인프런 커뮤니티 질문&답변

배운것을 바탕으로 개인적으로 게시판을 만들어보는 중입니다. 게시물을 추가할 때 다음과 같은 에러가 발생해서 몇시간째 애를 먹고있는 중입니다.

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.myproject.jpaboard.domain.Member.posts: could not initialize proxy - no Session

아무래도 Post(게시물) 엔티티의 연관관계 편의 메서드에서 문제가 발생하는 것 같습니다. 서비스 계층에 @Transactional도 붙여줬음에도 계속해서 문제가 발생해서 질문 남깁니다. 유일한 해결책은 Member의 posts에 EAGER을 붙이는 방법이었습니다. 하지만 이는 적절치 않아보입니다. 어떻게 해야 해결할 수 있을까요.

핵심이 되는 코드들을 아래에 추가했습니다.

package com.myproject.jpaboard.web.controller;

import com.myproject.jpaboard.domain.Member;
import com.myproject.jpaboard.domain.Post;
import com.myproject.jpaboard.web.SessionConst;
import com.myproject.jpaboard.web.form.PostForm;
import com.myproject.jpaboard.web.repository.BoardRepository;
import com.myproject.jpaboard.web.service.BoardService;
import com.myproject.jpaboard.web.service.PostService;
import jakarta.servlet.http.HttpServletRequest;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

@Controller
@RequestMapping("/post")
@RequiredArgsConstructor
@Slf4j
public class PostController {

    private final BoardService boardService;
    private final BoardRepository boardRepository;
    private final PostService postService;

  

    /**
     * 게시물 추가
     */
    @PostMapping("/new")
    public String addPost(@SessionAttribute(name = SessionConst.LOGIN_MEMBER, required = false) Member loginMember, @Validated PostForm postForm, BindingResult bindingResult) {

        log.info("postForm={}", postForm);

        if (bindingResult.hasErrors()) {
            log.info("errors={}", bindingResult);
            return "newPost";
        }
        postService.addPost(postForm, loginMember);

        return "redirect:/board/list";
    }

  
}


// Post.java
@Entity
@Getter @Setter
public class Post {

    @Id
    @GeneratedValue
    @Column(name = "post_id")
    private Long id;

    private String title;
    private String writer;

    @Lob
    @Column(columnDefinition="LONGTEXT")
    private String content;

    @Column(updatable = false)
    private LocalDateTime createdTime;
    private LocalDateTime lastModifiedTime;
    private Long viewCount;

    @ManyToOne(fetch = FetchType.LAZY) // 다쪽이 연관관계의 주인
    @JoinColumn(name = "member_id")
    private Member member;

    @Enumerated(EnumType.STRING)
    private CategoryType category;

    @OneToMany(mappedBy = "post", cascade = CascadeType.ALL, orphanRemoval = true)
    private List<Comment> comments = new ArrayList<>();

    public Post() {}

    // 연관관계 편의 메서드
    public void setMember(Member member) {
        this.member = member;
        member.getPosts().add(this);
    }

    @Override
    public String toString() {
        return "Post{" +
                "id=" + id +
                ", title='" + title + '\'' +
                ", writer='" + writer + '\'' +
                ", content='" + content + '\'' +
                ", createdTime=" + createdTime +
                ", lastModifiedTime=" + lastModifiedTime +
                ", viewCount=" + viewCount +
                ", category=" + category +
                '}';
    }
}

// Member.java
@Entity
@Getter @Setter
public class Member {

    @Id
    @GeneratedValue
    @Column(name = "member_id")
    private Long id;

    private String email;
    private String password;

    private String name;

    @Embedded
    private Address address;

    @OneToMany(mappedBy = "member", cascade = CascadeType.ALL)
    private List<Post> posts = new ArrayList<>();


    /**
     * POST 추가 로직 (도메인 모델 패턴)
     */
//    public void addPost(Post post) {
//
//
//    }


    @Override
    public String toString() {
        return "Member{" +
                "address=" + address +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                ", id=" + id +
                '}';
    }
}

// PostService.java
@Service
@RequiredArgsConstructor
@Transactional(readOnly = true)
public class PostService {

    private final BoardRepository boardRepository;
    private final PostRepository postRepository;

    /**
     * 게시물 추가
     */
    @Transactional
    public void addPost(PostForm postForm, Member loginMember) {

        Post post = new Post();
        postForm.setCreatedTime(LocalDateTime.now());

        // setter로 세팅
        post.setTitle(postForm.getTitle());
        post.setWriter(postForm.getWriter());
        post.setContent(postForm.getContent());
        post.setCreatedTime(postForm.getCreatedTime());
        post.setCategory(postForm.getCategory());
        post.setViewCount(0L);
        post.setWriter(loginMember.getName());

        post.setMember(loginMember);
        postRepository.save(post);
    }
}