休眠onetomany多音问题

Question

我正在使用休眠作为ORM。 我有两个实体Shop和TypeShop 。 TypeShop可能有一些商店。

@Entity
@Table(name = "shop_types")
public class TypeShop {
    ...
    @OneToMany(fetch = FetchType.EAGER, mappedBy="typeShop", cascade = CascadeType.ALL)
    private Set<Shop> shops;
    ...
}

和

@Entity
@Table(name = "shops")
public class Shop {
    ...
    @ManyToOne(fetch=FetchType.EAGER)
    @JoinColumn(name = "shop_type_id")
    private TypeShop typeShop;
    ...
}

当我想通过json格式的TypeShop id查找所有shops ，我得到如下信息：

[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First Description","coordinates":"59.842055288480076, 29.700164794921875","contacts":"First Contacts","site":"First web site","mail":"First email","photos":[],"typeShop":{"id":11,"name":"Производство газобетона","shops":[{"id":146,"name":"First Name","address":"First Address","description":"First .....

列表一次又一次地继续下去。 如您所见，由于获取类型为EAGER我得到了无限的json格式。 我曾尝试将EAGER更改为LAZY但出现“failed to lazily initialize a collection of role” exception 。

我怎么解决这个问题？ 提前致谢！

编辑：如果我从Shop实体中删除TypeShop吸气剂，则有帮助。 但是我很好奇是否有更好的方法。

Answer 1

这称为JSON双向引用问题。 引用： http ://wiki.fasterxml.com/JacksonFeatureBiDirReferences

检查@JsonIdentityInfo和@ JsonBackReference / @ JsonManagedReference

用注释您的实体

@JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="@id")

应该可以解决您的问题。