46. 응답 DTO - 글 목록 조회 만들기v7

1. 글 목록조회

• 필요한 정보 : id, title

2.BoardResponse 에 MainDTO 만들기

package shop.mtcoding.blog.board;

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

public class BoardResponse {

    @Data
    public static class MainDTO {
        private Integer id;
        private String title;

        public MainDTO(Board board) {
            this.id = board.getId();
            this.title = board.getTitle();
        }
    }
}

3. BoardService 에 findAll() 수정하기

package shop.mtcoding.blog.board;

import lombok.RequiredArgsConstructor;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import shop.mtcoding.blog._core.errors.exception.Exception403;
import shop.mtcoding.blog._core.errors.exception.Exception404;
import shop.mtcoding.blog.user.User;

import java.util.List;

@RequiredArgsConstructor
@Service
public class BoardService {

    private final BoardJPARepository boardJPARepository;

    public List<BoardResponse.MainDTO> findAll() { // 글목록조회
        Sort sort = Sort.by(Sort.Direction.DESC, "id");
        List<Board> boardList = boardJPARepository.findAll(sort);
        return boardList.stream().map(board -> new BoardResponse.MainDTO(board)).toList();
			  // return boardList.stream().map(BoardResponse.MainDTO::new).toList();와 같은 것
    }
}

4. BoardController 에 main 수정하기

package shop.mtcoding.blog.board;

import jakarta.servlet.http.HttpSession;
import lombok.RequiredArgsConstructor;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import shop.mtcoding.blog._core.utils.ApiUtil;
import shop.mtcoding.blog.user.User;

import java.util.List;

@RequiredArgsConstructor
@RestController
public class BoardController {

    private final HttpSession session;
    private final BoardService boardService;

    @GetMapping("/")
    public ResponseEntity<?> main() {
       List<BoardResponse.MainDTO> respDTO = boardService.findAll();
        return ResponseEntity.ok(respDTO); // board에 연관된 객체가 있기에 위험함 / 무한 참조가 일어날 수 있음
    }
   }