[스프링부트] 20. Blog v2 : Board

1. 글 쓰기

• 글을 작성했을 때 Relation Mapping을 통해 쿼리 없이 자동으로 DB에 데이터가 들어가도록 설정

• BoardController
• 글을 작성하고 글쓰기완료 버튼을 누르면 session 정보와 DTO를 전송

@GetMapping("/board/save-form")
    public String saveForm(HttpSession session) {
        User validatedUser = (User) session.getAttribute("validatedUser");
        if (validatedUser == null) throw new RuntimeException("인증이 필요합니다.");
        return "board/save-form";
    }

    @PostMapping("/board/save")
    public String save(BoardRequest.SaveDTO saveDTO, HttpSession session) {
        User validatedUser = (User) session.getAttribute("validatedUser");
        if (validatedUser == null) throw new RuntimeException("인증이 필요합니다.");
        boardService.글쓰기(saveDTO, validatedUser);
        return "redirect:/";
    }

• BoardRequest
• user 정보를 세션에서 받아옴

@Data
    public static class SaveDTO {
        private String title;
        private String content;
        private String isPublic;

        public Board toEntity(User user) {
            return Board.builder()
                    .title(title)
                    .content(content)
                    .isPublic(isPublic == null ? false : true)
                    .user(user)
                    .build();
        }
    }

• BoardService

@Transactional
    public void 글쓰기(BoardRequest.SaveDTO saveDTO, User user) {
        Board board = saveDTO.toEntity(user);
        boardRepository.write(board);
    }

• BoardRepository

public void write(Board board) {
        em.persist(board);
    }

• board/save-form.mustache

{{> layout/header}}

<div class="container p-5">

    <div class="card">
        <div class="card-header"><b>글쓰기 화면입니다</b></div>
        <div class="card-body">
            <form action="/board/save" method="post">
                <div class="mb-3">
                    <input type="text" class="form-control" placeholder="Enter title" name="title">
                </div>
                <div class="mb-3">
                    <textarea class="form-control" rows="5" name="content"></textarea>
                </div>
                <!-- ✅ 공개 여부 체크박스 -->
                <div class="form-check mb-3">
                    <input class="form-check-input" type="checkbox" name="isPublic">
                    <label class="form-check-label" for="isPublic">
                        공개 글로 작성하기
                    </label>
                </div>
                <button class="btn btn-primary form-control">글쓰기완료</button>
            </form>

        </div>
    </div>
</div>

{{> layout/footer}}

결과

• 글을 작성하면 목록 갱신

2. 글 목록

• BoardController
• 작성된 글 목록을 List로 받아 폼에 출력
• 비공개 글은 다른 사람에게 보이면 안되고, 내가 쓴 글은 비공개여도 보여야 함
• 세션 정보를 받아 userId의 여부에 따라 다른 글 목록 표시

@GetMapping("/")
    public String home(HttpServletRequest request, HttpSession session) {
        User validatedUser = (User) session.getAttribute("validatedUser");
        if (validatedUser == null) {
            request.setAttribute("models", boardService.글목록보기(null));
        } else {
            request.setAttribute("models", boardService.글목록보기(validatedUser.getId()));
        }
        return "board/list";
    }

• BoardService

 public List<Board> 글목록보기(Integer userId) {
        return boardRepository.findAll(userId);
    }

• BoardRepository
• userId가 null인지 여부에 따라 2가지의 sql 작동
• userId가 null이 아니면 (로그인했으면) 자신의 글을 보여주어야 함
• where b.isPublic = true or b.user.id = :userId

public List<Board> findAll(Integer userId) {
        String s1 = "select b from Board b where b.isPublic = true or b.user.id = :userId order by b.id desc";
        String s2 = "select b from Board b where b.isPublic = true order by b.id desc";

        Query q = em.createQuery(userId == null ? s2 : s1, Board.class);
        if(userId != null) q.setParameter("userId", userId);
        return q.getResultList();
    }

• board/list.mustache

{{> layout/header}}

<div class="container p-5">

    <div class="mb-3 d-flex justify-content-end">
        <form class="d-flex">
            <input class="form-control me-2" type="text" placeholder="검색...">
            <button class="btn btn-primary" type="button">Search</button>
        </form>
    </div>

