EclipseLink描述符定制器和历史策略以及JSF.如何在历史记录中插入用户主体？

@Entity
@Table(name = "user")
@Customizer(UserCustomizer.class)
@History(strategy = HistoryStrategyType.TIMESTAMP)
public class User {
    @Id
    private Long id;
    private String name;
    private String email;
    @Temporal(TemporalType.TIMESTAMP)
    private Date createdDate;
    @Temporal(TemporalType.TIMESTAMP)
    private Date updatedDate;
    // getters and setters
}

public class UserService {
    private EntityManagerFactory emf;
    private EntityManager em;

    public UserService() {
        emf = Persistence.createEntityManagerFactory("my-pu");
        em = emf.createEntityManager();
    }

    public void saveUser(User user) {
        em.getTransaction().begin();
        em.persist(user);
        em.getTransaction().commit();
    }

    public List<User> getUserHistory(Long userId) {
        Query query = em.createQuery("SELECT u FROM UserHistory u WHERE u.id = :userId ORDER BY u.createdDate DESC");
        query.setParameter("userId", userId);
        return query.getResultList();
    }
}