17. 게시판 글쓰기v3

1. View 보기

{{> /layout/header}}

<div class="container p-5">

    <!-- 요청을 하면 localhost:8080/board/save POST로 요청됨
    title=사용자입력값&content=사용자값 -->
    <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>
                <button type="submit" class="btn btn-primary form-control">글쓰기완료</button>
            </form>
        </div>
    </div>
</div>

{{> /layout/footer}}

2. BoardRequest 에 SaveDTO () 만들기

• Board 에 생성자에 @Builder 달기

package shop.mtcoding.blog.board;

import jakarta.persistence.*;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.hibernate.annotations.CreationTimestamp;
import shop.mtcoding.blog.user.User;
import shop.mtcoding.blog.util.MyDateUtil;

import java.sql.Timestamp;

@NoArgsConstructor
@Data // 변경되는 데이터에만 setter가 필요함
@Table(name = "board_tb")
@Entity
public class Board {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String title;
    private String content;
    // private String username;

    // username은 user_tb에도 있기에 외래키로 연관관계 맺어야 함
    // @JoinColumn(name = "user_id") 직접 지정할 때
    @ManyToOne(fetch = FetchType.LAZY) // ORM 할 것이기에 user 객체 필요
    private User user; // DB에 컬럼명 : user_id (변수명_PK키)

    @CreationTimestamp // PC로 인해 DB에 INSERT될 때 날짜 주입
    private Timestamp createdAt;

    @Builder
    public Board(Integer id, String title, String content, User user, Timestamp createdAt) {
        this.id = id;
        this.title = title;
        this.content = content;
        this.user = user;
        this.createdAt = createdAt;
    }

    public String getBoardDate(){
        return MyDateUtil.timestampFormat(createdAt);
    }
}

• SaveDTO() 만들기

package shop.mtcoding.blog.board;

import lombok.Data;
import shop.mtcoding.blog.user.User;

public class BoardRequest {

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

        // DTO를 클라이언트로 부터 받아서, PC에 전달하기 위해 사용
        // insert하는 DTO에서만 만들기
        public Board toEntity(User user){
            return Board.builder()
                    .title(title)
                    .content(content)
                    .user(user)
                    .build();
        }
    }
}

3. BoardRepository 에 save() 만들기

package shop.mtcoding.blog.board;

import jakarta.persistence.EntityManager;
import jakarta.persistence.Query;
import jakarta.transaction.Transactional;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Repository;
import shop.mtcoding.blog.user.User;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

@RequiredArgsConstructor
@Repository
public class BoardRepository {
    private final EntityManager em;

    @Transactional
    public void save(Board board){
        em.persist(board);
    }

    public List<Board> findAllV3() {
        String q1 = "select b from Board b order by b.id desc";
        List<Board> boardList = em.createQuery(q1, Board.class).getResultList();

        int[] userIds = boardList.stream().mapToInt(board -> board.getUser().getId()).distinct().toArray();

        String q2 = "select u from User u where u.id in (";
        for (int i = 0; i < userIds.length; i++) {
            if (i == userIds.length - 1) {
                q2 = q2 + userIds[i] + ")";
            } else {
                q2 = q2 + userIds[i] + ",";
            }
        }
        List<User> userList = em.createQuery(q2, User.class).getResultList();

        for (Board board : boardList) {
            for (User user : userList) {
                if (user.getId() == board.getUser().getId()) {
                    board.setUser(user);
                }
            }
        }
        return boardList; // user가 채워져 있어야함.
    }

    public List<Board> findAllV2() {
        Query q1 = em.createQuery("select b from Board b order by b.id desc", Board.class);
        List<Board> boardList = q1.getResultList();

        Set<Integer> userIds = new HashSet<>();
        for (Board board : boardList) {
            userIds.add(board.getUser().getId());
        }

        Query q2 = em.createQuery("select u from User u where u.id in :userIds", User.class);
        q2.setParameter("userIds", userIds);
        List<User> userList = q2.getResultList();

        for (Board board : boardList) {
            for (User user : userList) {
                if (user.getId() == board.getUser().getId()) {
                    board.setUser(user);
                }
            }
        }
        return boardList;
    }

    public List<Board> findAll() { // 다른 정보가 추가로 필요하면 조인하면 됨 - outer join일 때 outer는 생략 가능
        Query query = em.createQuery("select b from Board b order by b.id desc", Board.class);
        return query.getResultList();
    }

    public Board findByIdJoinUser(int id) { // on생략 가능, 알아서 pk연결해줌
        Query query = em.createQuery("select b from Board b join fetch b.user u where b.id = :id", Board.class);
        query.setParameter("id", id);
        return (Board) query.getSingleResult();
    }

    public Board findById(int id) {
        //id, title, content, user_id(이질감), created_at
        Board board = em.find(Board.class, id);
        return board;
    }
}

4. BoardController 에 save 수정하

package shop.mtcoding.blog.board;

import ch.qos.logback.core.model.Model;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpSession;
import jakarta.transaction.Transactional;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import shop.mtcoding.blog.user.User;

import java.lang.annotation.Native;
import java.util.List;

@RequiredArgsConstructor
@Controller
public class BoardController {

    private final BoardRepository boardRepository;
    private final HttpSession session;

    // @Transactional 트랜잭션 시간이 너무 길어져서 service에 넣어야함
    @PostMapping("/board/{id}/update")
    public String update(@PathVariable Integer id) {
        return "redirect:/board/" + id;
    }

    @GetMapping("/board/{id}/update-form")
    public String updateForm(@PathVariable(name = "id") Integer id, HttpServletRequest request) {
        return "/board/update-form"; // 서버가 내부적으로 index를 요청 - 외부에서는 다이렉트 접근이 안됨
    }

    @PostMapping("/board/{id}/delete")
    public String delete(@PathVariable Integer id) { // DTO 없이 구현
        return "redirect:/";
    }

    @GetMapping("/")
    public String index(HttpServletRequest request) {
        List<Board> boardList = boardRepository.findAll();
        request.setAttribute("boardList", boardList);
        return "index"; // 서버가 내부적으로 index를 요청 - 외부에서는 다이렉트 접근이 안됨
    }

    @PostMapping("/board/save")
    public String save(BoardRequest.SaveDTO reqDTO) {
        User sessionUser = (User) session.getAttribute("sessionUser");
        boardRepository.save(reqDTO.toEntity(sessionUser));
        return "redirect:/";
    }

    @GetMapping("/board/save-form")
    public String saveForm() {
        return "board/save-form";
    }

    @GetMapping("/board/{id}")
    public String detail(@PathVariable Integer id, HttpServletRequest request) { // Integer : 없으면 null, int : 0
        Board board = boardRepository.findByIdJoinUser(id);
        request.setAttribute("board", board);
        return "board/detail";
    }
}