    {{#models}}
        <div class="card mb-3">
            <div class="card-body">
                <div class="d-flex justify-content-between">
                    <h4 class="card-title mb-3">{{title}}</h4>
                    {{^isPublic}}
                        <div class="d-flex align-items-start">
                            <span class="badge bg-secondary">비공개</span>
                        </div>
                    {{/isPublic}}
                </div>
                <a href="/board/{{id}}" class="btn btn-primary">상세보기</a>
            </div>
        </div>
    {{/models}}

    <ul class="pagination d-flex justify-content-center">
        <li class="page-item disabled"><a class="page-link" href="#">Previous</a></li>
        <li class="page-item"><a class="page-link" href="#">Next</a></li>
    </ul>

</div>

{{> layout/footer}}

@Autowired // DI
    private BoardRepository boardRepository;

    @Test
    public void findAll_test() {
        // given

        // when
        List<Board> boardList = boardRepository.findAll();

        // Lazy -> Board -> User(id=1)
        // Eager -> N+1  -> Board조회 -> 연관된 User 유저 수 만큼 주회
        // Eager -> Join -> 한방쿼리
        System.out.println("--------------------");
        boardList.get(0).getUser().getUsername();
        System.out.println("--------------------");
        // eye
    }

Hibernate: 
    select
        b1_0.id,
        b1_0.content,
        b1_0.created_at,
        b1_0.is_public,
        b1_0.title,
        b1_0.user_id 
    from
        board_tb b1_0
Hibernate: 
    select
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        user_tb u1_0 
    where
        u1_0.id=?
Hibernate: 
    select
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        user_tb u1_0 
    where
        u1_0.id=?
Hibernate: 
    select
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        user_tb u1_0 
    where
        u1_0.id=?

insert into board_tb(title, content, user_id, is_public, created_at)
values ('제목1', '내용1', 1, true, now());
insert into board_tb(title, content, user_id, is_public, created_at)
values ('제목2', '내용2', 1, true, now());
insert into board_tb(title, content, user_id, is_public, created_at)
values ('제목3', '내용3', 2, true, now());
insert into board_tb(title, content, user_id, is_public, created_at)
values ('제목4', '내용4', 3, true, now());

Hibernate: 
    select
        b1_0.id,
        b1_0.content,
        b1_0.created_at,
        b1_0.is_public,
        b1_0.title,
        b1_0.user_id 
    from
        board_tb b1_0
Hibernate: 
    select
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        user_tb u1_0 
    where
        u1_0.id=?

Hibernate: 
    select
        b1_0.id,
        b1_0.content,
        b1_0.created_at,
        b1_0.is_public,
        b1_0.title,
        b1_0.user_id 
    from
        board_tb b1_0

Hibernate: 
    select
        b1_0.id,
        b1_0.content,
        b1_0.created_at,
        b1_0.is_public,
        b1_0.title,
        b1_0.user_id 
    from
        board_tb b1_0
--------------------
Hibernate: 
    select
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        user_tb u1_0 
    where
        u1_0.id=?
--------------------

결과

• 로그인 안 했을 때

• ssar로 로그인 했을 때 (비공개 글)

3. 글 상세보기

• BoardController
• 글을 작성하고 글쓰기완료 버튼을 누르면 session 정보와 DTO를 전송

@GetMapping("/board/{id}")
    public String detailForm(@PathVariable("id") int id, HttpSession session, HttpServletRequest request) {
        Integer userId = null;

        User validatedUser = (User) session.getAttribute("validatedUser");
        if(validatedUser != null) userId = validatedUser.getId();
        BoardResponse.DetailDTO board = boardService.글상세보기(id, userId);
        request.setAttribute("model", board);
        return "board/detail";
    }

• BoardResponse
• 글쓴이와 로그인한 유저가 일치해야 수정, 삭제 표시가 가능
• isOwner 속성 추가

@Data
    public static class DetailDTO {
        private Integer id;
        private String title;
        private String content;
        private Boolean isPublic;
        private Boolean isOwner;
        private Integer userId;
        private String username;
        private Timestamp createdAt;


        public DetailDTO(Board board, Integer sessionUserId) {
            this.id = board.getId();
            this.title = board.getTitle();
            this.content = board.getContent();
            this.isPublic = board.getIsPublic();
            this.isOwner = board.getUser().getId() == sessionUserId;
            this.userId = board.getUser().getId();
            this.username = board.getUser().getUsername();
            this.createdAt = board.getCreatedAt();
        }
    }

