentList
-            }
-        } else {
-            latestContentList
-        }
 
         val eventBannerList = GetEventResponse(
             totalCount = 0,
@@ -175,39 +149,7 @@ class HomeService(
         )
 
         // 인기 캐릭터 조회
-        val popularCharacters = characterService.getPopularCharacters()
+        val translatedPopularCharacters = getTranslatedAiCharacterList(aiCharacterList = characterService.getPopularCharacters())
-
-        /**
-         * popularCharacters 캐릭터 이름 번역 데이터 조회
-         *
-         * languageCode != null
-         * aiCharacterTranslationRepository 이용해 번역 콘텐츠를 조회한다. - characterId, locale
-         *
-         * 한 번에 조회하고 characterId 매핑하여 popularCharacters의 캐릭터 이름을 번역 데이터로 변경한다
-         */
-        val translatedPopularCharacters = if (!languageCode.isNullOrBlank()) {
-            val characterIds = popularCharacters.map { it.characterId }
-
-            if (characterIds.isNotEmpty()) {
-                val translations = aiCharacterTranslationRepository
-                    .findByCharacterIdInAndLocale(characterIds = characterIds, locale = languageCode)
-                    .associateBy { it.characterId }
-
-                popularCharacters.map { character ->
-                    val translatedName = translations[character.characterId]?.renderedPayload?.name
-                    val translatedDesc = translations[character.characterId]?.renderedPayload?.description
-                    if (translatedName.isNullOrBlank() || translatedDesc.isNullOrBlank()) {
-                        character
-                    } else {
-                        character.copy(name = translatedName, description = translatedDesc)
-                    }
-                }
-            } else {
-                popularCharacters
-            }
-        } else {
-            popularCharacters
-        }
 
         val currentDateTime = LocalDateTime.now()
         val startDate = currentDateTime
@@ -228,20 +170,10 @@ class HomeService(
             sort = ContentRankingSortType.REVENUE
         )
 
-        /**
+        val contentRankingContentIds = contentRanking.map { it.contentId }
-         * contentRanking 번역 데이터 조회
+        val translatedContentRanking = if (contentRankingContentIds.isNotEmpty()) {
-         *
-         * languageCode != null
-         * contentTranslationRepository를 이용해 번역 콘텐츠를 조회한다. - contentId, locale
-         *
-         * 한 번에 조회하고 contentId를 매핑하여 contentRanking title을 번역 데이터로 변경한다
-         */
-        val translatedContentRanking = if (!languageCode.isNullOrBlank()) {
-            val contentIds = contentRanking.map { it.contentId }
-
-            if (contentIds.isNotEmpty()) {
             val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
+                .findByContentIdInAndLocale(contentIds = contentRankingContentIds, locale = langContext.lang.code)
                 .associateBy { it.contentId }
 
             contentRanking.map { item ->
@@ -255,9 +187,6 @@ class HomeService(
         } else {
             contentRanking
         }
-        } else {
-            contentRanking
-        }
 
         val recommendChannelList = recommendChannelService.getRecommendChannel(
             memberId = memberId,
@@ -273,15 +202,14 @@ class HomeService(
          *
          * 한 번에 조회하고 contentId를 매핑하여 recommendChannelList의 콘텐츠 title을 번역 데이터로 변경한다
          */
-        val translatedRecommendChannelList = if (!languageCode.isNullOrBlank()) {
+        val channelContentIds = recommendChannelList
-            val contentIds = recommendChannelList
             .flatMap { it.contentList }
             .map { it.contentId }
             .distinct()
 
-            if (contentIds.isNotEmpty()) {
+        val translatedRecommendChannelList = if (channelContentIds.isNotEmpty()) {
             val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
+                .findByContentIdInAndLocale(contentIds = channelContentIds, locale = langContext.lang.code)
                 .associateBy { it.contentId }
 
             recommendChannelList.map { channel ->
@@ -299,9 +227,6 @@ class HomeService(
         } else {
             recommendChannelList
         }
-        } else {
-            recommendChannelList
-        }
 
         val freeContentList = contentService.getLatestContentByTheme(
             theme = contentThemeService.getActiveThemeOfContent(
@@ -321,36 +246,7 @@ class HomeService(
             }
         }
 
