Hibernate: AnnotationException: Unknown MappedBy in ... 反向引用的属性未知 (mappedBy)，双向@OneToOne 关联

Question

我有以下简单的设计:

(来源:kawoolutions.com)
这基本上是 JPA 不支持的非不相交继承的一种解决方法。人员可以单独存在，但可以选择有单个玩家实体、单个教练实体或两个实体来完成逻辑。
这是相当容易理解的 JPA 2.0 映射(注意@Id 前向关联):

@Entity
@Table(name = "Persons")
public class Person implements Serializable
{
    @Id
    @Column(name = "id")
    private Integer id;

    @Column(name = "first_name")
    private String firstName;

    @Column(name = "last_name")
    private String lastName;

    @OneToOne(mappedBy = "person")
    private Coach coach = null;

    @OneToOne(mappedBy = "person")
    private Player player = null;
    
    ...
}

@Entity
@Table(name = "Players")
public class Player implements Serializable
{
    @Column(name = "registration_nbr")
    private String registrationNbr = null;

    @Id
    @OneToOne
    @JoinColumn(name = "id")
    private Person person = null;
    
    ...
}

@Entity
@Table(name = "Coaches")
public class Coach implements Serializable
{
    @Column(name = "license_nbr")
    private String licenseNbr = null;

    @Id
    @OneToOne
    @JoinColumn(name = "id")
    private Person person = null;
    
    ...
}

Player 和 Coach 实体类几乎相同。
这里的问题是两个双向关联(mappedBy)。这些映射与 EclipseLink 完美配合，但 Hibernate 不知何故因 AnnotationException 异常:

Exception in thread "main" javax.persistence.PersistenceException: [PersistenceUnit: persons] Unable to configure EntityManagerFactory
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:374)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:56)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:48)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:32)
    at tld.persons.Main.main(Main.java:32)
Caused by: org.hibernate.AnnotationException: Unknown mappedBy in: tld.persons.model.Person.coach, referenced property unknown: tld.persons.model.Coach.person
    at org.hibernate.cfg.OneToOneSecondPass.doSecondPass(OneToOneSecondPass.java:159)
    at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1686)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1393)
    at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1345)
    at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1477)
    at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:193)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:1096)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:278)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:362)
    ... 4 more

当切换到老式 JPA 1.0 映射时，一切都再次正常运行。 Hibernate 以某种方式似乎对上述映射有问题。
我看过很多其他的问题报告，实际上 hibernate.org 的论坛充满了类似的 Unresolved 问题，但我找不到任何关于为什么会抛出异常的线索。
对我来说，这似乎是一个 Hibernate 错误。有人可以证实这一点吗？ (注意我使用的是 Hibernate 3.6)

Answer 1

如果我们忘记在persistence.xml 中声明实体类，就会遇到这个问题。