Java 需要获取l0、l1、l2类别名称

以下是表格结构

类别映射表

需要在Spring中获取l0、l1、l2、l3类别名称的名称

类别实体

@Entity
@Table(name = "category")
@Data
@EqualsAndHashCode(callSuper = false)
public class Category extends BaseEntity {

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

    private Long categoryId;

    private String name;

    private String link;

    private String description;

    @OneToMany
    @JsonManagedReference
    private List<CategoryMapping> mapping;
}

我尝试放置联接注释，但仍然将l0名称字段设置为null

@Entity
@Table(name = "category_mapping")
@Data
@EqualsAndHashCode(callSuper = false)
public class CategoryMapping extends BaseEntity {

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

    private Long l0Category;

    private Long l1Category;

    private Long l2Category;

    private Long l3Category;

    private String link;

    @OneToOne(fetch = FetchType.EAGER)
    @JsonBackReference
    @JoinColumn(name = "category_mapping_l0Category")
    private Category l0;

    private String description;

    private boolean isVerified;
}