[NB-48, NB-155] 메인 화면에서의 게시글 조회 구현

src/main/java/com/soyeon/nubim/domain/comment/CommentMapper.java

@@ -6,21 +6,15 @@
 import com.soyeon.nubim.domain.comment.dto.CommentCreateResponseDto;
 import com.soyeon.nubim.domain.comment.dto.CommentResponseDto;
 import com.soyeon.nubim.domain.post.Post;
-import com.soyeon.nubim.domain.post.PostService;
 import com.soyeon.nubim.domain.user.User;
-import com.soyeon.nubim.domain.user.UserService;
+import com.soyeon.nubim.domain.user.dto.UserSimpleResponseDto;
 
 import lombok.RequiredArgsConstructor;
 
 @RequiredArgsConstructor
 @Component
 public class CommentMapper {
-	private final PostService postService;
-	private final UserService userService;
-
-	public Comment toEntity(CommentCreateRequestDto commentCreateRequestDto, User user) {
-		Post post = postService.findPostByIdOrThrow(commentCreateRequestDto.getPostId());
-
+	public Comment toEntity(CommentCreateRequestDto commentCreateRequestDto, User user, Post post) {
 		return Comment.builder()
 			.user(user)
 			.post(post)
@@ -39,10 +33,10 @@ public CommentCreateResponseDto toCommentCreateResponseDto(Comment comment) {
 			.build();
 	}
 
-	public CommentResponseDto toCommentResponseDto(Comment comment) {
+	public CommentResponseDto toCommentResponseDto(Comment comment, UserSimpleResponseDto userSimpleResponseDto) {
 		return CommentResponseDto.builder()
 			.commentId(comment.getCommentId())
-			.userId(comment.getUser().getUserId())
+			.user(userSimpleResponseDto)
 			.postId(comment.getPost().getPostId())
 			.parentCommentId(null) // TODO : 대댓글 구현 시 수정
 			.content(comment.getCommentContent())

src/main/java/com/soyeon/nubim/domain/comment/CommentService.java

@@ -7,18 +7,25 @@
 import com.soyeon.nubim.domain.comment.dto.CommentCreateRequestDto;
 import com.soyeon.nubim.domain.comment.dto.CommentCreateResponseDto;
 import com.soyeon.nubim.domain.comment.dto.CommentResponseDto;
+import com.soyeon.nubim.domain.post.Post;
+import com.soyeon.nubim.domain.post.PostService;
 import com.soyeon.nubim.domain.user.User;
+import com.soyeon.nubim.domain.user.UserMapper;
+import com.soyeon.nubim.domain.user.dto.UserSimpleResponseDto;
 
 import lombok.RequiredArgsConstructor;
 
 @RequiredArgsConstructor
 @Service
 public class CommentService {
 	private final CommentRepository commentRepository;
+	private final PostService postService;
 	private final CommentMapper commentMapper;
+	private final UserMapper userMapper;
 
 	public CommentCreateResponseDto createComment(CommentCreateRequestDto commentCreateRequestDto, User user) {
-		Comment comment = commentMapper.toEntity(commentCreateRequestDto, user);
+		Post post = postService.findPostByIdOrThrow(commentCreateRequestDto.getPostId());
+		Comment comment = commentMapper.toEntity(commentCreateRequestDto, user, post);
 		commentRepository.save(comment); // TODO : 글자 수 검증 필요
 
 		return commentMapper.toCommentCreateResponseDto(comment);
@@ -27,6 +34,9 @@ public CommentCreateResponseDto createComment(CommentCreateRequestDto commentCre
 	public Page<CommentResponseDto> findCommentsByPostIdAndPageable(Long postId, Pageable pageable) {
 		Page<Comment> commentList = commentRepository.findByPostPostId(postId, pageable);
 
-		return commentList.map(commentMapper::toCommentResponseDto);
+		return commentList.map(comment -> {
+			UserSimpleResponseDto userSimpleResponseDto = userMapper.toUserSimpleResponseDto(comment.getUser());
+			return commentMapper.toCommentResponseDto(comment, userSimpleResponseDto);
+		});
 	}
 }

src/main/java/com/soyeon/nubim/domain/comment/dto/CommentResponseDto.java

@@ -1,5 +1,7 @@
 package com.soyeon.nubim.domain.comment.dto;
 
