[FEAT] 게시글 찜하기 기능 구현, Mypage 찜한 게시글 목록 조회 (#143)

* feat: 좋아요 Entity, Repository 추가

* feat: 게시글 좋아요 엔드포인트 추가, Service 로직 작성, Custom Repository 추가

* fix: memberServicae -> memberService 오타 수정

* feat: @repository 추가

* feat: Mypage 찜한 게시글 조회

* style: { 앞 공백 추가

* refactor: @repository 제거

* refactor: 안쓰는 함수 제거

* feat: 게시글 조회시 잘못된 정렬 방식에 대한 예외 처리

* feat: PostLike에 Optional 적용 및 찜 관리시 조회 순서 변경

* refactor: 찜 관리 기능 map, orElseGet사용하여 구현

src/main/java/econo/buddybridge/comment/repository/CommentRepository.java

@@ -2,8 +2,6 @@
 
 import econo.buddybridge.comment.entity.Comment;
 import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.stereotype.Repository;
 
-@Repository
 public interface CommentRepository extends JpaRepository<Comment, Long> {
 }

src/main/java/econo/buddybridge/post/controller/PostLikeController.java

@@ -0,0 +1,50 @@
+package econo.buddybridge.post.controller;
+
+import econo.buddybridge.post.dto.PostCustomPage;
+import econo.buddybridge.post.entity.PostType;
+import econo.buddybridge.post.service.PostLikeService;
+import econo.buddybridge.utils.api.ApiResponse;
+import econo.buddybridge.utils.api.ApiResponseGenerator;
+import econo.buddybridge.utils.session.SessionUtils;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.servlet.http.HttpServletRequest;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/posts/likes")
+@Tag(name = "게시글 좋아요 API", description = "게시글 좋아요 관련 API")
+public class PostLikeController {
+
+    private final PostLikeService postLikeService;
+
+    @Operation(summary = "찜한 게시글 관리", description = "찜한 게시글 관리 찜을(생성, 삭제)합니다.")
+    @PostMapping("/{post-id}")
+    public ApiResponse<ApiResponse.CustomBody<Boolean>> managePostLike(
+            @PathVariable(name = "post-id") Long postId,
+            HttpServletRequest request
+    ) {
+        Long memberId = SessionUtils.getMemberId(request);
+        Boolean isLike = postLikeService.managePostLike(memberId, postId);
+        return ApiResponseGenerator.success(isLike, HttpStatus.OK);
+    }
+
+
+    @Operation(summary = "찜한 게시글 목록 조회", description = "찜한 게시글 목록을 조회합니다.")
+    @GetMapping("/my-page")
+    public ApiResponse<ApiResponse.CustomBody<PostCustomPage>> getPostLikes(
+            @RequestParam("page") Integer page,
+            @RequestParam("size") Integer size,
+            @RequestParam(defaultValue = "desc", required = false) String sort,
+            @RequestParam(value = "post-type", required = false) PostType postType,
+            HttpServletRequest request
+    ) {
+        Long memberId = SessionUtils.getMemberId(request);
+        PostCustomPage posts = postLikeService.getPostsLikes(memberId, page, size, sort, postType);
+        return ApiResponseGenerator.success(posts, HttpStatus.OK);
+    }
+
+}

src/main/java/econo/buddybridge/post/entity/PostLike.java

@@ -0,0 +1,32 @@
+package econo.buddybridge.post.entity;
+
+import econo.buddybridge.member.entity.Member;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "POST_LIKE")
+public class PostLike {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "post_id")
+    private Post post;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "member_id")
+    private Member member;
+
+    public PostLike(Post post, Member member) {
+        this.post = post;
+        this.member = member;
+    }
+
+}

