多个反向引用属性，名称为“defaultReference” [英] Multiple back-reference properties with name 'defaultReference'

问题描述

我在一个类中有多个反向引用类。由于我使用 @JsonBackReference ，我收到错误。我为这些类分配了 @JsonIdentityInfo 注释，但我仍然得到同样的错误。

I have multiple back-reference classes in a class. Since I use @JsonBackReference for them, I get an error. I assigned @JsonIdentityInfo annotation for those classes, but I still get the same error.

public class X implements Serializable {
  ....
  //bi-directional many-to-one association to Booking
  @ManyToOne(fetch = FetchType.EAGER)
  @JoinColumn(name = "xxA", nullable = false)
  @JsonBackReference
  private A a;

  //bi-directional many-to-one association to Client
  @ManyToOne(fetch = FetchType.EAGER)
  @JoinColumn(name = "xxB", nullable = false)
  @JsonBackReference
  private B b;
  ...getters setters
}

@JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, property = "@id")
public class B implements Serializable {
  ........ 
  //bi-directional many-to-one association to BookedClient
  @OneToMany(mappedBy = "b", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
  @JsonManagedReference
  private List < X > xxB;
  ........ getters setters
}


@JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, property = "@id")
public class A implements Serializable {
  ........
  //bi-directional many-to-one association to BookedClient
  @OneToMany(mappedBy = "a", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
  @JsonManagedReference
  private List < X > xxA;
  ........ getters setters
}

错误：

com.fasterxml.jackson.databind.JsonMappingException：名称为'defaultReference'的多个反向引用属性

com.fasterxml.jackson.databind.JsonMappingException: Multiple back-reference properties with name 'defaultReference'

如何解决此错误？我可以不在课堂上使用多个反向引用吗？

How can I resolve this error? Can I not use multiple back-reference in a class?

推荐答案

根据 Jackson的javadoc ， @JsonManagedReference 和 @ JsonBackReference 接受将它们绑定在一起的名称值：

According to Jackson's javadoc, both @JsonManagedReference and @JsonBackReference accept a name value that binds them together:

  @JsonBackReference("a")
  private A a;

  @JsonManagedReference("a")
  private List < X > xxA;

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