+import com.soyeon.nubim.domain.user.dto.UserSimpleResponseDto;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;
@@ -9,7 +11,7 @@
 @Builder
 public class CommentResponseDto {
 	private Long commentId;
-	private Long userId;
+	private UserSimpleResponseDto user;
 	private Long postId;
 	private Long parentCommentId;
 	private String content;

src/main/java/com/soyeon/nubim/domain/post/CustomPageImpl.java

@@ -0,0 +1,20 @@
+package com.soyeon.nubim.domain.post;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+
+import lombok.Getter;
+import lombok.Setter;
+
+/**
+ * 랜덤 시드값 전송을 위한 커스텀 클래스
+ */
+@Setter
+@Getter
+public class CustomPageImpl<T> extends PageImpl<T> {
+	private Float randomSeed;
+
+	public CustomPageImpl(Page<T> page) {
+		super(page.getContent(), page.getPageable(), page.getTotalElements());
+	}
+}

src/main/java/com/soyeon/nubim/domain/post/Post.java

@@ -20,6 +20,7 @@
 import jakarta.persistence.JoinColumn;
 import jakarta.persistence.ManyToOne;
 import jakarta.persistence.OneToMany;
+import jakarta.persistence.OrderBy;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Getter;
@@ -56,5 +57,6 @@ public class Post extends BaseEntity {
 
 	@Builder.Default
 	@OneToMany(mappedBy = "post", fetch = FetchType.LAZY)
+	@OrderBy("createdAt DESC")
 	private List<Comment> comments = new ArrayList<>();
 }

src/main/java/com/soyeon/nubim/domain/post/PostControllerV1.java

@@ -19,11 +19,13 @@
 
 import com.soyeon.nubim.domain.post.dto.PostCreateRequestDto;
 import com.soyeon.nubim.domain.post.dto.PostCreateResponseDto;
+import com.soyeon.nubim.domain.post.dto.PostMainResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostSimpleResponseDto;
 import com.soyeon.nubim.domain.user.User;
 import com.soyeon.nubim.domain.user.UserService;
 
 import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
 import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 
@@ -35,8 +37,10 @@ public class PostControllerV1 {
 	private final PostService postService;
 	private final UserService userService;
 
-	private static final int DEFAULT_PAGE_SIZE = 10;
+	private static final int DEFAULT_SIMPLE_PAGE_SIZE = 10;
+	private static final int DEFAULT_MAIN_PAGE_SIZE = 5;
 	private static final String DEFAULT_ORDER_BY = "createdAt";
+	private static final int DEFAULT_RECENT_CRITERIA_DAYS = 3;
 
 	@PostMapping
 	public ResponseEntity<PostCreateResponseDto> createPost(
@@ -73,10 +77,10 @@ public ResponseEntity<Page<PostSimpleResponseDto>> getPostsByUserId(
 
 		PageRequest pageRequest;
 		if (sort.equals("desc")) {
-			pageRequest = PageRequest.of(page.intValue(), DEFAULT_PAGE_SIZE,
+			pageRequest = PageRequest.of(page.intValue(), DEFAULT_SIMPLE_PAGE_SIZE,
 				Sort.by(Sort.Direction.DESC, DEFAULT_ORDER_BY));
 		} else if (sort.equals("asc")) {
-			pageRequest = PageRequest.of(page.intValue(), DEFAULT_PAGE_SIZE,
+			pageRequest = PageRequest.of(page.intValue(), DEFAULT_SIMPLE_PAGE_SIZE,
 				Sort.by(Sort.Direction.ASC, DEFAULT_ORDER_BY));
 		} else {
 			return ResponseEntity.badRequest().build();
@@ -94,4 +98,26 @@ public ResponseEntity<Void> deletePost(@PathVariable Long postId) {
 		return ResponseEntity.ok().build();
 	}
 
+	@Operation(description = "메인 화면에서 노출되는 게시글 조회")
+	@GetMapping("/main-posts")
+	public ResponseEntity<Page<PostMainResponseDto>> getMainPosts(
+		@RequestParam(defaultValue = "0") Long page,
+		@RequestParam(defaultValue = "follow") @Parameter(description = "[ follow, random ]") String type,
+		@RequestParam(required = false) Float randomSeed) {
+		User user = userService.getCurrentUser();
+
+		if (type.equals("follow")) { // 팔로우 기반 게시글 조회
+			PageRequest pageRequest = PageRequest.of(
+				page.intValue(), DEFAULT_MAIN_PAGE_SIZE, Sort.by(Sort.Direction.DESC, DEFAULT_ORDER_BY));
+
+			return ResponseEntity.ok(
+				postService.findRecentPostsOfFollowees(user, pageRequest, DEFAULT_RECENT_CRITERIA_DAYS));
+		} else if (type.equals("random")) { // 랜덤 추천 게시글 조회
+			PageRequest pageRequest = PageRequest.of(page.intValue(), DEFAULT_MAIN_PAGE_SIZE);
+
+			return ResponseEntity.ok(postService.findRandomPosts(pageRequest, randomSeed, user));
+		} else {
+			return ResponseEntity.badRequest().build();
+		}
+	}
 }

