spring - 具有一对多关系的 Spring Boot 的无限循环

Question

在休息应用程序中，我使用带有 jpa 的 spring boot。

我有一个类房客

谁有

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "lodger")
private List<Reference> referenceList;

在我的课引用中，我有

@ManyToOne
@JoinColumn(name = "lodgerId")
private Lodger lodger;

当我调用这个方法时

@RequestMapping(value = "/lodgers/{lodgerId}", method = RequestMethod.GET)
public Lodger getLogderById(@PathVariable("lodgerId") long lodgerId) {
    return lodgerService.getLodger(lodgerId);
}

我收到这个错误

org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: Infinite recursion (StackOverflowError) (through reference chain: server.bean.Lodger["referenceList"]->org.hibernate.collection.internal.PersistentBag[0]->server.bean.Reference["lodger"]->server.bean.Lodger["referenceList"]->org.hibernate.collection.internal.PersistentBag[0]->server.bean.Reference["lodger"]->server.bean.Lodger["referenceList"]...

Answer 1

解决方案:

用
@JsonManagedReference实例化的第一个对象的注释
@JsonBackReference实例化的第二个对象的注释

第一的:

@JsonManagedReference
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "lodger")
    private List<Reference> referenceList;

第二:

@JsonBackReference
@ManyToOne
    @JoinColumn(name = "lodgerId")
    private Lodger lodger;