[FEAT]: 게시글 검색 기능 추가 (#18)

* [Chore]: QueryDSL 의존성 추가

* [Chore]: QueryDSL 사용을 위한 QueryFactory 빈 추가

* [Chore]: 검색 타입 enum 추가 (제목, 제목+내용, 작성자)

* [Chore]: 검색 시 필요한 요청 DTO 추가

* [Feat]: 게시글 검색 기능 구현

* [Feat]: 응답 DTO 게시글 작성자 추가

* [Feat]: 검색 기능 구현에 따른 파라미터, 메서드 호출 수정

* [Test]: 목록 조회 테스트 수정 및 테스트 데이터 Fixture 클래스로 분리

Author: shihan00321

back/build.gradle.kts

@@ -1,3 +1,6 @@
+import org.gradle.kotlin.dsl.annotationProcessor
+import org.gradle.kotlin.dsl.testAnnotationProcessor
+
 plugins {
     java
     id("org.springframework.boot") version "3.5.5"
@@ -43,6 +46,14 @@ dependencies {
     testImplementation("org.springframework.boot:spring-boot-starter-test")
     testImplementation("org.springframework.security:spring-security-test")
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+
+
+    // QueryDSL
+    implementation("io.github.openfeign.querydsl:querydsl-jpa:7.0")
+    annotationProcessor("io.github.openfeign.querydsl:querydsl-apt:7.0:jpa")
+    annotationProcessor("jakarta.persistence:jakarta.persistence-api")
+    testAnnotationProcessor("io.github.openfeign.querydsl:querydsl-apt:7.0:jpa")
+    testAnnotationProcessor("jakarta.persistence:jakarta.persistence-api")
 }
 
 tasks.withType<Test> {

back/src/main/java/com/back/domain/post/controller/PostController.java

@@ -2,6 +2,7 @@
 
 import com.back.domain.post.dto.PostRequest;
 import com.back.domain.post.dto.PostResponse;
+import com.back.domain.post.dto.PostSearchCondition;
 import com.back.domain.post.service.PostService;
 import com.back.global.common.ApiResponse;
 import com.back.global.common.PageResponse;
@@ -36,8 +37,9 @@ public ApiResponse<PostResponse> createPost(
 
     // 게시글 목록 조회
     @GetMapping
-    public ApiResponse<PageResponse<PostResponse>> getPosts(Pageable pageable) {
-        Page<PostResponse> responses = postService.getPosts(pageable);
+    public ApiResponse<PageResponse<PostResponse>> getPosts(
+            @ModelAttribute PostSearchCondition condition, Pageable pageable) {
+        Page<PostResponse> responses = postService.getPosts(condition, pageable);
         return ApiResponse.success(PageResponse.of(responses), "성공적으로 조회되었습니다.", HttpStatus.OK);
     }
 

back/src/main/java/com/back/domain/post/dto/PostResponse.java

@@ -18,6 +18,7 @@ public record PostResponse(
         Long id,
         String title,
         String content,
+        String author,
         PostCategory category,
         boolean hide,
         int likeCount,

back/src/main/java/com/back/domain/post/dto/PostSearchCondition.java

@@ -0,0 +1,17 @@
+package com.back.domain.post.dto;
+
+import com.back.domain.post.enums.PostCategory;
+import com.back.domain.post.enums.SearchType;
+
+/**
+ * 검색 조건
+ * @param category (CHAT, SCENARIO, POLL)
+ * @param searchType (TITLE, TITLE_CONTENT, AUTHOR)
+ * @param keyword (검색어)
+ */
+public record PostSearchCondition(
+        PostCategory category,
+        SearchType searchType,
+        String keyword
+) {
+}

back/src/main/java/com/back/domain/post/enums/SearchType.java

@@ -0,0 +1,11 @@
+package com.back.domain.post.enums;
+
+/**
+ * 검색 타입
+ * TITLE - 제목
+ * TITLE_CONTENT - 제목 + 내용
+ * AUTHOR - 작성자
+ */
+public enum SearchType {
+    TITLE, TITLE_CONTENT, AUTHOR
+}

back/src/main/java/com/back/domain/post/mapper/PostMapper.java

@@ -26,6 +26,7 @@ public static PostResponse toResponse(Post post) {
                 post.getId(),
                 post.getTitle(),
                 post.getContent(),
+                post.getUser().getNickname(),
                 post.getCategory(),
                 post.isHide(),
                 post.getLikeCount(),

