我有2个实体类，名为Post和Post详细信息。两者都使用MapsId与OneToOne关系映射，并共享主键，如下所示。

Post.java

@Entity
@Table(name = "post")
@Data
public class Post implements Serializable
{
    private static final long serialVersionUID = -6698422774799518217L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NaturalId
    @Column(name = "title")
    private String title;

    @OneToOne(mappedBy = "post", cascade = CascadeType.ALL, fetch = FetchType.LAZY, optional = false)
    private PostDetail detail;

}

PostDetail.java

@Entity
@Table(name = "post_detail")
@Data
public class PostDetail implements Serializable
{
    private static final long serialVersionUID = -6699482774799518217L;

    @Id
    private Long id;

    @Column(name = "created_on")
    private Date createdOn;

    @Column(name = "created_by")
    private String createdBy;

    @OneToOne(fetch = FetchType.LAZY)
    @MapsId
    @JoinColumn(name = "id")
    @JsonIgnore
    private Post post;

}

PostController.java

@RestController
@RequestMapping("/api/v1/post")
public class PostController
{
    private final PostRepository postRepository;

    private final PostDetailRepository postDetailRepository;

    public PostController(PostRepository postRepository, PostDetailRepository postDetailRepository)
    {
        this.postRepository = postRepository;
        this.postDetailRepository = postDetailRepository;
    }

    @GetMapping(path = "/create")
    public List<Post> createAndGetPosts()
    {

        Post post=new Post();
        post.setId(new Random().nextLong());
        post.setTitle("First Post");
        post=postRepository.saveAndFlush(post);

        PostDetail postDetail =new PostDetail();
        postDetail.setCreatedBy("Admin");
        postDetail.setCreatedOn(Date.from(Instant.now()));
        postDetail.setPost(post);
        postDetailRepository.saveAndFlush(postDetail);

        return postRepository.findAll(Sort.by(Sort.Direction.DESC,"id"));
    }


}

在Post Controller类中，我创建Post对象（保存DB），然后将其传递给PostDetail对象，然后使用Spring Data JPA将其保存到数据库中。一切都按预期工作。但是当我立即获取记录列表时，通过postReposity. findAll（Sort.by（Sort.Direction.DESC，"id"））；方法，我在Post中接收PostDetail对象的null值，如下所示。

回应：

[
  {
    "id": 2,
    "title": "First Post",
    "detail": null
  },
  {
    "id": 1,
    "title": "Post1",
    "detail": {
      "id": 1,
      "createdOn": "2019-06-21T03:31:43.000+0000",
      "createdBy": "Admin"
    }
  }
]

但是当我再次从列表前端发送请求时，我得到了适当的响应。我尝试将flush语句和第二个findAll（）语句放在请求之前，没有任何效果。