refactor(HotBoards): 인기 게시글 저장에 Redis를 사용하도록 변경

src/main/java/page/clab/api/domain/community/board/adapter/in/web/HotBoardsRetrievalController.java

@@ -2,7 +2,6 @@
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.validation.constraints.Min;
 import lombok.RequiredArgsConstructor;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -25,16 +24,13 @@ public class HotBoardsRetrievalController {
     private final RetrieveHotBoardsUseCase retrieveHotBoardsUseCase;
 
     @Operation(summary = "[G] 커뮤니티 인기 게시글 목록 조회", description = "ROLE_GUEST 이상의 권한이 필요함<br>" +
-            "반응(이모지), 댓글 수를 합친 결과가 높은 순으로 size만큼 조회 가능<br>" +
             "인기 게시글 선정 타입 설정 가능")
     @PreAuthorize("hasRole('GUEST')")
     @GetMapping("/hot")
     public ApiResponse<List<BoardListResponseDto>> retrieveHotBoards(
-            @Min(message = "min.board.size", value = 0)
-            @RequestParam(name = "size", defaultValue = "5") int size,
             @RequestParam(name = "type") HotBoardStrategyType type
     ) {
-        List<BoardListResponseDto> boards = retrieveHotBoardsUseCase.retrieveHotBoards(size, type);
+        List<BoardListResponseDto> boards = retrieveHotBoardsUseCase.retrieveHotBoards(type);
         return ApiResponse.success(boards);
     }
 }

src/main/java/page/clab/api/domain/community/board/adapter/out/persistence/RedisHotBoardPersistenceAdapter.java

@@ -0,0 +1,38 @@
+package page.clab.api.domain.community.board.adapter.out.persistence;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Component;
+import page.clab.api.domain.community.board.application.port.out.RegisterHotBoardPort;
+import page.clab.api.domain.community.board.application.port.out.RemoveHotBoardPort;
+import page.clab.api.domain.community.board.application.port.out.RetrieveHotBoardPort;
+
+import java.util.List;
+
+@Component
+@RequiredArgsConstructor
+public class RedisHotBoardPersistenceAdapter implements
+        RegisterHotBoardPort,
+        RetrieveHotBoardPort,
+        RemoveHotBoardPort {
+
+    private static final String HOT_BOARDS_KEY = "hotBoards";
+
+    private final RedisTemplate<String, String> redisTemplate;
+
+    @Override
+    public void save(String boardId) {
+        redisTemplate.opsForList().rightPush(HOT_BOARDS_KEY, boardId);
+    }
+
+    @Override
+    public List<String> findAll() {
+        List<String> hotBoards = redisTemplate.opsForList().range(HOT_BOARDS_KEY, 0, -1);
+        return (hotBoards != null) ? hotBoards : List.of();
+    }
+
+    @Override
+    public void clearHotBoard() {
+        redisTemplate.delete(HOT_BOARDS_KEY);
+    }
+}

src/main/java/page/clab/api/domain/community/board/application/port/in/RetrieveHotBoardsUseCase.java

@@ -6,5 +6,5 @@
 import java.util.List;
 
 public interface RetrieveHotBoardsUseCase {
-    List<BoardListResponseDto> retrieveHotBoards(int size, HotBoardStrategyType type);
+    List<BoardListResponseDto> retrieveHotBoards(HotBoardStrategyType type);
 }

src/main/java/page/clab/api/domain/community/board/application/port/out/RegisterHotBoardPort.java

@@ -0,0 +1,5 @@
+package page.clab.api.domain.community.board.application.port.out;
+
+public interface RegisterHotBoardPort {
+    void save(String boardId);
+}

src/main/java/page/clab/api/domain/community/board/application/port/out/RemoveHotBoardPort.java

@@ -0,0 +1,5 @@
+package page.clab.api.domain.community.board.application.port.out;
+
+public interface RemoveHotBoardPort {
+    void clearHotBoard();
+}

src/main/java/page/clab/api/domain/community/board/application/port/out/RetrieveHotBoardPort.java

@@ -0,0 +1,7 @@
+package page.clab.api.domain.community.board.application.port.out;
+
+import java.util.List;
+
+public interface RetrieveHotBoardPort {
+    List<String> findAll();
+}

src/main/java/page/clab/api/domain/community/board/application/service/DefaultHotBoardsRetrievalService.java → src/main/java/page/clab/api/domain/community/board/application/service/DefaultHotBoardService.java

@@ -2,12 +2,16 @@
 
 import com.drew.lang.annotations.NotNull;
 import lombok.RequiredArgsConstructor;
+import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import page.clab.api.domain.community.board.application.dto.mapper.BoardDtoMapper;
 import page.clab.api.domain.community.board.application.dto.response.BoardListResponseDto;
+import page.clab.api.domain.community.board.application.port.out.RegisterHotBoardPort;
+import page.clab.api.domain.community.board.application.port.out.RemoveHotBoardPort;
 import page.clab.api.domain.community.board.application.port.out.RetrieveBoardEmojiPort;
 import page.clab.api.domain.community.board.application.port.out.RetrieveBoardPort;
+import page.clab.api.domain.community.board.application.port.out.RetrieveHotBoardPort;
 import page.clab.api.domain.community.board.domain.Board;
 import page.clab.api.domain.memberManagement.member.application.dto.shared.MemberDetailedInfoDto;
 import page.clab.api.external.community.comment.application.port.ExternalRetrieveCommentUseCase;
@@ -22,41 +26,59 @@
 