back/src/main/java/com/back/domain/post/repository/PostRepository.java

@@ -8,5 +8,5 @@
  * 게시글 엔티티에 대한 데이터베이스 접근을 담당하는 JpaRepository.
  */
 @Repository
-public interface PostRepository extends JpaRepository<Post, Long> {
+public interface PostRepository extends JpaRepository<Post, Long>, PostRepositoryCustom {
 }

back/src/main/java/com/back/domain/post/repository/PostRepositoryCustom.java

@@ -0,0 +1,10 @@
+package com.back.domain.post.repository;
+
+import com.back.domain.post.dto.PostSearchCondition;
+import com.back.domain.post.entity.Post;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+
+public interface PostRepositoryCustom {
+    Page<Post> searchPosts(PostSearchCondition postSearchCondition, Pageable pageable);
+}

back/src/main/java/com/back/domain/post/repository/PostRepositoryCustomImpl.java

@@ -0,0 +1,74 @@
+package com.back.domain.post.repository;
+
+import com.back.domain.post.dto.PostSearchCondition;
+import com.back.domain.post.entity.Post;
+import com.back.domain.post.enums.PostCategory;
+import com.back.domain.post.enums.SearchType;
+import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.jpa.impl.JPAQuery;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.support.PageableExecutionUtils;
+import org.springframework.stereotype.Repository;
+import org.springframework.util.StringUtils;
+
+import java.util.List;
+
+import static com.back.domain.post.entity.QPost.post;
+import static com.back.domain.user.entity.QUser.user;
+
+@RequiredArgsConstructor
+@Repository
+public class PostRepositoryCustomImpl implements PostRepositoryCustom {
+    private final JPAQueryFactory queryFactory;
+
+    @Override
+    public Page<Post> searchPosts(PostSearchCondition condition, Pageable pageable) {
+        List<Post> posts = queryFactory
+                .selectFrom(post)
+                .leftJoin(post.user, user).fetchJoin()
+                .where(getCategoryCondition(condition.category()),
+                        getSearchCondition(condition.keyword(), condition.searchType()))
+                .orderBy(post.createdDate.desc())
+                .offset(pageable.getOffset())
+                .limit(pageable.getPageSize())
+                .fetch();
+
+        JPAQuery<Long> count = queryFactory
+                .select(post.count())
+                .from(post)
+                .where(
+                        getCategoryCondition(condition.category()),
+                        getSearchCondition(condition.keyword(), condition.searchType())
+                );
+
+        return PageableExecutionUtils.getPage(posts, pageable, count::fetchOne);
+    }
+
+    /**
+     * 1차 필터링 (CHAT, SCENARIO, POLL)
+     * category 조건이 null이 아니면 필터링 조건 추가
+     */
+    private BooleanExpression getCategoryCondition(PostCategory category) {
+        return category != null ? post.category.eq(category) : null;
+    }
+
+    /**
+     * 2차 필터링 (TITLE, TITLE_CONTENT, AUTHOR)
+     * fixme 현재 like 기반 검색 - 성능 최적화를 위해 추후에 수정 예정
+     */
+    private BooleanExpression getSearchCondition(String searchKeyword, SearchType searchType) {
+        if (!StringUtils.hasText(searchKeyword) || searchType == null) {
+            return null;
+        }
+
+        return switch (searchType) {
+            case TITLE -> post.title.containsIgnoreCase(searchKeyword);
+            case TITLE_CONTENT -> post.title.containsIgnoreCase(searchKeyword)
+                    .or(post.content.containsIgnoreCase(searchKeyword));
+            case AUTHOR -> post.user.nickname.containsIgnoreCase(searchKeyword);
+        };
+    }
+}

back/src/main/java/com/back/domain/post/service/PostService.java

@@ -2,6 +2,7 @@
 
 import com.back.domain.post.dto.PostRequest;
 import com.back.domain.post.dto.PostResponse;
+import com.back.domain.post.dto.PostSearchCondition;
 import com.back.domain.post.entity.Post;
 import com.back.domain.post.mapper.PostMapper;
 import com.back.domain.post.repository.PostRepository;
@@ -48,8 +49,8 @@ public PostResponse getPost(Long postId) {
                 .orElseThrow(() -> new ApiException(ErrorCode.POST_NOT_FOUND));
     }
 
-    public Page<PostResponse> getPosts(Pageable pageable) {
-        return postRepository.findAll(pageable)
+    public Page<PostResponse> getPosts(PostSearchCondition condition, Pageable pageable) {
+        return postRepository.searchPosts(condition, pageable)
                 .map(PostMapper::toResponse);
     }