src/main/java/com/soyeon/nubim/domain/post/PostMapper.java

@@ -6,28 +6,22 @@
 import org.springframework.stereotype.Component;
 
 import com.soyeon.nubim.domain.album.Album;
-import com.soyeon.nubim.domain.album.AlbumNotFoundException;
-import com.soyeon.nubim.domain.album.AlbumService;
 import com.soyeon.nubim.domain.comment.Comment;
+import com.soyeon.nubim.domain.comment.dto.CommentResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostCreateRequestDto;
 import com.soyeon.nubim.domain.post.dto.PostCreateResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostDetailResponseDto;
+import com.soyeon.nubim.domain.post.dto.PostMainResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostSimpleResponseDto;
 import com.soyeon.nubim.domain.user.User;
-import com.soyeon.nubim.domain.user.UserService;
+import com.soyeon.nubim.domain.user.dto.UserSimpleResponseDto;
 
 import lombok.RequiredArgsConstructor;
 
 @Component
 @RequiredArgsConstructor
 public class PostMapper {
-	private final UserService userService;
-	private final AlbumService albumService;
-
-	public Post toEntity(PostCreateRequestDto postCreateRequestDto, User authorUser) {
-		Album linkedAlbum = albumService
-			.findById(postCreateRequestDto.getAlbumId())
-			.orElseThrow(() -> new AlbumNotFoundException(postCreateRequestDto.getAlbumId()));
+	public Post toEntity(PostCreateRequestDto postCreateRequestDto, User authorUser, Album linkedAlbum) {
 
 		return Post.builder()
 			.postTitle(postCreateRequestDto.getPostTitle())
@@ -63,13 +57,41 @@ public PostDetailResponseDto toPostDetailResponseDto(Post post) {
 	}
 
 	public PostSimpleResponseDto toPostSimpleResponseDto(Post post) {
+		UserSimpleResponseDto userSimpleResponseDto = UserSimpleResponseDto.builder()
+			.userId(post.getUser().getUserId())
+			.profileImageUrl(post.getUser().getProfileImageUrl())
+			.nickname(post.getUser().getNickname())
+			.build();
+
 		return PostSimpleResponseDto.builder()
 			.postId(post.getPostId())
 			.postTitle(post.getPostTitle())
 			.postContent(post.getPostContent())
 			.numberOfComments((long)post.getComments().size())
+			.user(userSimpleResponseDto)
+			.albumId(post.getAlbum().getAlbumId())
+			.createdAt(post.getCreatedAt())
+			.updatedAt(post.getUpdatedAt())
+			.build();
+	}
+
+	public PostMainResponseDto toPostMainResponseDto(Post post, CommentResponseDto representativeComment) {
+		UserSimpleResponseDto userSimpleResponseDto = UserSimpleResponseDto.builder()
 			.userId(post.getUser().getUserId())
+			.profileImageUrl(post.getUser().getProfileImageUrl())
+			.nickname(post.getUser().getNickname())
+			.build();
+
+		return PostMainResponseDto.builder()
+			.postId(post.getPostId())
+			.postTitle(post.getPostTitle())
+			.postContent(post.getPostContent())
+			.numberOfComments((long)post.getComments().size())
+			.representativeComment(representativeComment)
+			.user(userSimpleResponseDto)
 			.albumId(post.getAlbum().getAlbumId())
+			.createdAt(post.getCreatedAt())
+			.updatedAt(post.getUpdatedAt())
 			.build();
 	}
 }

src/main/java/com/soyeon/nubim/domain/post/PostRepository.java

@@ -1,15 +1,30 @@
 package com.soyeon.nubim.domain.post;
 
+import java.time.LocalDateTime;
 import java.util.List;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
+import com.soyeon.nubim.domain.user.User;
+
 @Repository
 public interface PostRepository extends JpaRepository<Post, Long> {
 	List<Post> findByUserUserId(Long userId);
 
 	Page<Post> findByUserUserId(Long postPostId, Pageable pageable);
+
+	@Query("SELECT p FROM Post p WHERE p.user IN " +
+		"(SELECT uf.followee FROM UserFollow uf WHERE uf.follower = :user) " +
+		"AND p.createdAt >= :criteriaDays AND p.isDeleted = false")
+	Page<Post> findRecentPostsByFollowees(User user, LocalDateTime criteriaDays, Pageable pageable);
+
+	@Query(value = "SELECT SETSEED(:seed)", nativeQuery = true)
+	void setSeed(Float seed);
+
+	@Query(value = "SELECT p FROM Post p WHERE p.user != :user ORDER BY function('RANDOM')")
+	Page<Post> findRandomPostsExceptMine(Pageable pageable, User user);
 }

src/main/java/com/soyeon/nubim/domain/post/PostService.java

@@ -1,16 +1,28 @@
 package com.soyeon.nubim.domain.post;
 
