自引用记录导致 "Direct self-reference leading to cycle" 异常

Question

我有自引用class

@Entity
@Table(name = "contacts")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
@Document(indexName = "contacts")
public class Contacts implements Serializable
{

private static final long serialVersionUID = 1L;

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

@Column(name = "username")
private String username;

@Column(name = "password_smartlpc")
private String password;

@Column(name = "full_name")
private String fullName;

@ManyToOne
private Contacts companyContact;
}

但是对于我的一个数据库记录

id  full_name   username    password    company_contact_id  
5   JAK movies  abc          xyz               5

这条记录有 company_contact_id 作为其自身 id.Which，而检索进入自引用循环。

Enter: com.fps.web.rest.errors.ExceptionTranslator.processRuntimeException() 
with argument[s] = 
[org.springframework.http.converter.HttpMessageNotWritableException: Could not 
 write content: Direct self-reference leading to cycle (through reference 
 chain: java.util.UnmodifiableRandomAccessList[2]-
 >com.fps.domain.Contacts["companyContact"]-
 >com.fps.domain.Contacts["companyContact"]); nested exception is 
 com.fasterxml.jackson.databind.JsonMappingException: Direct self-reference 
 leading to cycle (through reference chain: 
 java.util.UnmodifiableRandomAccessList[2]-
  >com.fps.domain.Contacts["companyContact"]-
 >com.fps.domain.Contacts["companyContact"])]

变通方法我试过了

(fetch = FetchType.LAZY) = gives same error as above.
@JsonIgnore :  removes error but does not retrieves Company_Contact_id
@JsonManagedReference @JsonBackReference same as above.

不幸的是，我无法更改数据库或更改 it.Since 它的 legacy.Any 更多我可以尝试的东西？？谢谢

Answer 1

在 JHipster 中尝试 using DTOs，您将更好地控制 JSON 序列化，而不是简单地公开您的实体，尤其是当您受到遗留数据库模式的限制时。

自引用记录导致 "Direct self-reference leading to cycle" 异常

Self-Referencing record leading to "Direct self-reference leading to cycle" exception

self-reference

spring-data

spring-data-jpa

spring-boot

jhipster