 @Service("default")
 @RequiredArgsConstructor
-public class DefaultHotBoardsRetrievalService implements HotBoardsStrategy {
+public class DefaultHotBoardService implements HotBoardsStrategy {
 
     private final RetrieveBoardPort retrieveBoardPort;
+    private final RetrieveHotBoardPort retrieveHotBoardPort;
+    private final RegisterHotBoardPort registerHotBoardPort;
+    private final RemoveHotBoardPort removeHotBoardPort;
     private final RetrieveBoardEmojiPort retrieveBoardEmojiPort;
     private final ExternalRetrieveCommentUseCase externalRetrieveCommentUseCase;
     private final ExternalRetrieveMemberUseCase externalRetrieveMemberUseCase;
     private final BoardDtoMapper mapper;
 
     @Transactional
     @Override
-    public List<BoardListResponseDto> retrieveHotBoards(int size) {
-        List<Board> hotBoards = getHotBoards(size);
+    public List<BoardListResponseDto> retrieveHotBoards() {
+        List<String> hotBoardIds = retrieveHotBoardPort.findAll();
 
-        return hotBoards.stream()
+        return hotBoardIds.stream()
+                .map(hotBoardId -> retrieveBoardPort.getById(Long.parseLong(hotBoardId)))
                 .map(board -> mapToBoardListResponseDto(board, getMemberDetailedInfoByBoard(board)))
                 .toList();
     }
 
-    private List<Board> getHotBoards(int size) {
-        // 만약 게시글의 총 개수가 size보다 적다면 모든 게시글 반환
+    @Transactional
+    @Scheduled(cron = "0 0 0 * * MON") // 매주 월요일 00:00 실행
+    public void saveHotBoards() {
+        clearHotBoards(); // 저장된 지난 인기 게시글 초기화
+
+        List<String> hotBoardIds = getHotBoards().stream()
+                .map(Board::getId)
+                .map(String::valueOf)
+                .toList();
+
+        hotBoardIds.forEach(registerHotBoardPort::save);
+    }
+
+    private List<Board> getHotBoards() {
+        // 만약 게시글의 총 개수가 5개보다 적다면 모든 게시글 반환
         List<Board> allBoards = retrieveBoardPort.findAll();
-        if (allBoards.size() < size) {
+        if (allBoards.size() < 5) {
             return sortBoardsByReactionAndDateWithLimit(allBoards.size(), allBoards);
         }
 
-        List<Board> hotBoards = getHotBoardsForWeek(1, size);
+        List<Board> hotBoards = getHotBoardsForWeek(1, 5);
 
         int weeksAgo = 2;
         // 필요한 수량을 확보할 때까지 반복해서 이전 주로 이동하여 인기 게시글 보충
-        while (hotBoards.size() < size) {
-            List<Board> additionalBoards = getLatestHotBoardForWeek(weeksAgo++, size - hotBoards.size());
+        while (hotBoards.size() < 5) {
+            List<Board> additionalBoards = getLatestHotBoardForWeek(weeksAgo++, 5 - hotBoards.size());
             if (additionalBoards != null && !additionalBoards.isEmpty()) {
                 hotBoards.addAll(additionalBoards);
             }
         }
+
         return hotBoards;
     }
 
@@ -108,4 +130,8 @@ private BoardListResponseDto mapToBoardListResponseDto(Board board, MemberDetail
 
         return mapper.toListDto(board, memberInfo, commentCount);
     }
+
+    private void clearHotBoards() {
+        removeHotBoardPort.clearHotBoard();
+    }
 }

src/main/java/page/clab/api/domain/community/board/application/service/HotBoardsRetrievalService.java

@@ -16,8 +16,8 @@ public class HotBoardsRetrievalService implements RetrieveHotBoardsUseCase {
     private final Map<String, HotBoardsStrategy> strategies;
 
     @Override
-    public List<BoardListResponseDto> retrieveHotBoards(int size, HotBoardStrategyType type) {
+    public List<BoardListResponseDto> retrieveHotBoards(HotBoardStrategyType type) {
         HotBoardsStrategy hotBoardsStrategy = strategies.get(type.getKey());
-        return hotBoardsStrategy.retrieveHotBoards(size);
+        return hotBoardsStrategy.retrieveHotBoards();
     }
 }

src/main/java/page/clab/api/domain/community/board/application/service/HotBoardsStrategy.java

@@ -5,5 +5,5 @@
 import java.util.List;
 
 public interface HotBoardsStrategy {
-    List<BoardListResponseDto> retrieveHotBoards(int size);
+    List<BoardListResponseDto> retrieveHotBoards();
 }