-        /**
+        val translatedFreeContentList = getTranslatedContentList(contentList = freeContentList)
-         * freeContentList 번역 데이터 조회
-         *
-         * languageCode != null
-         * contentTranslationRepository를 이용해 번역 콘텐츠를 조회한다. - contentId, locale
-         *
-         * 한 번에 조회하고 contentId를 매핑하여 freeContentList title을 번역 데이터로 변경한다
-         */
-        val translatedFreeContentList = if (!languageCode.isNullOrBlank()) {
-            val contentIds = freeContentList.map { it.contentId }
-
-            if (contentIds.isNotEmpty()) {
-                val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
-                    .associateBy { it.contentId }
-
-                freeContentList.map { item ->
-                    val translatedTitle = translations[item.contentId]?.renderedPayload?.title
-                    if (translatedTitle.isNullOrBlank()) {
-                        item
-                    } else {
-                        item.copy(title = translatedTitle)
-                    }
-                }
-            } else {
-                freeContentList
-            }
-        } else {
-            freeContentList
-        }
 
         // 포인트 사용가능 콘텐츠 리스트 - 랜덤으로 가져오기 (DB에서 isPointAvailable 조건 적용)
         val pointAvailableContentList = contentService.getLatestContentByTheme(
@@ -368,36 +264,7 @@ class HomeService(
             }
         }
 
-        /**
+        val translatedPointAvailableContentList = getTranslatedContentList(contentList = pointAvailableContentList)
-         * pointAvailableContentList 번역 데이터 조회
-         *
-         * languageCode != null
-         * contentTranslationRepository를 이용해 번역 콘텐츠를 조회한다. - contentId, locale
-         *
-         * 한 번에 조회하고 contentId를 매핑하여 pointAvailableContentList title을 번역 데이터로 변경한다
-         */
-        val translatedPointAvailableContentList = if (!languageCode.isNullOrBlank()) {
-            val contentIds = pointAvailableContentList.map { it.contentId }
-
-            if (contentIds.isNotEmpty()) {
-                val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
-                    .associateBy { it.contentId }
-
-                pointAvailableContentList.map { item ->
-                    val translatedTitle = translations[item.contentId]?.renderedPayload?.title
-                    if (translatedTitle.isNullOrBlank()) {
-                        item
-                    } else {
-                        item.copy(title = translatedTitle)
-                    }
-                }
-            } else {
-                pointAvailableContentList
-            }
-        } else {
-            pointAvailableContentList
-        }
 
         val curationList = curationService.getContentCurationList(
             tabId = 3L, // 기존에 사용하던 단편 탭의 큐레이션을 사용
@@ -424,8 +291,7 @@ class HomeService(
             recommendContentList = getRecommendContentList(
                 isAdultContentVisible = isAdultContentVisible,
                 contentType = contentType,
-                member = member,
+                member = member
-                languageCode = languageCode
             ),
             curationList = curationList
         )
@@ -433,7 +299,6 @@ class HomeService(
 
     fun getLatestContentByTheme(
         theme: String,
-        languageCode: String?,
         isAdultContentVisible: Boolean,
         contentType: ContentType,
         member: Member?
@@ -464,38 +329,7 @@ class HomeService(
             }
         }
 
