[스프링부트] 익명블로그 만들어보기 V2

CRUD JPA를 사용하여 리팩토링

Controller

import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.List;
@Controller
@RequiredArgsConstructor
public class BoardController {

    private final BoardService boardService;


    @GetMapping("/")
    public String list(Model model) { 
        List<BoardResponse.DTO> boardList = boardService.게시글목록보기();
        model.addAttribute("models", boardList);

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

    @GetMapping("/board/{id}/update")
    public String updateForm(@PathVariable int id, Model model) {
        model.addAttribute("model",boardService.게시글수정화면보기(id));
        return "update-form";
    }

    @GetMapping("/board/{id}")
    public String detail(@PathVariable("id") int id, Model model) {
        model.addAttribute("model",boardService.게시글상세보기(id));
        return "detail";
    }

    @PostMapping("/board/save")
    public String saveV2(BoardRequest.SaveDTO saveDTO) {
        boardService.게시글쓰기(saveDTO);
        return "redirect:/";
    }

    @PostMapping("/board/{id}/delete")
    public String delete(@PathVariable("id") int id) {
        boardService.게시글삭제(id);
        return "redirect:/";
    }
    @PostMapping("/board/{id}/update")
    public String update(@PathVariable("id") int id, BoardRequest.updateDTO updateDTO) {
        boardService.게시글수정(id,updateDTO);
        return "redirect:/";
    }

}

Service

• Stream을 이용한 게시글 목록보기 리팩토링

import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

// Service의 책임 : 비지니스 로직 처리(트렌젝션 관리), DTO
@Service
@RequiredArgsConstructor
public class BoardService {

    private final BoartRepository boardRepository;

    public List<BoardResponse.DTO> 게시글목록보기(){

        return boardRepository.findAll().stream()
                .map(BoardResponse.DTO::new)
                .toList();
    };
    public BoardResponse.updateFormDTO 게시글수정화면보기(int id) {
        return new BoardResponse.updateFormDTO(boardRepository.findById(id).orElseThrow(() ->new RuntimeException("해당 ID의 게시글이 없습니다." + id)));
    }

    public BoardResponse.DetailDTO 게시글상세보기(int id) {
        return new BoardResponse.DetailDTO(boardRepository.findById(id).orElseThrow(() ->new RuntimeException("해당 ID의 게시글이 없습니다." + id)));
    }

    @Transactional
    public void 게시글쓰기(BoardRequest.SaveDTO saveDTO) {
        boardRepository.save(saveDTO.toEntity());
    }

    @Transactional
    public void 게시글삭제(int id) {
        boardRepository.delete(id);
    }

    @Transactional
    public void 게시글수정(int id, BoardRequest.updateDTO updateDTO) {
        Board board =boardRepository.findById(id).orElseThrow(() ->new RuntimeException("해당 ID의 게시글이 없습니다." + id));
        board.update(updateDTO.getTitle(), updateDTO.getContent());
    } // 영속화된 객체 상태 변화 - update+commit => 더티체킹
}

Repository

• JPQL을 활용한 Repository 리팩토링

import jakarta.persistence.EntityManager;
import jakarta.persistence.Query;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Repository;

import java.util.List;
import java.util.Optional;

@Repository
@RequiredArgsConstructor
public class BoartRepository {

    private final EntityManager em;

    public List<Board> findAll() {
       return em.createQuery("select b from Board b order by b.id desc",Board.class).getResultList();
    }
    public Optional<Board> findById(int id) {
        return Optional.ofNullable(em.find(Board.class, id));

    }

    public void save(Board board) {
        // 비영속
        em.persist(board); // 객체를 던지면 insert함
        // 동기화(영속화)
    }

    public void delete(int id){
        em.createQuery("delete from Board b where b.id=:id").setParameter("id", id).executeUpdate();
    }
}