✨ [Feat] 연관 레크레이션 목록 API구현 및 예외처리 추가

src/main/java/com/avab/avab/controller/RecreationController.java

@@ -30,7 +30,8 @@
 import com.avab.avab.dto.reqeust.RecreationRequestDTO.PostRecreationReviewDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.DescriptionDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.FavoriteDTO;
-import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewListDTO;
+import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewDTO;
+import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewPageDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.RecreationReviewCreatedDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.RecreationReviewPageDTO;
 import com.avab.avab.security.handler.annotation.AuthUser;
@@ -62,12 +63,12 @@ public class RecreationController {
     })
     @Parameter(name = "user", hidden = true)
     @GetMapping("/popular")
-    public BaseResponse<RecreationPreviewListDTO> getTop9RecreationsByWeeklyViewCount(
+    public BaseResponse<RecreationPreviewPageDTO> getTop9RecreationsByWeeklyViewCount(
             @AuthUser User user) {
         Page<Recreation> topRecreations = recreationService.getTop9RecreationsByWeeklyViewCount();
 
         return BaseResponse.onSuccess(
-                RecreationConverter.toRecreationPreviewListDTO(topRecreations, user));
+                RecreationConverter.toRecreationPreviewPageDTO(topRecreations, user));
     }
 
     @Operation(summary = "레크레이션 상세설명 조회 API", description = "레크레이션 상세설명을 조회합니다. _by 수기_")
@@ -85,7 +86,7 @@ public BaseResponse<DescriptionDTO> getRecreationDescription(
     @ApiResponses({@ApiResponse(responseCode = "COMMON200", description = "OK, 성공")})
     @Parameter(name = "user", hidden = true)
     @GetMapping("/search")
-    public BaseResponse<RecreationPreviewListDTO> searchRecreations(
+    public BaseResponse<RecreationPreviewPageDTO> searchRecreations(
             @AuthUser User user,
             @RequestParam(name = "searchKeyword", required = false) String searchKeyword,
             @RequestParam(name = "keyword", required = false) List<Keyword> keywords,
@@ -111,7 +112,7 @@ public BaseResponse<RecreationPreviewListDTO> searchRecreations(
                         page);
 
         return BaseResponse.onSuccess(
-                RecreationConverter.toRecreationPreviewListDTO(recreationPage, user));
+                RecreationConverter.toRecreationPreviewPageDTO(recreationPage, user));
     }
 
     @Operation(
@@ -160,4 +161,18 @@ public BaseResponse<RecreationReviewPageDTO> getRecreationReviews(
         return BaseResponse.onSuccess(
                 RecreationConverter.toRecreationReviewPageDTO(reviewPage, user));
     }
+
+    @Operation(summary = "연관 레크레이션 API", description = "연관 레크레이션 목록을 가져옵니다. _by 수기_")
+    @ApiResponses({@ApiResponse(responseCode = "COMMON200", description = "OK, 성공")})
+    @Parameter(name = "user", hidden = true)
+    @GetMapping("/{recreationId}/related")
+    public BaseResponse<List<RecreationPreviewDTO>> relatedRecreation(
+            @AuthUser User user,
+            @ExistRecreation @PathVariable(name = "recreationId") Long recreationId) {
+        List<Recreation> relatedRecreation =
+                recreationService.findRelatedRecreations(user, recreationId);
+
+        return BaseResponse.onSuccess(
+                RecreationConverter.toRecreationPreviewListDTO(relatedRecreation, user));
+    }
 }