• BoardService

public BoardResponse.DetailDTO 글상세보기(int id, Integer sessionUserId) {
        BoardResponse.DetailDTO detailDTO = new BoardResponse.DetailDTO(boardRepository.findByIdJoinUser(id), sessionUserId);
        return detailDTO;
    }

• BoardRepository

public Board findByIdJoinUser(int id) {
        // inner join은 on 절 생략 가능
        Query q = em.createQuery("select b from Board b join fetch b.user where b.id = :id", Board.class);
        q.setParameter("id", id);
        return (Board) q.getSingleResult();
    }

• board/detail.mustache

{{> layout/header}}
<div class="container p-5">

    {{#model.isOwner}}
        <!-- 수정삭제버튼 -->
        <div class="d-flex justify-content-end">
            <a href="/board/{{model.id}}/update-form" class="btn btn-warning me-1">수정</a>
            <form action="/board/{{model.id}}/delete" method="post">
                <button class="btn btn-danger">삭제</button>
            </form>
        </div>
    {{/model.isOwner}}

    <div class="d-flex justify-content-end">
        <b>작성자</b> : {{model.username}}
    </div>

    <!-- 게시글내용 -->
    <div>
        <h2><b>{{model.title}}</b></h2>
        <hr/>
        <div class="m-4 p-2">
            {{model.content}}
        </div>
    </div>

    <!-- AJAX 좋아요 영역 -->
    <div class="my-3 d-flex align-items-center">
        <span class="my-like-heart" onclick="likeToggle()">&#10084;</span>
        <span><b id="likeCount">12</b>명이 이 글을 좋아합니다</span>
    </div>

    <!-- 댓글 -->
    <div class="card mt-3">
        <!-- 댓글등록 -->
        <div class="card-body">
            <form action="/reply/save" method="post">
                <textarea class="form-control" rows="2" name="comment"></textarea>
                <div class="d-flex justify-content-end">
                    <button type="submit" class="btn btn-outline-primary mt-1">댓글등록</button>
                </div>
            </form>
        </div>

        <!-- 댓글목록 -->
        <div class="card-footer">
            <b>댓글리스트</b>
        </div>
        <div class="list-group">
            <!-- 댓글아이템 -->
            <div class="list-group-item d-flex justify-content-between align-items-center">
                <div class="d-flex">
                    <div class="px-1 me-1 bg-primary text-white rounded">cos</div>
                    <div>댓글 내용입니다</div>
                </div>
                <form action="/reply/1/delete" method="post">
                    <button class="btn">🗑</button>
                </form>
            </div>
            <!-- 댓글아이템 -->
            <div class="list-group-item d-flex justify-content-between align-items-center">
                <div class="d-flex">
                    <div class="px-1 me-1 bg-primary text-white rounded">ssar</div>
                    <div>댓글 내용입니다</div>
                </div>
                <form action="/reply/1/delete" method="post">
                    <button class="btn">🗑</button>
                </form>
            </div>
        </div>
    </div>
</div>

<script>
    function likeToggle() {
        let likeHeart = document.querySelector('.my-like-heart');
        console.log(likeHeart);
        likeHeart.classList.toggle('liked');
    }
</script>

{{> layout/footer}}

@Test
    public void findByIdJoinUser_test() {
        // given
        int id = 1;
        // when
        Board board = boardRepository.findByIdJoinUser(id);
        // eye
        System.out.println(board);
    }

Hibernate: 
    select
        b1_0.id,
        b1_0.content,
        b1_0.created_at,
        b1_0.is_public,
        b1_0.title,
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        board_tb b1_0 
    join
        user_tb u1_0 
            on u1_0.id=b1_0.user_id 
    where
        b1_0.id=?
Board{id=1, title='제목1', content='내용1', isPublic=true, user=User{id=1, username='ssar', password='1234', email='ssar@nate.com', createdAt=2025-04-07 14:42:21.914297}, createdAt=2025-04-07 14:42:21.91629}

