fix: 공지사항에서 고정글을 3개로 제한하도록 변경

src/main/java/run/attraction/api/v1/announcement/controller/AnnouncementController.java

@@ -3,6 +3,7 @@
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.validation.Valid;
+import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
@@ -82,12 +83,8 @@ public ApiResponse<Page<PostSummaryDTO>> getPosts(
 
     @GetMapping("/pinned")
     @Operation(summary = "고정된 모든 게시물 가져오기", description = "고정된 모든 게시물을 가져오는 로직입니다.")
-    public ApiResponse<Page<PostSummaryDTO>> getPinnedPosts(
-            @RequestParam(defaultValue = "0") int page,
-            @RequestParam(defaultValue = "10") int size
-    ) {
-        Pageable pageable = PageRequest.of(page, size);
-        final Page<PostSummaryDTO> posts = announcementService.findPinnedPosts(pageable);
+    public ApiResponse<List<PostSummaryDTO>> getPinnedPosts() {
+        final List<PostSummaryDTO> posts = announcementService.findPinnedPosts();
 
         return ApiResponse.from(HttpStatus.OK, "성공", posts);
     }

src/main/java/run/attraction/api/v1/announcement/repository/AnnouncementRepository.java

@@ -1,5 +1,6 @@
 package run.attraction.api.v1.announcement.repository;
 
+import java.util.List;
 import java.util.Optional;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
@@ -42,7 +43,7 @@ public interface AnnouncementRepository extends JpaRepository<Post, Long> {
             WHERE p.isPinned = true
             ORDER BY p.createdAt DESC 
             """)
-    Page<Post> findAllWithPinned(Pageable pageable);
+    List<Post> findAllWithPinned();
 
     @Query("""
             SELECT p
@@ -57,4 +58,11 @@ public interface AnnouncementRepository extends JpaRepository<Post, Long> {
             ORDER BY p.createdAt DESC
             """)
     Page<Post> findPostsBySearchQuery(Pageable pageable, String searchType, String searchQuery);
+
+    @Query("""
+            SELECT COUNT(p)
+            FROM Post p
+            WHERE p.isPinned = true
+            """)
+    int countPinnedPosts();
 }

src/main/java/run/attraction/api/v1/announcement/service/AnnouncementService.java

@@ -1,5 +1,6 @@
 package run.attraction.api.v1.announcement.service;
 
+import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
@@ -19,12 +20,17 @@
 @RequiredArgsConstructor
 public class AnnouncementService {
 
+    private static final int PINNED_LIMIT = 3;
+
     private final AnnouncementRepository announcementRepository;
 
     @Transactional
     public void createPost(final PostCreateRequestDTO request) {
-        PostCategory category = PostCategory.valueOf(request.postCategory().toUpperCase());
+        if (request.isPinned()) {
+            checkPinnedPostCount();
+        }
 
+        PostCategory category = PostCategory.valueOf(request.postCategory().toUpperCase());
         Post post = Post.builder()
                 .title(request.title())
                 .content(request.content())
@@ -35,6 +41,12 @@ public void createPost(final PostCreateRequestDTO request) {
         announcementRepository.save(post);
     }
 
+    private void checkPinnedPostCount() {
+        if (announcementRepository.countPinnedPosts() >= PINNED_LIMIT) {
+            throw new IllegalArgumentException("고정글은 " + PINNED_LIMIT + "개를 초과할 수 없습니다.");
+        }
+    }
+
     @Transactional(readOnly = true)
     public PostDTO findPostById(final Long postId) {
         final Post post = announcementRepository.findById(postId)
@@ -54,11 +66,16 @@ public void deletePostById(final Long postId) {
     }
 
     @Transactional
-    public void updatePostById(final Long postId, final UpdatePostRequestDTO post) {
+    public void updatePostById(final Long postId, final UpdatePostRequestDTO request) {
         final Post beforePost = announcementRepository.findById(postId)
                 .orElseThrow(() -> new IllegalArgumentException("존재하지 않는 게시물입니다."));
 
-        beforePost.update(post.title(), post.content(), PostCategory.findByName(post.postCategory()), post.isPinned());
+        if (request.isPinned()) {
+            checkPinnedPostCount();
+        }
+
+        beforePost.update(request.title(), request.content(), PostCategory.findByName(request.postCategory()),
+                request.isPinned());
         announcementRepository.save(beforePost);
     }
 
@@ -70,10 +87,10 @@ public Page<PostSummaryDTO> findPosts(Pageable pageable) {
     }
 
     @Transactional(readOnly = true)
-    public Page<PostSummaryDTO> findPinnedPosts(Pageable pageable) {
-        final Page<Post> posts = announcementRepository.findAllWithPinned(pageable);
+    public List<PostSummaryDTO> findPinnedPosts() {
+        final List<Post> posts = announcementRepository.findAllWithPinned();
 
-        return posts.map(PostSummaryDTO::new);
+        return posts.stream().map(PostSummaryDTO::new).toList();
     }
 
     @Transactional(readOnly = true)