杰克逊映射无限递归。春季数据休息

Question

我的项目设置是 Spring Boot 1.3.1.RELEASE、Spring Data Rest。

我有一个实体如下

@Entity
public class Criteria extends BaseEntity {
    @OneToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "CRITERIA__GROUP", joinColumns = @JoinColumn(name = "CRITERIA__ID"), inverseJoinColumns = @JoinColumn(name = "GROUP__ID"))
    private Set<Group> planningCriteriaGroup = new HashSet<Group>();
}

@Entity
public class Group extends BaseEntity {
    @OneToMany(fetch = FetchType.EAGER, cascade = {CascadeType.MERGE, CascadeType.REFRESH, CascadeType.DETACH, CascadeType.PERSIST})
    @JoinColumn(name = "GROUP__ID")
    private Set<Category> categories = new HashSet<Category>(0);
}

@Entity
public class Category extends BaseEntity {
    @ManyToOne(fetch = FetchType.EAGER)
    @JsonBackReference
    private Category parent;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "parent", fetch = FetchType.EAGER, orphanRemoval = true)
    @Fetch(value = FetchMode.JOIN)
    @JsonManagedReference
    private Set<Category> children = new HashSet<Category>(0);
} 

当我卷曲以获取标准时

curl -v -X GET -H "Content-Type: application/json" "http://localhost:8080/criterias"

抛出以下错误 -

{"timestamp":1452510716889,"status":500,"error":"内部服务器错误","exception":"org.springframework.http.converter.HttpMessageNotWritableException","message":"无法写入内容：无限递归（StackOverflowError）（通过引用链：org.springframework.hateoas.PagedResources[\"_embedded\"]）；嵌套异常为com.fasterxml.jackson.databind.JsonMappingException：无限递归(StackOverflowError)（通过引用链: org.springframework.hateoas.PagedResources[\"_embedded\"])","path":"/criterias"}

@JsonBackReference 和@JsonManagedReference 似乎并不能解决无限递归的问题。

Answer 1

您可以在父级处使用@JsonIgnore。