Hibernate: 
    select
        b1_0.id,
        b1_0.content,
        b1_0.created_at,
        b1_0.is_public,
        b1_0.title,
        b1_0.user_id 
    from
        board_tb b1_0 
    join
        user_tb u1_0 
            on u1_0.id=b1_0.user_id 
    where
        b1_0.id=?
Hibernate: 
    select
        u1_0.id,
        u1_0.created_at,
        u1_0.email,
        u1_0.password,
        u1_0.username 
    from
        user_tb u1_0 
    where
        u1_0.id=?
Board{id=1, title='제목1', content='내용1', isPublic=true, user=User{id=1, username='ssar', password='1234', email='ssar@nate.com', createdAt=2025-04-07 14:44:58.553253}, createdAt=2025-04-07 14:44:58.555246}

결과

• 로그인 안 했을 때
• 수정, 삭제 버튼이 보이지 않음

• 로그인 했을 때 1
• 자신의 글은 수정, 삭제 버튼 확인 가능

• 로그인 했을 때 2
• 다른 사람의 글은 수정, 삭제 버튼 확인 불가

4. 글 삭제

• BoardController

@PostMapping("/board/{id}/delete")
    public String delete(@PathVariable("id") Integer id) {
        User sessionUser = (User) session.getAttribute("sessionUser");
        if (sessionUser == null) throw new Exception401("인증이 필요합니다");
        boardService.글삭제(id);
        return "redirect:/";
    }

• BoardService

@PostMapping("/board/{id}/delete")
    public String delete(@PathVariable("id") Integer id) {
        User sessionUser = (User) session.getAttribute("sessionUser");
        boardService.글삭제(id, sessionUser.getId());
        return "redirect:/";
    }

• BoardRepository
• em.remove : 영속성을 활용하여 cascade로 연결되어 있는 객체들까지 한 번에 삭제 가능
• em.remove(em.find(Board.class, id)) : id가 일치하는 board의 연관 객체들 전부 삭제
• delete cascade from board_tb where id = ‘id’;

public void deleteById(Integer id) {
        em.remove(em.find(Board.class, id));
    }

5. 글 수정

• BoardController

@GetMapping("/board/{id}/update-form")
    public String updateForm(@PathVariable("id") Integer id, BoardRequest.UpdateDTO updateDTO, HttpServletRequest request) {
        User sessionUser = (User) session.getAttribute("sessionUser");
        if (sessionUser == null) throw new Exception401("인증이 필요합니다");
        Board boardPS = boardService.글수정화면(updateDTO, id);
        request.setAttribute("model", boardPS);
        return "board/update-form";
    }

@PostMapping("/board/{id}/update")
    public String update(@PathVariable("id") Integer id, BoardRequest.UpdateDTO updateDTO) {
        User sessionUser = (User) session.getAttribute("sessionUser");
        if (sessionUser == null) throw new Exception401("인증이 필요합니다");
        boardService.글수정(updateDTO, sessionUser.getId(), id);
        return "redirect:/board/"+id;
    }

• BoardRequest
• isPublic은 on 또는 null 값이 리턴됨
• true/false 값을 받아야 하므로 이를 체크할 수 있는 isPublicChecked() 메서드 추가
• String인 isPublic이 on이면 true, 아니면 false

@Data
    public static class UpdateDTO {
        private String title;
        private String content;
        private String isPublic; // "on" or null

        public Boolean isPublicChecked() {
            return "on".equals(isPublic);
        }
    }

• BoardService
• Update는 Dirty Checking을 사용하여 board 객체 내부 값을 setter로 변경
• Transaction이 끝나면 자동 update

public Board 글수정화면(BoardRequest.UpdateDTO updateDTO, Integer id) {
        return boardRepository.findByIdJoinUserAndReplies(id);
    }