src/main/java/econo/buddybridge/post/exception/PostErrorCode.java

@@ -8,6 +8,7 @@ public enum PostErrorCode implements ErrorCode {
     POST_DELETE_NOT_ALLOWED("P002", HttpStatus.FORBIDDEN, "본인의 게시글만 삭제할 수 있습니다."),
     POST_UPDATE_NOT_ALLOWED("P003", HttpStatus.FORBIDDEN, "본인의 게시글만 수정할 수 있습니다."),
     POST_UNAUTHORIZED_ACCESS("P004", HttpStatus.BAD_REQUEST, "회원님이 작성한 게시글이 아닙니다."),
+    POST_INVALID_SORT_VALUE("P005", HttpStatus.BAD_REQUEST, "유효하지 않은 정렬 값입니다.(desc, asc중 하나를 넣어주세요)"),
     ;
 
     private final String code;
@@ -34,4 +35,5 @@ public HttpStatus getHttpStatus() {
     public String getMessage() {
         return message;
     }
+
 }

src/main/java/econo/buddybridge/post/exception/PostInvalidSortValueException.java

@@ -0,0 +1,12 @@
+package econo.buddybridge.post.exception;
+
+import econo.buddybridge.common.exception.BusinessException;
+
+public class PostInvalidSortValueException extends BusinessException {
+
+    public static BusinessException EXCEPTION = new PostInvalidSortValueException();
+
+    private PostInvalidSortValueException() {
+        super(PostErrorCode.POST_INVALID_SORT_VALUE);
+    }
+}

src/main/java/econo/buddybridge/post/repository/PostLikeRepository.java

@@ -0,0 +1,8 @@
+package econo.buddybridge.post.repository;
+
+import econo.buddybridge.post.entity.PostLike;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PostLikeRepository extends JpaRepository<PostLike, Long>, PostLikeRepositoryCustom {
+
+}

src/main/java/econo/buddybridge/post/repository/PostLikeRepositoryCustom.java

@@ -0,0 +1,14 @@
+package econo.buddybridge.post.repository;
+
+import econo.buddybridge.post.dto.PostCustomPage;
+import econo.buddybridge.post.entity.PostLike;
+import econo.buddybridge.post.entity.PostType;
+
+import java.util.Optional;
+
+public interface PostLikeRepositoryCustom {
+
+    Optional<PostLike> findByPostIdAndMemberId(Long postId, Long memberId);
+
+    PostCustomPage findPostsByLikes(Long memberId, Integer page, Integer size, String sort, PostType postType);
+}

src/main/java/econo/buddybridge/post/repository/PostLikeRepositoryCustomImpl.java

@@ -0,0 +1,70 @@
+package econo.buddybridge.post.repository;
+
+import com.querydsl.core.types.OrderSpecifier;
+import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import econo.buddybridge.post.dto.PostCustomPage;
+import econo.buddybridge.post.dto.PostResDto;
+import econo.buddybridge.post.entity.PostLike;
+import econo.buddybridge.post.entity.PostType;
+import econo.buddybridge.post.exception.PostInvalidSortValueException;
+import lombok.RequiredArgsConstructor;
+
+import java.util.List;
+import java.util.Optional;
+
+import static econo.buddybridge.post.entity.QPostLike.postLike;
+
+@RequiredArgsConstructor
+public class PostLikeRepositoryCustomImpl implements PostLikeRepositoryCustom {
+
+    private final JPAQueryFactory queryFactory;
+
+    @Override
+    public Optional<PostLike> findByPostIdAndMemberId(Long postId, Long memberId) {
+
+        PostLike like = queryFactory.selectFrom(postLike)
+                .where(postLike.post.id.eq(postId).and(postLike.member.id.eq(memberId)))
+                .fetchOne();
+
+        return Optional.ofNullable(like);
+    }
+
+    @Override
+    public PostCustomPage findPostsByLikes(Long memberId, Integer page, Integer size, String sort, PostType postType) {
+
+        // Todo: 쿼리 최적화 고려
+        List<PostResDto> content = queryFactory
+                .select(postLike.post)
+                .from(postLike)
+                .where(postLike.member.id.eq(memberId), buildPostTypeExpression(postType))
+                .offset((long) page * size)
+                .orderBy(buildOrderSpecifier(sort))
+                .fetch()
+                .stream()
+                .map(PostResDto::new)
+                .toList();
+
+        Long totalElements = queryFactory
+                .select(postLike.count())
+                .from(postLike)
+                .where(postLike.member.id.eq(memberId))
+                .fetchOne();
+
+        return new PostCustomPage(content, totalElements, content.size() < size);
+    }
+
+
+    private BooleanExpression buildPostTypeExpression(PostType postType) {
+        return postType != null ? postLike.post.postType.eq(postType) : null;
+    }
+
+    private OrderSpecifier<?> buildOrderSpecifier(String sort) {
+        return switch (sort.toLowerCase()) {
+            case "desc" -> postLike.post.createdAt.desc();
+            case "asc" -> postLike.post.createdAt.asc();
+            default -> throw PostInvalidSortValueException.EXCEPTION;
+        };
+    }
+
+}