-        /**
+        return getTranslatedContentList(contentList = contentList)
-         * contentList 번역 데이터 조회
-         *
-         * languageCode != null
-         * contentTranslationRepository를 이용해 번역 콘텐츠를 조회한다. - contentId, locale
-         *
-         * 한 번에 조회하고 contentId를 매핑하여 contentList title을 번역 데이터로 변경한다
-         */
-        val translatedContentList = if (!languageCode.isNullOrBlank()) {
-            val contentIds = contentList.map { it.contentId }
-
-            if (contentIds.isNotEmpty()) {
-                val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
-                    .associateBy { it.contentId }
-
-                contentList.map { item ->
-                    val translatedTitle = translations[item.contentId]?.renderedPayload?.title
-                    if (translatedTitle.isNullOrBlank()) {
-                        item
-                    } else {
-                        item.copy(title = translatedTitle)
-                    }
-                }
-            } else {
-                contentList
-            }
-        } else {
-            contentList
-        }
-
-        return translatedContentList
     }
 
     fun getDayOfWeekSeriesList(
@@ -571,8 +405,7 @@ class HomeService(
     fun getRecommendContentList(
         isAdultContentVisible: Boolean,
         contentType: ContentType,
-        member: Member?,
+        member: Member?
-        languageCode: String? = null
     ): List<AudioContentMainItem> {
         val memberId = member?.id
         val isAdult = member?.auth != null && isAdultContentVisible
@@ -607,23 +440,33 @@ class HomeService(
             }
         }
 
-        /**
+        return getTranslatedContentList(contentList = result)
-         * 추천 콘텐츠 번역 데이터 조회
+    }
-         *
-         * languageCode != null
-         * contentTranslationRepository를 이용해 번역 콘텐츠를 조회한다. - contentId, locale
-         *
-         * 한 번에 조회하고 contentId를 매핑하여 result의 title을 번역 데이터로 변경한다
-         */
-        val translatedResult = if (!languageCode.isNullOrBlank()) {
-            val contentIds = result.map { it.contentId }
 
-            if (contentIds.isNotEmpty()) {
+    /**
+     * 콘텐츠 리스트의 제목을 현재 언어(locale)에 맞춰 일괄 번역한다.
+     *
+     * 처리 절차:
+     * - 입력된 콘텐츠들의 contentId 집합을 만들고, 요청 언어 코드(langContext.lang.code)로
+     *   contentTranslationRepository에서 번역 데이터를 한 번에 조회한다.
+     * - 각 항목에 대해 번역된 제목이 존재하고 비어있지 않으면 title만 번역 값으로 교체한다.
+     * - 번역이 없거나 공백이면 원본 항목을 그대로 반환한다.
+     *
+     * 성능:
+     * - N건의 항목을 1회의 조회로 해결하기 위해 IN 쿼리를 사용한다.
+     *
+     * @param contentList 번역 대상 AudioContentMainItem 목록
+     * @return 제목이 가능한 항목은 번역된 목록(불변 사본), 그 외는 원본 항목 유지
+     */
+    private fun getTranslatedContentList(contentList: List<AudioContentMainItem>): List<AudioContentMainItem> {
+        val contentIds = contentList.map { it.contentId }
+
+        return if (contentIds.isNotEmpty()) {
             val translations = contentTranslationRepository
-                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
+                .findByContentIdInAndLocale(contentIds = contentIds, locale = langContext.lang.code)
                 .associateBy { it.contentId }
 
-                result.map { item ->
+            contentList.map { item ->
                 val translatedTitle = translations[item.contentId]?.renderedPayload?.title
                 if (translatedTitle.isNullOrBlank()) {
                     item
@@ -632,12 +475,41 @@ class HomeService(
                 }
             }
         } else {
-                result
+            contentList
         }
-        } else {
-            result
     }
 