@Transactional
    public void 글수정(BoardRequest.UpdateDTO updateDTO, Integer userId, Integer boardId) {
        // 1. 글 불러오기 by boardId
        Board board = boardRepository.findById(boardId);
        // 1-1. 글이 없으면 Exception404
        if(board == null) throw new Exception404("해당하는 글이 없습니다.");
        // 2. 글 주인과 userId 비교 : 불일치 시 Exception403
        if(!(board.getUser().getId().equals(userId))) throw new Exception403("권한이 없습니다.");
        // 3. update (dirty checking)
        board.update(updateDTO.getTitle(), updateDTO.getContent(), updateDTO.isPublicChecked());
    }

• BoardRepository

public Board findByIdJoinUserAndReplies(Integer id) {
        Query query = em.createQuery("select b from Board b join fetch b.user left join fetch b.replies r left join fetch r.user where b.id = :id order by r.id desc", Board.class);
        query.setParameter("id", id);
        return (Board) query.getSingleResult();
    }

• Board.update

public void update(String title, String content, Boolean isPublic) {
        this.title = title;
        this.content = content;
        this.isPublic = isPublic;
    }

결과

• 제목, 내용, 공개 글 작성 체크박스 여부를 잘 반영함
• 체크박스 해제 시 개인 글 설정

6. 글 페이징

• Main 화면에 페이지 정보를 추가해야 함 : MainDTO 설계

@Data
    public static class MainDTO {
        private Integer prev;
        private Integer next;
        private Integer current;
        private Integer totalCount;
        private Integer totalPage;
        private Integer size;
        private Boolean isFirst; // currentPage == 0
        private Boolean isLast; // totalCount, totalPage == currentPage
        private Integer pageSize;
        private Integer pageIndex;

        private List<Board> boards;

        private List<Integer> numbers; // 20개 [1, 2, 3, 4, 5, 6, 7] -> {{#model.numbers}} -> {{.}}

        public MainDTO(List<Board> boards, Integer current, Integer totalCount) {
            this.boards = boards;
            this.prev = current - 1;
            this.next = current + 1;
            this.size = 3;
            this.totalCount = totalCount; // given
            this.totalPage = makeTotalPage(totalCount, size);
            this.isFirst = current == 0;
            this.isLast = current == totalPage - 1;
            this.pageSize = 5;
            // 2-1. makeNumbers
            this.numbers = makeNumbers(current, pageSize, totalPage);
            this.pageIndex = 0;
            // 1. 페이지 전체 넣기
            /*
            for (int i = 0; i < totalCount; i++) {
                this.numbers.add(i);
            }
            */
            // 2. 페이지 묶음
            for (int i = 0; i < pageSize; i++) {
                pageIndex = current / pageSize; // 현재 페이지 index : 페이지 목차
                if (i % pageSize == 0) numbers.clear(); // 페이지를 불러올 때마다 페이지 리스트 클리어
                int page = pageIndex * pageSize + i; // 페이지 변수 : 페이지 index * pageSize + i
                // 0 ~ 4 : 0 * 5 + 0~4, 5 ~ 9 : 1 * 5 + 0~4, ...
                if (page < totalPage) numbers.add(page); // 최대 페이지 전까지 추가
            }
        }
        // 2-1. makeNumbers
        private List<Integer> makeNumbers(int current, int pageSize, int totalPage) {
            List<Integer> numbers = new ArrayList<>();

            int start = (current / pageSize) * pageSize;
            int end = Math.min(start + pageSize, totalPage);

            for (int i = start; i < end; i++) {
                numbers.add(i);
            }

            return numbers;
        }

        private Integer makeTotalPage(int totalCount, int size) {
            return totalCount / size + (totalCount % size == 0 ? 0 : 1);
        }
    }

• BoardController
• requestParameter로 현재 페이지를 받아와야 함

@GetMapping("/")
    public String list(HttpServletRequest request, @RequestParam(required = false, value = "page", defaultValue = "0") Integer page) {
        User sessionUser = (User) session.getAttribute("sessionUser");

        if (sessionUser == null) {
            request.setAttribute("model", boardService.글목록보기(null, page));
        } else {
            request.setAttribute("model", boardService.글목록보기(sessionUser.getId(), page));
        }

        return "board/list";
    }

• BoardService
• MainDTO 반환 : 페이지 정보가 추가됨

public BoardResponse.MainDTO 글목록보기(Integer userId, Integer page) {
        if (userId == null) {
            return new BoardResponse.MainDTO(boardRepository.findAll(page), page, boardRepository.totalCount().intValue());
        } else {
            return new BoardResponse.MainDTO(boardRepository.findAll(userId, page), page, boardRepository.totalCount(userId).intValue());
        }
    }