+import java.time.LocalDateTime;
+import java.util.Random;
+
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
 
+import com.soyeon.nubim.domain.album.Album;
+import com.soyeon.nubim.domain.album.AlbumNotFoundException;
+import com.soyeon.nubim.domain.album.AlbumService;
+import com.soyeon.nubim.domain.comment.Comment;
+import com.soyeon.nubim.domain.comment.CommentMapper;
+import com.soyeon.nubim.domain.comment.dto.CommentResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostCreateRequestDto;
 import com.soyeon.nubim.domain.post.dto.PostCreateResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostDetailResponseDto;
+import com.soyeon.nubim.domain.post.dto.PostMainResponseDto;
 import com.soyeon.nubim.domain.post.dto.PostSimpleResponseDto;
 import com.soyeon.nubim.domain.post.exceptions.PostNotFoundException;
 import com.soyeon.nubim.domain.post.exceptions.UnauthorizedAccessException;
 import com.soyeon.nubim.domain.user.User;
+import com.soyeon.nubim.domain.user.UserMapper;
+import com.soyeon.nubim.domain.user.dto.UserSimpleResponseDto;
 
 import lombok.RequiredArgsConstructor;
 
@@ -19,6 +31,11 @@
 public class PostService {
 	private final PostRepository postRepository;
 	private final PostMapper postMapper;
+	private final AlbumService albumService;
+
+	private static final Random random = new Random();
+	private final CommentMapper commentMapper;
+	private final UserMapper userMapper;
 
 	public PostDetailResponseDto findPostDetailById(Long id) {
 		Post post = postRepository.findById(id).orElseThrow(() -> new PostNotFoundException(id));
@@ -39,7 +56,10 @@ public Page<PostSimpleResponseDto> findAllPostsByUserIdOrderByCreatedAt(Long use
 	}
 
 	public PostCreateResponseDto createPost(PostCreateRequestDto postCreateRequestDto, User authorUser) {
-		Post post = postMapper.toEntity(postCreateRequestDto, authorUser);
+		Album linkedAlbum = albumService
+			.findById(postCreateRequestDto.getAlbumId())
+			.orElseThrow(() -> new AlbumNotFoundException(postCreateRequestDto.getAlbumId()));
+		Post post = postMapper.toEntity(postCreateRequestDto, authorUser, linkedAlbum);
 		postRepository.save(post);
 		return postMapper.toPostCreateResponseDto(post);
 	}
@@ -68,4 +88,42 @@ public void validatePostOwner(Long postId, User author) {
 			throw new UnauthorizedAccessException(postId);
 		}
 	}
+
+	public Page<PostMainResponseDto> findRecentPostsOfFollowees(
+		User user, Pageable pageable, int recentCriteriaDays) {
+		return postRepository.findRecentPostsByFollowees(user, LocalDateTime.now().minusDays(recentCriteriaDays),
+				pageable)
+			.map(post -> postMapper.toPostMainResponseDto(post, findRecentCommentByPostOrNull(post)));
+	}
+
+	public Page<PostMainResponseDto> findRandomPosts(Pageable pageable, Float randomSeed, User user) {
+		float seed = getOrGenerateRandomSeed(randomSeed);
+		postRepository.setSeed(seed);
+
+		CustomPageImpl<PostMainResponseDto> customPage = new CustomPageImpl<>(
+			postRepository.findRandomPostsExceptMine(pageable, user)
+				.map(post -> postMapper.toPostMainResponseDto(post, findRecentCommentByPostOrNull(post)))
+		);
+		customPage.setRandomSeed(seed);
+
+		return customPage;
+	}
+
+	private Float getOrGenerateRandomSeed(Float seed) {
+		if (seed == null) {
+			return random.nextFloat();
+		}
+		return seed;
+	}
+
+	private CommentResponseDto findRecentCommentByPostOrNull(Post post) {
+		Comment lastCommentByPost = post.getComments().stream().findFirst().orElse(null);
+		if (lastCommentByPost == null) {
+			return null;
+		} else {
+			UserSimpleResponseDto userSimpleResponseDto = userMapper.toUserSimpleResponseDto(
+				lastCommentByPost.getUser());
+			return commentMapper.toCommentResponseDto(lastCommentByPost, userSimpleResponseDto);
+		}
+	}
 }