-        return translatedResult
+    /**
+     * AI 캐릭터 리스트의 이름/설명을 현재 언어(locale)에 맞춰 일괄 번역한다.
+     *
+     * 처리 절차:
+     * - characterId 목록을 추출하고, 요청 언어 코드로 aiCharacterTranslationRepository에서
+     *   번역 데이터를 한 번에 조회한다.
+     * - 각 캐릭터에 대해 name과 description 모두 번역 값이 존재하고 비어있지 않을 때에만
+     *   해당 필드를 교체한다. 둘 중 하나라도 없으면 원본 캐릭터를 그대로 유지한다.
+     *
+     * @param aiCharacterList 번역 대상 캐릭터 목록
+     * @return 가능한 경우 name/description이 번역된 캐릭터 목록, 그 외는 원본 유지
+     */
+    private fun getTranslatedAiCharacterList(aiCharacterList: List<Character>): List<Character> {
+        val characterIds = aiCharacterList.map { it.characterId }
+
+        return if (characterIds.isNotEmpty()) {
+            val translations = aiCharacterTranslationRepository
+                .findByCharacterIdInAndLocale(characterIds = characterIds, locale = langContext.lang.code)
+                .associateBy { it.characterId }
+
+            aiCharacterList.map { character ->
+                val translatedName = translations[character.characterId]?.renderedPayload?.name
+                val translatedDesc = translations[character.characterId]?.renderedPayload?.description
+                if (translatedName.isNullOrBlank() || translatedDesc.isNullOrBlank()) {
+                    character
+                } else {
+                    character.copy(name = translatedName, description = translatedDesc)
+                }
+            }
+        } else {
+            aiCharacterList
+        }
     }
 }

src/main/kotlin/kr/co/vividnext/sodalive/configs/WebConfig.kt

@@ -1,11 +1,19 @@
 package kr.co.vividnext.sodalive.configs
 
+import kr.co.vividnext.sodalive.i18n.LangInterceptor
 import org.springframework.context.annotation.Configuration
 import org.springframework.web.servlet.config.annotation.CorsRegistry
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer
 
 @Configuration
-class WebConfig : WebMvcConfigurer {
+class WebConfig(
+    private val langInterceptor: LangInterceptor
+) : WebMvcConfigurer {
+    override fun addInterceptors(registry: InterceptorRegistry) {
+        registry.addInterceptor(langInterceptor).addPathPatterns("/**")
+    }
+
     override fun addCorsMappings(registry: CorsRegistry) {
         registry.addMapping("/**")
             .allowedOrigins(

src/main/kotlin/kr/co/vividnext/sodalive/explorer/ExplorerController.kt

@@ -52,6 +52,7 @@ class ExplorerController(private val service: ExplorerService) {
     fun getCreatorProfile(
         @PathVariable("id") creatorId: Long,
         @RequestParam timezone: String,
+        @RequestParam("languageCode", required = false) languageCode: String? = null,
         @RequestParam("isAdultContentVisible", required = false) isAdultContentVisible: Boolean? = null,
         @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
     ) = run {
@@ -60,6 +61,7 @@ class ExplorerController(private val service: ExplorerService) {
             service.getCreatorProfile(
                 creatorId = creatorId,
                 timezone = timezone,
+                languageCode = languageCode,
                 isAdultContentVisible = isAdultContentVisible ?: true,
                 member = member
             )

src/main/kotlin/kr/co/vividnext/sodalive/explorer/ExplorerService.kt

@@ -7,6 +7,7 @@ import kr.co.vividnext.sodalive.content.LanguageDetectEvent
 import kr.co.vividnext.sodalive.content.LanguageDetectTargetType
 import kr.co.vividnext.sodalive.content.SortType
 import kr.co.vividnext.sodalive.content.series.ContentSeriesService
+import kr.co.vividnext.sodalive.content.translation.ContentTranslationRepository
 import kr.co.vividnext.sodalive.explorer.follower.GetFollowerListResponse
 import kr.co.vividnext.sodalive.explorer.follower.GetFollowerListResponseItem
 import kr.co.vividnext.sodalive.explorer.profile.ChannelNotice
@@ -46,6 +47,7 @@ class ExplorerService(
     private val seriesService: ContentSeriesService,
 
     private val applicationEventPublisher: ApplicationEventPublisher,
+    private val contentTranslationRepository: ContentTranslationRepository,
 