• BoardRepository
• findAll
• setFirstResult(n) → 데이터 인덱스 (어디서부터 찾을건지 확인)
• setMaxResults(n) → 최대 표시 개수 (board 출력 개수)
• totalCount
• count(*)로 총 board 갯수 반환

// localhost:8080?page=0
    public List<Board> findAll(int page) {
        String sql = "select b from Board b where b.isPublic = true order by b.id desc";
        Query query = em.createQuery(sql, Board.class);
        query.setFirstResult(page * 3);
        query.setMaxResults(3);

        return query.getResultList();
    }

    public List<Board> findAll(Integer userId, int page) {
        String sql = "select b from Board b where b.isPublic = true or b.user.id = :userId order by b.id desc";
        Query query = em.createQuery(sql, Board.class);
        query.setParameter("userId", userId);
        query.setFirstResult(page * 3);
        query.setMaxResults(3);
        return query.getResultList();
    }

    // 그룹 함수 : Long 리턴
    // 1. 로그인 안 했을 때 : 4개
    public Long totalCount() {
        Query q = em.createQuery("select count(b) from Board b where b.isPublic = true", Long.class);
        return (Long) q.getSingleResult();
    }

    // 2-1. ssar로 로그인 했을 때 : 5개
    // 2-2. cos로 로그인 했을 때 : 4개
    public Long totalCount(int userId) {
        Query q = em.createQuery("select count(b) from Board b where b.isPublic = true or b.user.id = :userId", Long.class);
        q.setParameter("userId", userId);
        return (Long) q.getSingleResult();
    }

• list.mustache

<ul class="pagination d-flex justify-content-center">
		<li class="page-item {{#model.isFirst}} disabled {{/model.isFirst}}"><a class="page-link"
		                                                                        href="?page={{model.prev}}
			">Previous</a></li>
		{{#model.numbers}}
			<li class="page-item"><a class="page-link" href="?page={{.}}">{{.}}</a></li>
		{{/model.numbers}}
		<li class="page-item {{#model.isLast}} disabled {{/model.isLast}}"><a class="page-link"
		                                                                      href="?page={{model.next}}">Next</a></li>
	</ul>

결과

• 현재 페이지(default)가 0이므로 Previous는 비활성화, 0 ~ 4까지 페이지 번호 출력

• 5페이지가 넘어가면, 페이지 일부만 출력 (글이 20개이므로, 5 ~ 6까지만 출력)

7. 글 검색

• BoardController

@GetMapping("/")
    public String list(HttpServletRequest request, @RequestParam(required = false, value = "page", defaultValue = "0") Integer page,
                       @RequestParam(required = false, value = "keyword", defaultValue = "") String keyword) {
        User sessionUser = (User) session.getAttribute("sessionUser");

        if (sessionUser == null) {
            request.setAttribute("model", boardService.글목록보기(null, page, keyword));
        } else {
            request.setAttribute("model", boardService.글목록보기(sessionUser.getId(), page, keyword));
        }
        System.out.println("keyword : " + keyword);
        return "board/list";
    }

• BoardResponse

@Data
    public static class MainDTO {
        private Integer prev;
        private Integer next;
        private Integer current;
        private Integer totalCount;
        private Integer totalPage;
        private Integer size;
        private Boolean isFirst; // currentPage == 0
        private Boolean isLast; // totalCount, totalPage == currentPage
        private Integer pageSize;
        private String keyword;

        private List<Board> boards;

        private List<Integer> numbers; // 20개 [1, 2, 3, 4, 5, 6, 7] -> {{#model.numbers}} -> {{.}}

        public MainDTO(List<Board> boards, Integer current, Integer totalCount, String keyword) {
            this.boards = boards;
            this.prev = current - 1;
            this.next = current + 1;
            this.size = 3;
            this.totalCount = totalCount; // given
            this.totalPage = makeTotalPage(totalCount, size);
            this.isFirst = current == 0;
            this.isLast = current == totalPage - 1;
            this.pageSize = 5;
            this.numbers = makeNumbers(current, pageSize, totalPage);
            // keyword 값이 있거나 null
            this.keyword = keyword;
            // 1. 페이지 전체 넣기
            /*
            for (int i = 0; i < totalCount; i++) {
                this.numbers.add(i);
            }
            */
            // 2. 페이지 묶음
            /*for (int i = 0; i < pageSize; i++) {
                pageIndex = current / pageSize; // 현재 페이지 index : 페이지 목차
                if (i % pageSize == 0) numbers.clear(); // 페이지를 불러올 때마다 페이지 리스트 클리어
                int page = pageIndex * pageSize + i; // 페이지 변수 : 페이지 index * pageSize + i
                // 0 ~ 4 : 0 * 5 + 0~4, 5 ~ 9 : 1 * 5 + 0~4, ...
                if (page < totalPage) numbers.add(page); // 최대 페이지 전까지 추가
            }*/
        }

• BoardService

public BoardResponse.MainDTO 글목록보기(Integer userId, Integer page, String keyword) {
        if (userId == null) {
            return new BoardResponse.MainDTO(boardRepository.findAll(page, keyword), page, boardRepository.totalCount(keyword).intValue(), keyword);
        } else {
            return new BoardResponse.MainDTO(boardRepository.findAll(userId, page, keyword), page, boardRepository.totalCount(userId, keyword).intValue(), keyword);
        }
    }

• BoardRepository

// localhost:8080?page=0
    public List<Board> findAll(int page, String keyword) {
        String sql = "";
        if (!(keyword.isBlank()))
            sql += "select b from Board b where b.isPublic = true and b.title like :keyword order by b.id desc";
        else sql += "select b from Board b where b.isPublic = true order by b.id desc";
        Query query = em.createQuery(sql, Board.class);
        // keyword를 포함 : title like %keyword%
        if (!(keyword.isBlank())) query.setParameter("keyword", "%" + keyword + "%");
        query.setFirstResult(page * 3);
        query.setMaxResults(3);

        return query.getResultList();
    }

    public List<Board> findAll(Integer userId, int page, String keyword) {
        String sql = "";
        if (!(keyword.isBlank()))
            sql += "select b from Board b where b.isPublic = true or b.user.id = :userId and b.title like :keyword order by b.id desc";
        else sql += "select b from Board b where b.isPublic = true or b.user.id = :userId order by b.id desc";
        Query query = em.createQuery(sql, Board.class);
        // keyword를 포함 : title like %keyword%
        if (!(keyword.isBlank())) query.setParameter("keyword", "%" + keyword + "%");
        query.setParameter("userId", userId);
        query.setFirstResult(page * 3);
        query.setMaxResults(3);

        return query.getResultList();
    }

    // 그룹 함수 : Long 리턴
    // 1. 로그인 안 했을 때 : 4개
    public Long totalCount(String keyword) {
        String sql = "";
        if (!(keyword.isBlank()))
            sql += "select count(b) from Board b where b.isPublic = true and b.title like :keyword";
        else sql += "select count(b) from Board b where b.isPublic = true";
        Query query = em.createQuery(sql, Long.class);
        // keyword를 포함 : title like %keyword%
        if (!(keyword.isBlank())) query.setParameter("keyword", "%" + keyword + "%");
        return (Long) query.getSingleResult();
    }

    // 2-1. ssar로 로그인 했을 때 : 5개
    // 2-2. cos로 로그인 했을 때 : 4개
    public Long totalCount(int userId, String keyword) {
        String sql = "";
        if (!(keyword.isBlank()))
            sql += "select count(b) from Board b where b.isPublic = true or b.user.id = :userId and b.title like :keyword";
        else sql += "select count(b) from Board b where b.isPublic = true or b.user.id = :userId";
        Query query = em.createQuery(sql, Long.class);
        // keyword를 포함 : title like %keyword%
        if (!(keyword.isBlank())) query.setParameter("keyword", "%" + keyword + "%");
        query.setParameter("userId", userId);
        return (Long) query.getSingleResult();
    }

결과

• keyword 검색 시 keyword가 제목에 포함된 글을 찾아 출력, 페이징도 동작 확인