Question

我正在尝试从数据库中读取byte[]图像。

这是我的两个实体中的第一个：

@Entity
public class ReceivingInspection implements Serializable {

    /**
     * The id.
     */
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="RECEIVING_INSPECTION_ID")
    private int id;

    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "receivingInspection")
    private List<ReceivingInspectionImage> receivingInspectionImages;

    // Constructors, getters, setters
}

这是我的第二个实体：

@Entity
public class ReceivingInspectionImage implements Serializable {

    @EJB
    private ImageService imageService;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="RECEIVING_INSPECTION_IMAGE_ID")
    private int id;

    @Lob @Basic(fetch = FetchType.LAZY)
    @Column(length=16777000)
    private byte[] image;

    @ManyToOne(fetch = FetchType.LAZY)
    private ReceivingInspection receivingInspection;

    public byte[] getImage() {
        return imageService.getImage(id);
    }

    // Constructors, getters, setters
}

这是我的DAO：

@PersistenceContext
private EntityManager em;

public byte[] getImage(int id) {
    Query query = em
            .createNativeQuery("SELECT * FROM RECEIVINGINSPECTIONIMAGE WHERE RECEIVING_INSPECTION_IMAGE_ID = ?");
    query.setParameter(1, id);
    ReceivingInspectionImage image = (ReceivingInspectionImage) query.getSingleResult();
    return image.getImage();
}

当我尝试部署我的应用程序时，我得到了一个：

org.hibernate.MappingException：无法确定：my.application.util.ImageService的类型，在表：ReceivingInspectionImage，对于列：[org.hibernate.mapping.Column（imageService）]“}}

什么可能导致问题？我使用Hibernate映射的方式有错吗？

Answer 1

问题出在这里

@EJB
private ImageService imageService;

您不应在Entity内注入服务，Hibernate会尝试将其映射到列。

不应该从DAO调用

Entity图层，创建与DAO互动的服务。

org.hibernate.MappingException：无法确定列的类型：[org.hibernate.mapping.Column（imageService）]“}}

1 个答案: