Question

我有一个基础抽象类。

@Entity
@Table(name = "P_FLD")
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "FLD_DISCRIMINATOR", columnDefinition = "CHAR(3)")
abstract public class AbstractPassbookField

和一些扩展它的类。例如：

@Entity
@DiscriminatorValue("F")
@Table(name = "P_FLD_F")
public class PassbookFileField extends AbstractPassbookField

我为基础实体创建存储库

public interface PassbookRepository extends CrudRepository<AbstractPassbookField, Long>

我正在进行下一次测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:test-config.xml")
public class PassbookFieldRepositoryTest {

    @Autowired
    PassbookRepository passbookRepository;

    @PersistenceContext
    private EntityManager em;

    @Test
    public void testSave() {
        PassbookFileField passbookFileField = new PassbookFileField();
        passbookFileField.setFilename("text.test");
        passbookFileField.setTemplate(true);
        passbookFileField.setReadonly(true);
        passbookFileField.setImageType(ImageType.I);
        passbookFileField.setResoltuionType(ImageResolutionType.N);

        passbookFileField = passbookRepository.save(passbookFileField);

        passbookRepository.findAll();
    }
}

passbookRepository.save（passbookFileField） - 效果很好，但是 passbookRepository.findAll（）给了我一个例外

org.springframework.orm.hibernate3.HibernateObjectRetrievalFailureException: Object [id=1] was not of the specified subclass [ru.teamlabs.moneybox.commons.model.passbook.field.AbstractPassbookField] : Discriminator: F ; nested exception is org.hibernate.WrongClassException: Object [id=1] was not of the specified subclass [ru.teamlabs.moneybox.commons.model.passbook.field.AbstractPassbookField] : Discriminator: F

通过entityManager查询给出了同样的错误。我做错了什么？

Answer 1

您还没有为超级类提供DiscriminatorValue值，因此在检索它时无法区分超类和子类。尝试以下，它必须工作。

@Entity
@Table(name = "P_FLD")
@DiscriminatorValue("SF")
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "FLD_DISCRIMINATOR", columnDefinition = "CHAR(3)")
abstract public class AbstractPassbookField

Answer 2

我发现了它为什么会发生。

@DiscriminatorColumn(name = "FLD_DISCRIMINATOR", columnDefinition = "CHAR(3)")

这个字符串就是问题所在。

在PassbookFileField中我有

@DiscriminatorValue("F")

但是，存储库期望获得带有3个字符的鉴别器的实体。

这种鉴别者

@DiscriminatorValue("F")

或此类鉴别器列定义

@DiscriminatorColumn(name = "FLD_DISCRIMINATOR", columnDefinition = "CHARACTER VARYING(3)")

解决问题

弹簧数据中的多态查询

2 个答案: