[feat] Spring Cache(Caffeine) 도입 — 화이트리스트 기반 Strict + after-commit 이벤트 무효화

build.gradle

@@ -105,6 +105,10 @@ dependencies {
 	testImplementation 'com.squareup.okhttp3:mockwebserver:4.12.0'
 
 	implementation 'org.springframework.retry:spring-retry'
+
+    // Cache
+    implementation 'org.springframework.boot:spring-boot-starter-cache'
+    implementation 'com.github.ben-manes.caffeine:caffeine'
 }
 
 tasks.named('test') {

src/main/java/kr/co/pinup/cache/AppCacheProps.java

@@ -0,0 +1,14 @@
+package kr.co.pinup.cache;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import java.util.Map;
+
+@ConfigurationProperties(prefix ="spring.cache.app")
+public record AppCacheProps(
+        Defaults defaults,
+        Map<String, Spec> caches
+) {
+    public record Defaults(Long maximumSize, Integer ttlSec) {}
+    public record Spec(Long maximumSize, Integer ttlSec) {}
+}

src/main/java/kr/co/pinup/cache/CacheNames.java

@@ -0,0 +1,6 @@
+package kr.co.pinup.cache;
+
+public interface CacheNames {
+    String POST_DETAIL = "post:detail";
+    String POST_IMAGES = "post:images";
+}

src/main/java/kr/co/pinup/cache/listener/PostCacheInvalidationListener.java

@@ -0,0 +1,45 @@
+package kr.co.pinup.cache.listener;
+
+import kr.co.pinup.cache.CacheNames;
+import kr.co.pinup.posts.event.PostCacheEvent;
+import lombok.RequiredArgsConstructor;
+import org.springframework.cache.Cache;
+import org.springframework.cache.CacheManager;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+@Component
+@RequiredArgsConstructor
+public class PostCacheInvalidationListener {
+
+    private final CacheManager cacheManager;
+
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
+    public void on(PostCacheEvent event) {
+        switch (event.kind()) {
+            case UPDATED -> {
+                if (event.detailChanged()) {
+                    evictIfPresent(CacheNames.POST_DETAIL, event.postId());
+                }
+                if (event.imagesChanged()) {
+                    evictIfPresent(CacheNames.POST_IMAGES, event.postId());
+                }
+            }
+            case DISABLED -> {
+                evictIfPresent(CacheNames.POST_DETAIL, event.postId());
+            }
+            case DELETED -> {
+                evictIfPresent(CacheNames.POST_DETAIL, event.postId());
+                evictIfPresent(CacheNames.POST_IMAGES, event.postId());
+            }
+        }
+    }
+
+    private void evictIfPresent(String cacheName, Object key) {
+        Cache cache = cacheManager.getCache(cacheName);
+        if (cache != null) {
+            cache.evict(key);
+        }
+    }
+}

src/main/java/kr/co/pinup/config/CacheConfig.java

@@ -0,0 +1,48 @@
+package kr.co.pinup.config;
+
+import com.github.benmanes.caffeine.cache.Caffeine;
+import kr.co.pinup.cache.AppCacheProps;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.caffeine.CaffeineCache;
+import org.springframework.cache.caffeine.CaffeineCacheManager;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableConfigurationProperties(AppCacheProps.class)
+public class CacheConfig {
+
+    @Bean
+    public CacheManager cacheManager(AppCacheProps props) {
+
+        return new CaffeineCacheManager() {
+            {
+                setAllowNullValues(false);
+                setCacheNames(props.caches().keySet());
+            }
+
+            @Override
+            protected CaffeineCache createCaffeineCache(String name) {
+                Caffeine<Object, Object> builder = Caffeine.newBuilder().recordStats();
+
+                var d = props.defaults();
+                var s = props.caches().get(name);
+
+                Long maxSize = (s != null && s.maximumSize() != null)
+                        ? s.maximumSize()
+                        : (d != null ? d.maximumSize() : null);
+
+                Integer ttlSec = (s != null && s.ttlSec() != null)
+                        ? s.ttlSec()
+                        : (d != null ? d.ttlSec() : null);
+
+                if (maxSize != null) builder = builder.maximumSize(maxSize);
+                if (ttlSec != null) builder = builder.expireAfterWrite(java.time.Duration.ofSeconds(ttlSec));
+
+                return new CaffeineCache(name, builder.build(), false);
+            }
+
+        };
+    }
+}

src/main/java/kr/co/pinup/postImages/repository/PostImageRepository.java

@@ -12,6 +12,8 @@ public interface PostImageRepository extends JpaRepository<PostImage, Long> {
 
     List<PostImage> findByPostId(Long postId);
 
+    List<PostImage> findAllByPostIdOrderByIdAsc(Long postId);
+
     void deleteAllByPostId(Long postId);
 
     List<PostImage> findByPostIdAndS3UrlIn(Long id, List<String> images);

src/main/java/kr/co/pinup/postImages/service/PostImageService.java

@@ -1,31 +1,28 @@
 package kr.co.pinup.postImages.service;
 
-import kr.co.pinup.custom.s3.exception.ImageDeleteFailedException;
-import kr.co.pinup.postImages.model.dto.PostImageUploadRequest;
-import org.springframework.transaction.annotation.Propagation;
-import org.springframework.transaction.annotation.Transactional;
-import org.springframework.transaction.support.TransactionSynchronization;
-import org.springframework.transaction.support.TransactionSynchronizationManager;
-
+import kr.co.pinup.cache.CacheNames;
 import kr.co.pinup.custom.logging.AppLogger;
 import kr.co.pinup.custom.logging.model.dto.ErrorLog;
 import kr.co.pinup.custom.logging.model.dto.InfoLog;
 import kr.co.pinup.custom.logging.model.dto.WarnLog;
 import kr.co.pinup.custom.s3.S3Service;
-
 import kr.co.pinup.postImages.PostImage;
 import kr.co.pinup.postImages.exception.postimage.PostImageDeleteFailedException;
 import kr.co.pinup.postImages.exception.postimage.PostImageNotFoundException;
 import kr.co.pinup.postImages.exception.postimage.PostImageSaveFailedException;
 import kr.co.pinup.postImages.model.dto.CreatePostImageRequest;
 import kr.co.pinup.postImages.model.dto.PostImageResponse;
-
 import kr.co.pinup.postImages.model.dto.UpdatePostImageRequest;
 import kr.co.pinup.postImages.repository.PostImageRepository;
 import kr.co.pinup.posts.Post;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.cache.annotation.Cacheable;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 import org.springframework.web.multipart.MultipartFile;
 
 import java.util.List;
@@ -173,6 +170,11 @@ public void deleteS3QuietlyAfterCommit(List<String> imageUrls) {
         }
     }
 
+    @Cacheable(
+            value = CacheNames.POST_IMAGES,
+            key = "#p0",  // postId
+            sync = true
+    )
     @Transactional(readOnly = true)
     public List<PostImageResponse> findImagesByPostId(Long postId) {
         log.debug("이미지 목록 조회: postId={}", postId);

src/main/java/kr/co/pinup/posts/event/PostCacheEvent.java

@@ -0,0 +1,20 @@
+package kr.co.pinup.posts.event;
+
+public record PostCacheEvent(
+        Long postId,
+        Kind kind,
+        boolean detailChanged,   // UPDATED일 때만 의미
+        boolean imagesChanged    // UPDATED일 때만 의미
+) {
+    public enum Kind { UPDATED, DISABLED, DELETED }
+
+    public static PostCacheEvent updated(Long postId, boolean detailChanged, boolean imagesChanged) {
+        return new PostCacheEvent(postId, Kind.UPDATED, detailChanged, imagesChanged);
+    }
+    public static PostCacheEvent disabled(Long postId) {
+        return new PostCacheEvent(postId, Kind.DISABLED, false, false);
+    }
+    public static PostCacheEvent deleted(Long postId) {
+        return new PostCacheEvent(postId, Kind.DELETED, false, false);
+    }
+}

src/main/java/kr/co/pinup/posts/service/PostService.java

@@ -1,5 +1,6 @@
 package kr.co.pinup.posts.service;
 