src/main/java/com/avab/avab/controller/UserController.java

@@ -17,7 +17,7 @@
 import com.avab.avab.domain.Recreation;
 import com.avab.avab.domain.User;
 import com.avab.avab.dto.reqeust.UserRequestDTO.UpdateUserNameDTO;
-import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewListDTO;
+import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewPageDTO;
 import com.avab.avab.dto.response.UserResponseDTO.UserResponse;
 import com.avab.avab.security.handler.annotation.AuthUser;
 import com.avab.avab.service.UserService;
@@ -45,14 +45,14 @@ public class UserController {
     @ApiResponses({@ApiResponse(responseCode = "COMMON200", description = "OK, 성공")})
     @GetMapping("/me/favorites/recreations")
     @Parameter(name = "user", hidden = true)
-    public BaseResponse<RecreationPreviewListDTO> getFavoriteRecreations(
+    public BaseResponse<RecreationPreviewPageDTO> getFavoriteRecreations(
             @RequestParam(name = "page", required = false, defaultValue = "0") @ValidatePage
                     Integer page,
             @AuthUser User user) {
         Page<Recreation> recreationPage = userService.getFavoriteRecreations(user, page);
 
         return BaseResponse.onSuccess(
-                RecreationConverter.toRecreationPreviewListDTO(recreationPage, user));
+                RecreationConverter.toRecreationPreviewPageDTO(recreationPage, user));
     }
 
     @Operation(summary = "회원 정보 수정 API", description = "회원 닉네임을 수정합니다. 닉네임을 인자로 받습니다. _by 루아_")

src/main/java/com/avab/avab/converter/RecreationConverter.java

@@ -21,7 +21,7 @@
 import com.avab.avab.dto.response.RecreationResponseDTO.DescriptionDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.FavoriteDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewDTO;
-import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewListDTO;
+import com.avab.avab.dto.response.RecreationResponseDTO.RecreationPreviewPageDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.RecreationReviewCreatedDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.RecreationReviewDTO;
 import com.avab.avab.dto.response.RecreationResponseDTO.RecreationReviewDTO.AuthorDTO;
@@ -31,9 +31,9 @@
 
 public class RecreationConverter {
 
-    public static RecreationPreviewListDTO toRecreationPreviewListDTO(
+    public static RecreationPreviewPageDTO toRecreationPreviewPageDTO(
             Page<Recreation> recreationPage, User user) {
-        return RecreationPreviewListDTO.builder()
+        return RecreationPreviewPageDTO.builder()
                 .recreationList(
                         recreationPage.getContent().stream()
                                 .map(recreation -> toRecreationPreviewDTO(recreation, user))
@@ -183,4 +183,11 @@ public static RecreationReviewDTO toRecreationReviewDTO(RecreationReview review,
                                 : null)
                 .build();
     }
+
+    public static List<RecreationPreviewDTO> toRecreationPreviewListDTO(
+            List<Recreation> recreations, User user) {
+        return recreations.stream()
+                .map(recreation -> toRecreationPreviewDTO(recreation, user))
+                .toList();
+    }
 }

src/main/java/com/avab/avab/dto/response/RecreationResponseDTO.java

@@ -38,7 +38,7 @@ public static class RecreationPreviewDTO {
     @Getter
     @NoArgsConstructor(access = AccessLevel.PROTECTED)
     @AllArgsConstructor(access = AccessLevel.PROTECTED)
-    public static class RecreationPreviewListDTO {
+    public static class RecreationPreviewPageDTO {
 
         List<RecreationPreviewDTO> recreationList;
         Integer totalPages;

src/main/java/com/avab/avab/repository/RecreationCustomRepository.java

@@ -24,4 +24,11 @@ Page<Recreation> searchRecreations(
             List<Gender> genders,
             List<Age> ages,
             Pageable page);
+
+    List<Recreation> findRelatedRecreations(
+            Long recreationId,
+            List<Keyword> keyword,
+            List<Purpose> purpose,
+            Integer maxParticipants,
+            List<Age> age);
 }

src/main/java/com/avab/avab/repository/RecreationCustomRepositoryImpl.java

@@ -2,20 +2,29 @@
 
 import static com.avab.avab.domain.QRecreation.recreation;
 
+import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
+import java.util.stream.Collectors;
 
+import org.apache.commons.lang3.tuple.Pair;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Repository;
 