src/main/java/econo/buddybridge/post/repository/PostRepository.java

@@ -1,10 +1,7 @@
 package econo.buddybridge.post.repository;
 
 import econo.buddybridge.post.entity.Post;
-import econo.buddybridge.post.entity.PostType;
 import lombok.NonNull;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
 
@@ -16,5 +13,4 @@ public interface PostRepository extends JpaRepository<Post, Long> {
     @EntityGraph(attributePaths = {"author"})
     Optional<Post> findById(Long postId);
 
-    Page<Post> findByPostType(Pageable pageable, PostType postType);
 }

src/main/java/econo/buddybridge/post/repository/PostRepositoryImpl.java

@@ -10,6 +10,7 @@
 import econo.buddybridge.post.entity.District;
 import econo.buddybridge.post.entity.PostStatus;
 import econo.buddybridge.post.entity.PostType;
+import econo.buddybridge.post.exception.PostInvalidSortValueException;
 import lombok.RequiredArgsConstructor;
 
 import java.util.List;
@@ -100,7 +101,7 @@ private OrderSpecifier<?> buildOrderSpecifier(String sort) {
         return switch (sort.toLowerCase()) {
             case "desc" -> post.createdAt.desc();
             case "asc" -> post.createdAt.asc();
-            default -> throw new IllegalArgumentException("올바르지 않은 정렬 방식입니다.");
+            default -> throw PostInvalidSortValueException.EXCEPTION;
         };
     }
 }

src/main/java/econo/buddybridge/post/service/PostLikeService.java

@@ -0,0 +1,51 @@
+package econo.buddybridge.post.service;
+
+import econo.buddybridge.member.entity.Member;
+import econo.buddybridge.member.service.MemberService;
+import econo.buddybridge.post.dto.PostCustomPage;
+import econo.buddybridge.post.entity.Post;
+import econo.buddybridge.post.entity.PostLike;
+import econo.buddybridge.post.entity.PostType;
+import econo.buddybridge.post.repository.PostLikeRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class PostLikeService {
+
+    private final MemberService memberService;
+    private final PostService postService;
+    private final PostLikeRepository postLikeRepository;
+
+    @Transactional
+    public Boolean managePostLike(Long memberId, Long postId) {
+
+        Member member = memberService.findMemberByIdOrThrow(memberId);
+        Post post = postService.findPostByIdOrThrow(postId);
+
+        return postLikeRepository.findByPostIdAndMemberId(postId, memberId)
+                .map(this::removeLike)
+                .orElseGet(() -> addLike(post, member));
+    }
+
+    private boolean removeLike(PostLike postLike) {
+        postLikeRepository.delete(postLike);
+        return false;
+    }
+
+    private boolean addLike(Post post, Member member) {
+        PostLike newLike = new PostLike(post, member);
+        postLikeRepository.save(newLike);
+        return true;
+    }
+
+    @Transactional(readOnly = true)
+    public PostCustomPage getPostsLikes(Long memberId, Integer page, Integer size, String sort, PostType postType) {
+        return postLikeRepository.findPostsByLikes(memberId, page - 1, size, sort, postType);
+    }
+
+
+
+}