+import kr.co.pinup.cache.CacheNames;
 import kr.co.pinup.custom.logging.AppLogger;
 import kr.co.pinup.custom.logging.model.dto.ErrorLog;
 import kr.co.pinup.custom.logging.model.dto.InfoLog;
@@ -10,10 +11,11 @@
 import kr.co.pinup.postImages.PostImage;
 import kr.co.pinup.postImages.exception.postimage.PostImageUpdateCountException;
 import kr.co.pinup.postImages.model.dto.CreatePostImageRequest;
-import kr.co.pinup.postImages.model.dto.PostImageResponse;
 import kr.co.pinup.postImages.model.dto.UpdatePostImageRequest;
+import kr.co.pinup.postImages.repository.PostImageRepository;
 import kr.co.pinup.postImages.service.PostImageService;
 import kr.co.pinup.posts.Post;
+import kr.co.pinup.posts.event.PostCacheEvent;
 import kr.co.pinup.posts.exception.post.PostDeleteFailedException;
 import kr.co.pinup.posts.exception.post.PostNotFoundException;
 import kr.co.pinup.posts.model.dto.CreatePostRequest;
@@ -25,6 +27,8 @@
 import kr.co.pinup.stores.repository.StoreRepository;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.multipart.MultipartFile;
@@ -43,7 +47,10 @@ public class PostService {
     private final PostImageService postImageService;
     private final MemberRepository memberRepository;
     private final StoreRepository storeRepository;
-    private final AppLogger appLogger;
+    private final PostImageRepository postImageRepository;
+    private final AppLogger appLogger ;
+    private final ApplicationEventPublisher events;
+
 
     private record ChangeFlags(boolean hasText, boolean hasUpload, boolean hasDelete) {
     }
@@ -111,6 +118,12 @@ public List<PostResponse> findByStoreIdWithCommentsAndLikes(Long storeId, boolea
 
     }
 
+    @Cacheable(
+            value = CacheNames.POST_DETAIL,
+            key = "#p0",
+            condition = "!#p1",
+            sync = true
+    )
     @Transactional(readOnly = true)
     public PostResponse getPostById(Long id, boolean isDeleted) {
         log.debug("게시글 단건 요청: postId={}, isDeleted={}", id, isDeleted);
@@ -133,6 +146,7 @@ public void deletePost(Long postId) {
         }
         try {
             postRepository.delete(post);
+            events.publishEvent(PostCacheEvent.deleted(postId));
             appLogger.info(new InfoLog("게시글 삭제 성공").setStatus("200").setTargetId(postId.toString()));
         } catch (Exception e) {
             appLogger.error(new ErrorLog("게시글 삭제 실패", e)
@@ -148,6 +162,7 @@ public void disablePost(Long postId) {
         post.disablePost(true);
         appLogger.info(new InfoLog("게시글 비활성화 처리").setStatus("200").setTargetId(postId.toString()));
         postRepository.save(post);
+        events.publishEvent(PostCacheEvent.disabled(postId));
     }
 
     public Post findByIdOrThrow(Long id) {
@@ -235,6 +250,8 @@ private  PostResponse updatePostTx(Long id,
             if (!actuallyDeleted.isEmpty()) {
                 postImageService.deleteS3QuietlyAfterCommit(actuallyDeleted);
             }
+            if (imagesChanged ) {
+                events.publishEvent(PostCacheEvent.updated(id, /*detailChanged*/ false, /*imagesChanged*/ true));            }
             return PostResponse.from(post);
         }
 
@@ -249,6 +266,10 @@ private  PostResponse updatePostTx(Long id,
             if (!actuallyDeleted.isEmpty()) {
                 postImageService.deleteS3QuietlyAfterCommit(actuallyDeleted);
             }
+            events.publishEvent(PostCacheEvent.updated(
+                    id,
+                    /* detailChanged */  (textChanged || thumbChanged),/* imagesChanged */  (imagesChanged || thumbChanged)
+            ));
         }
     }
 
@@ -277,7 +298,7 @@ private ImageMutationResult mutateImagesAndRefresh(
     private boolean refreshThumbnailIfNeeded(Post post, Long postId, boolean imagesChanged) {
         if (!imagesChanged) return false;
 
-        List<PostImageResponse> remaining = postImageService.findImagesByPostId(postId);
+        List<PostImage> remaining = postImageRepository.findAllByPostIdOrderByIdAsc(postId);
         if (remaining.size() < 2) throw new PostImageUpdateCountException();
 
         String current = post.getThumbnail();