Spring Data JPA @OneToOne注释无限递归错误
package com.example.demo.com.example.domain;import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.NoArgsConstructor;
import lombok.ToString;
import javax.persistence.*;
//@Data
//@NoArgsConstructor
//@EqualsAndHashCode
//@ToString
@Entity
@Table(name = "t_husban")
public class Husband {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;
private String job;
@OneToOne
@JoinColumn(name = "wife_fk",referencedColumnName = "id")
private Wife wife;
//omitted getter/setter
}
package com.example.demo.com.example.domain;import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.NoArgsConstructor;
import lombok.ToString;
import javax.persistence.*;
//@Data
//@NoArgsConstructor
@EqualsAndHashCode(exclude = "husband",callSuper = false)
@Entity
@Table(name = "t_wife")
public class Wife {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;
@OneToOne(mappedBy = "wife",cascade = {CascadeType.ALL})
private Husband husband;
//omitted getter/setter
}
@Service public class TestOneToOneEitherSide {
@Autowired
private WifeRepository wifeDao;
@Autowired
private HusbandRepository husbandDao;
public Husband testCreate() {
Husband husband = husbandDao.findByName("Wang");
return husband;
}
}
当我使用spring数据jpa从数据库中查询丈夫时,结果发生无限递归,参见下图。使用@OneToOne注释时出了什么问题?有人可以给我一些建议吗?或者我以错误的方式使用了注释。
图片
回答:
这是一个已知问题,当您具有双向关系时,杰克逊将尝试从另一侧序列化一侧的每个引用,以便逻辑上具有无限递归。
解决方案:有很多解决方案,可以在一侧使用@JsonIgnore以避免序列化带注释的引用,从而破坏了无限递归
@EqualsAndHashCode(exclude = "husband",callSuper = false) @Entity
@Table(name = "t_wife")
public class Wife {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;
@OneToOne(mappedBy = "wife",cascade = {CascadeType.ALL})
@JsonIgnore
private Husband husband;
//omitted getter/setter
}
您也可以使用@ JsonManagedReference / @
JsonBackReference,请查看此链接以获取更多有关如何使用它们的信息
这个答案有一个问题,如果您尝试序列化妻子的方向,您将没有丈夫对象,因为解决方案是避免序列化它。
有一个很好的解决方案,它在此链接中提到,其思想是生成对父实体的引用,因此,如果您要序列化丈夫,您将拥有丈夫->妻子-> [引用丈夫而不是丈夫]
,您所需要做的就是使用@JsonIdentityInfo注释您的实体
@EqualsAndHashCode(exclude = "husband",callSuper = false)@Entity
@Table(name = "t_wife")
@JsonIdentityInfo(generator=ObjectIdGenerators.UUIDGenerator.class, property="@id")
public class Wife {
@JsonIdentityInfo(generator=ObjectIdGenerators.UUIDGenerator.class, property="@id")
@Entity
@Table(name = "t_husban")
public class Husband {
@Id
以上是 Spring Data JPA @OneToOne注释无限递归错误 的全部内容, 来源链接: utcz.com/qa/413500.html