OneToOne 用户 Jhipster 关系

Question

I have created a UserExtra entity with OneToOne relationship to User entity like this

User.java

public class User extends AbstractAuditingEntity implements Serializable {

...

@OneToOne(mappedBy = "user")
    @JsonIgnoreProperties(value = "user")
    private UserExtra userExtra;

UserExtra.java

public class UserExtra extends AbstractAuditingEntity implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    private Long id;

    @MapsId
    @JoinColumn(name = "id")
    @JsonIgnore
    private User user;
    ...

}

But, when I search a user on terminal appears this error:

SLF4J: Failed toString() invocation on an object of type [org.springframework.http.ResponseEntity]
Reported exception:
java.lang.StackOverflowError
    at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:449)
    at java.lang.StringBuilder.append(StringBuilder.java:136)
    at co.interedes.domain.UserExtra.toString(UserExtra.java:91)
    at java.lang.String.valueOf(String.java:2994)

Answer 1

This is, probably, because you have a circular reference in your toString() methods. This means User prints UserExtra , and UserExtra prints User entering a never ending loop.

One way to fix this is to simply remove the User from the toString() method inside UserExtra or have it print only the User ID instead of the whole object.