本文介绍了JPA Embeddable类可以包含对象引用吗?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试将一个类嵌入另一个包含对象引用的类.我总是得到
I'm trying to embed a class to another which contains object reference. I always get
org.hibernate.MappingException: Could not determine type for: ...
例外.我的问题是,有什么方法可以嵌入包含对象引用的类,或者可嵌入的类仅存储基元.
exception. My question is there any way I can embed a class which contains object references, or embeddable classes only stores primitives.
我已经尝试过@Target()注解,但没有帮助.
I'm already tried @Target() annotation but not helps.
推荐答案
是的,这是可能的.查看文档. /p>
Yes, this is possible. Look at the documentation.
@Embeddable
public static class Publisher {
private String name;
@ManyToOne(fetch = FetchType.LAZY)
private Country country;
//Getters and setters, equals and hashCode methods omitted for brevity
}
@Entity(name = "Book")
@AttributeOverrides({
@AttributeOverride(
name = "ebookPublisher.name",
column = @Column(name = "ebook_publisher_name")
),
@AttributeOverride(
name = "paperBackPublisher.name",
column = @Column(name = "paper_back_publisher_name")
)
})
@AssociationOverrides({
@AssociationOverride(
name = "ebookPublisher.country",
joinColumns = @JoinColumn(name = "ebook_publisher_country_id")
),
@AssociationOverride(
name = "paperBackPublisher.country",
joinColumns = @JoinColumn(name = "paper_back_publisher_country_id")
)
})
public static class Book {
@Id
@GeneratedValue
private Long id;
private Publisher ebookPublisher;
private Publisher paperBackPublisher;
//Getters and setters are omitted for brevity
}
这篇关于JPA Embeddable类可以包含对象引用吗?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!