+import com.avab.avab.apiPayload.code.status.ErrorStatus;
+import com.avab.avab.apiPayload.exception.RecreationException;
 import com.avab.avab.domain.QRecreation;
+import com.avab.avab.domain.QRecreationAge;
 import com.avab.avab.domain.Recreation;
 import com.avab.avab.domain.enums.Age;
 import com.avab.avab.domain.enums.Gender;
 import com.avab.avab.domain.enums.Keyword;
 import com.avab.avab.domain.enums.Place;
 import com.avab.avab.domain.enums.Purpose;
+import com.avab.avab.domain.mapping.QRecreationRecreationKeyword;
+import com.avab.avab.domain.mapping.QRecreationRecreationPurpose;
 import com.querydsl.core.types.dsl.BooleanExpression;
 import com.querydsl.jpa.impl.JPAQueryFactory;
 
@@ -107,4 +116,94 @@ private BooleanExpression inGender(List<Gender> genders) {
     private BooleanExpression inAge(List<Age> ages) {
         return ages != null ? recreation.recreationAgeList.any().age.in(ages) : null;
     }
+
+    @Override
+    public List<Recreation> findRelatedRecreations(
+            Long recreationId,
+            List<Keyword> keyword,
+            List<Purpose> purpose,
+            Integer maxParticipants,
+            List<Age> age) {
+        QRecreation recreation = QRecreation.recreation;
+        QRecreationRecreationPurpose recreationPurpose =
+                QRecreationRecreationPurpose.recreationRecreationPurpose;
+        QRecreationRecreationKeyword recreationKeyword =
+                QRecreationRecreationKeyword.recreationRecreationKeyword;
+        QRecreationAge recreationAge = QRecreationAge.recreationAge;
+        List<Pair<Recreation, Double>> recreationList = new ArrayList<>();
+
+        // 다른 Recreation id
+        List<Long> otherRecreationIds =
+                queryFactory
+                        .select(recreation.id)
+                        .from(recreation)
+                        .where(recreation.id.ne(recreationId))
+                        .fetch();
+
+        // 다른 레크레이션들과 비교
+        for (Long otherRecreationId : otherRecreationIds) {
+            Recreation otherRecreation =
+                    queryFactory
+                            .selectFrom(recreation)
+                            .where(recreation.id.eq(otherRecreationId))
+                            .fetchOne();
+            if (otherRecreation == null)
+                throw new RecreationException(ErrorStatus.RECREATION_NOT_FOUND);
+
+            // 겹치는 목적 체크
+            List<Purpose> purposesForComparison =
+                    queryFactory
+                            .select(recreationPurpose.purpose.purpose)
+                            .from(recreationPurpose)
+                            .where(recreationPurpose.recreation.id.eq(otherRecreationId))
+                            .fetch();
+
+            long purposeMatchSize =
+                    purposesForComparison.stream().filter(purpose::contains).count();
+
+            // 겹치는 키워드 체크
+            List<Keyword> keywordsForComparison =
+                    queryFactory
+                            .select(recreationKeyword.keyword.keyword)
+                            .from(recreationKeyword)
+                            .where(recreationKeyword.recreation.id.eq(otherRecreationId))
+                            .fetch();
+
+            long keywordMatchSize =
+                    keyword.stream().filter(keywordsForComparison::contains).count();
+
+            // 인원 기준 max인원과 다른 레크레이션의 min인원 차이확인
+            int participantsMatch =
+                    otherRecreation.getMinParticipants() != null
+                                    && maxParticipants > otherRecreation.getMinParticipants()
+                            ? maxParticipants - otherRecreation.getMinParticipants()
+                            : 0;
+
+            // 연령대 겹치는 개수 확인
+            List<Age> ageForComparison =
+                    queryFactory
+                            .select(recreationAge.age)
+                            .from(recreationAge)
+                            .where(recreationAge.recreation.id.eq(otherRecreationId))
+                            .fetch();
+
+            long ageMatchList = ageForComparison.stream().filter(age::contains).count();
+
+            // List에 추가
+            recreationList.add(
+                    Pair.of(
+                            otherRecreation,
+                            purposeMatchSize * 0.4
+                                    + keywordMatchSize * 0.3
+                                    + ageMatchList * 0.2
+                                    + participantsMatch * 0.10));
+        }
+
+        // 가중치별 내림차순 정렬
+        recreationList.sort(
+                Comparator.comparingDouble(Pair<Recreation, Double>::getRight).reversed());
+
+        // 최대 가중치를 가지는 2개의 레크레이션 리턴
+        return recreationList.stream().map(Pair::getLeft).limit(2).collect(Collectors.toList());
+    }
 }