     @Value("\${cloud.aws.cloud-front.host}")
     private val cloudFrontHost: String
@@ -170,6 +172,7 @@ class ExplorerService(
     fun getCreatorProfile(
         creatorId: Long,
         timezone: String,
+        languageCode: String?,
         isAdultContentVisible: Boolean,
         member: Member
     ): GetCreatorProfileResponse {
@@ -233,6 +236,29 @@ class ExplorerService(
             listOf()
         }
 
+        val translatedContentList = if (!languageCode.isNullOrBlank() && contentList.isNotEmpty()) {
+            val contentIds = contentList.map { it.contentId }
+
+            if (contentIds.isNotEmpty()) {
+                val translations = contentTranslationRepository
+                    .findByContentIdInAndLocale(contentIds = contentIds, locale = languageCode)
+                    .associateBy { it.contentId }
+
+                contentList.map { item ->
+                    val translatedTitle = translations[item.contentId]?.renderedPayload?.title
+                    if (translatedTitle.isNullOrBlank()) {
+                        item
+                    } else {
+                        item.copy(title = translatedTitle)
+                    }
+                }
+            } else {
+                contentList
+            }
+        } else {
+            contentList
+        }
+
         // 크리에이터의 최신 오디오 콘텐츠 1개
         val latestContent = if (isCreator) {
             audioContentService.getLatestCreatorAudioContent(creatorId, member, isAdultContentVisible)
@@ -333,7 +359,7 @@ class ExplorerService(
             userDonationRanking = memberDonationRanking,
             similarCreatorList = similarCreatorList,
             liveRoomList = liveRoomList,
-            contentList = contentList,
+            contentList = translatedContentList,
             latestContent = latestContent,
             totalContentCount = totalContentCount,
             ownedContentCount = ownedContentCount,

src/main/kotlin/kr/co/vividnext/sodalive/i18n/Lang.kt

@@ -0,0 +1,22 @@
+package kr.co.vividnext.sodalive.i18n
+
+import java.util.Locale
+
+enum class Lang(val code: String, val locale: Locale) {
+    KO("ko", Locale.KOREAN),
+    EN("en", Locale.ENGLISH),
+    JA("ja", Locale.JAPANESE);
+
+    companion object {
+        fun fromAcceptLanguage(header: String?): Lang {
+            if (header.isNullOrBlank()) return KO
+            val two = header.trim().lowercase().take(2) // 앱은 2자리만 보내지만 안전하게 처리
+            return when (two) {
+                "ko" -> KO
+                "en" -> EN
+                "ja" -> JA
+                else -> KO
+            }
+        }
+    }
+}

src/main/kotlin/kr/co/vividnext/sodalive/i18n/LangContext.kt

@@ -0,0 +1,15 @@
+package kr.co.vividnext.sodalive.i18n
+
+import org.springframework.stereotype.Component
+import org.springframework.web.context.annotation.RequestScope
+
+@Component
+@RequestScope
+class LangContext {
+    var lang: Lang = Lang.KO
+        internal set
+
+    fun setLang(lang: Lang) {
+        this.lang = lang
+    }
+}

src/main/kotlin/kr/co/vividnext/sodalive/i18n/LangInterceptor.kt

@@ -0,0 +1,21 @@
+package kr.co.vividnext.sodalive.i18n
+
+import org.springframework.stereotype.Component
+import org.springframework.web.servlet.HandlerInterceptor
+import javax.servlet.http.HttpServletRequest
+import javax.servlet.http.HttpServletResponse
+
+@Component
+class LangInterceptor(
+    private val langContext: LangContext
+) : HandlerInterceptor {
+    override fun preHandle(
+        request: HttpServletRequest,
+        response: HttpServletResponse,
+        handler: Any
+    ): Boolean {
+        val acceptLanguage = request.getHeader("Accept-Language")
+        langContext.setLang(Lang.fromAcceptLanguage(acceptLanguage))
+        return true
+    }
+}