小编Vin*_*raj的帖子

我试图建立JPA与第一次用这个测试项目中的Hibernate实现.遇到以下错误:

Exception in thread "main" javax.persistence.PersistenceException: [PersistenceUnit: ExamModulePu] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:924)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:899)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:59)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47)
at service.tests.ExamServiceTest.main(ExamServiceTest.java:18)
Caused by: org.hibernate.AnnotationException: @OneToOne or @ManyToOne on entities.Question.examId references an unknown entity: long
at org.hibernate.cfg.ToOneFkSecondPass.doSecondPass(ToOneFkSecondPass.java:109)
at org.hibernate.cfg.Configuration.processEndOfQueue(Configuration.java:1536)
at org.hibernate.cfg.Configuration.processFkSecondPassInOrder(Configuration.java:1457)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1365)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1756)
at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:96)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:914)

这些是我的实体:

@Entity
public class Exam implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private String name;
    private int numQuestions;
    private int minutesAllotted;
    private Date startDate;
    private Date …