src/main/java/com/avab/avab/security/SecurityConfig.java

@@ -37,6 +37,7 @@ public class SecurityConfig {
         "/api/recreations/popular",
         "/api/recreations/search",
         "/api/recreations/{recreationId}",
+        "/api/recreations/{recreationId}/related",
         "/api/recreations/popular",
         "/api/auth/login/kakao",
         "/api/auth/refresh"

src/main/java/com/avab/avab/service/RecreationService.java

@@ -37,4 +37,6 @@ Page<Recreation> searchRecreations(
     RecreationReview createReview(User user, Long recreationId, PostRecreationReviewDTO request);
 
     Page<RecreationReview> getRecreationReviews(Long recreationId, Integer page);
+
+    List<Recreation> findRelatedRecreations(User user, Long recreationId);
 }

src/main/java/com/avab/avab/service/impl/RecreationServiceImpl.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
@@ -12,6 +13,9 @@
 import com.avab.avab.apiPayload.exception.RecreationException;
 import com.avab.avab.converter.RecreationConverter;
 import com.avab.avab.domain.Recreation;
+import com.avab.avab.domain.RecreationAge;
+import com.avab.avab.domain.RecreationKeyword;
+import com.avab.avab.domain.RecreationPurpose;
 import com.avab.avab.domain.RecreationReview;
 import com.avab.avab.domain.User;
 import com.avab.avab.domain.enums.Age;
@@ -20,6 +24,8 @@
 import com.avab.avab.domain.enums.Place;
 import com.avab.avab.domain.enums.Purpose;
 import com.avab.avab.domain.mapping.RecreationFavorite;
+import com.avab.avab.domain.mapping.RecreationRecreationKeyword;
+import com.avab.avab.domain.mapping.RecreationRecreationPurpose;
 import com.avab.avab.dto.reqeust.RecreationRequestDTO.PostRecreationReviewDTO;
 import com.avab.avab.redis.service.RecreationViewCountService;
 import com.avab.avab.repository.RecreationFavoriteRepository;
@@ -47,7 +53,11 @@ public Page<Recreation> getTop9RecreationsByWeeklyViewCount() {
 
     @Transactional
     public Recreation getRecreationDescription(Long recreationId) {
-        Recreation recreation = recreationRepository.findById(recreationId).get();
+        Recreation recreation =
+                recreationRepository
+                        .findById(recreationId)
+                        .orElseThrow(
+                                () -> new RecreationException(ErrorStatus.RECREATION_NOT_FOUND));
 
         recreationViewCountService.incrementViewCount(recreation.getId());
 
@@ -151,4 +161,27 @@ private Boolean isAtLeastOneConditionNotNull(
                 || gender != null
                 || age != null;
     }
+
+    public List<Recreation> findRelatedRecreations(User user, Long recreationId) {
+        Recreation recreation =
+                recreationRepository
+                        .findById(recreationId)
+                        .orElseThrow(
+                                () -> new RecreationException(ErrorStatus.RECREATION_NOT_FOUND));
+
+        return recreationRepository.findRelatedRecreations(
+                recreationId,
+                recreation.getRecreationRecreationKeywordList().stream()
+                        .map(RecreationRecreationKeyword::getKeyword)
+                        .map(RecreationKeyword::getKeyword)
+                        .collect(Collectors.toList()),
+                recreation.getRecreationRecreationPurposeList().stream()
+                        .map(RecreationRecreationPurpose::getPurpose)
+                        .map(RecreationPurpose::getPurpose)
+                        .collect(Collectors.toList()),
+                recreation.getMaxParticipants(),
+                recreation.getRecreationAgeList().stream()
+                        .map(RecreationAge::getAge)
+                        .collect(Collectors.toList()));
+    }
 }