Question

我正在开发一个使用Hibernate和MySQL的项目。在我的一个模型对象中，我声明了一个类型为Blob的属性“image”，我使用了com.mysql.jdbc.Blob。但是当我运行该程序时，发生了一个错误：org.hibernate.MappingException：无法确定：com.mysql.jdbc.Blob的类型，在表：SPOT，对于列：[org.hibernate.mapping.Column（image） ]。以下是数据模型的源代码：

    @Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "SPOT", catalog = "ar", uniqueConstraints = @UniqueConstraint(columnNames = "name"))
@XmlRootElement(name = "spot")
public class Spot extends BaseIdObject {
    private Double axisX;
    private Double axisY;
    private String address;
    private String spotType;
    private String description;
    private String phoneNumber;
    private String website;
    private Blob image;

    @Column(name = "axis_x", precision = 22, scale = 0)
    @NotNull
    public Double getAxisX() {
        return this.axisX;
    }

    public void setAxisX(Double axisX) {
        this.axisX = axisX;
    }

    @Column(name = "axis_y", precision = 22, scale = 0)
    @NotNull
    public Double getAxisY() {
        return this.axisY;
    }

    public void setAxisY(Double axisY) {
        this.axisY = axisY;
    }

    @Column(name = "address", length = 200)
    @NotNull
    public String getAddress() {
        return this.address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Column(name = "spot_type", length = 50)
    @NotNull
    public String getSpotType() {
        return this.spotType;
    }

    public void setSpotType(String spotType) {
        this.spotType = spotType;
    }

    @Column(name = "description", length = 2000)
    public String getDescription() {
        return this.description;
}

public void setDescription(String description) {
    this.description = description;
}

@Column(name = "phone_number", length = 30)
public String getPhoneNumber() {
    return this.phoneNumber;
}

public void setPhoneNumber(String phoneNumber) {
    this.phoneNumber = phoneNumber;
}
}

这是表SPOT的相应DDL：

DROP TABLE IF EXISTS `spot`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `spot` (
  `ID` int(11) NOT NULL AUTO_INCREMENT,
  `NAME` varchar(200) DEFAULT NULL,
  `AXIS_X` double NOT NULL,
  `AXIS_Y` double NOT NULL,
  `ADDRESS` varchar(200) DEFAULT NULL,
  `SPOT_TYPE` varchar(50) NOT NULL,
  `DESCRIPTION` varchar(2000) DEFAULT NULL,
  `PHONE_NUMBER` varchar(30) DEFAULT NULL,
  `WEBSITE` varchar(200) DEFAULT NULL,
  `IMAGE` blob,
  PRIMARY KEY (`ID`),
  UNIQUE KEY `SPOT_ID_UNIQUE` (`ID`),
  UNIQUE KEY `SPOT_NAME_UNIQUE` (`NAME`)
) ENGINE=InnoDB AUTO_INCREMENT=27 DEFAULT CHARSET=utf8;
/*!40101 SET character_set_client = @saved_cs_client */;

我在互联网上搜索并发现了使用java.sql.Blob的建议。但是当我改为那种类型时，发生了另一个错误，因为在我的程序中，我在该模型对象上使用XML做了一些进程，所以它无法处理接口java.sql.Blob。那么我要做的是保持数据类型com.mysql.jdbc.Blob并且程序仍然可以正常运行Hibernate？非常感谢你。

Answer 1

我要说依赖JDBC驱动程序的实现细节是不对的。我会检查你的依赖，并尝试使它成为一个软依赖。如果你真的需要保持这种强硬依赖关系，那么你需要实现一个能够处理UserType的{{1}}。我不知道有关此实现的详细信息，但您可以将Hibernate的BlobType扩展为MySQLBlobType，并使用com.mysql.jdbc.Blob注释注释您的模型属性，并指定此@Type：

https://github.com/hibernate/hibernate-core/blob/master/hibernate-core/src/main/java/org/hibernate/type/BlobType.java

https://github.com/hibernate/hibernate-core/blob/master/hibernate-core/src/test/java/org/hibernate/test/annotations/type/Dvd.java

Hibernate错误：无法确定：com.mysql.jdbc.Blob的类型

1 个答案: