Java Spring数据：如何在使用@Embeddeble和@Embedded时设置GenerationType策略

我试图在Spring数据中使用

@Embedded

和

@Embedded

。下面是我的方法

设备实体：

@Entity
@Table(name = "device")
public class DeviceEntity implements Serializable {


      private static final long serialVersionUID = 1L;

      @EmbeddedId
      @AttributeOverrides({@AttributeOverride(name = "id" , column= @Column(name = "id",nullable = false))})
      private DeviceIdType deviceIdType;

.

@Embeddable
public class DeviceIdType implements Serializable {

  private static final long serialVersionUID = 1L;

  @Column(name = "id")
  @GeneratedValue(strategy = GenerationType.AUTO)
  private long id;

"code": "4715",
  "message": "Something went wrong",
  "additionalInfo": "null id generated for:class com.b.DeviceEntity; nested exception is org.hibernate.id.IdentifierGenerationException: null id generated for:class com.b.DeviceEntity"

设备类型：

@Entity
@Table(name = "device")
public class DeviceEntity implements Serializable {


      private static final long serialVersionUID = 1L;

      @EmbeddedId
      @AttributeOverrides({@AttributeOverride(name = "id" , column= @Column(name = "id",nullable = false))})
      private DeviceIdType deviceIdType;

.

@Embeddable
public class DeviceIdType implements Serializable {

  private static final long serialVersionUID = 1L;

  @Column(name = "id")
  @GeneratedValue(strategy = GenerationType.AUTO)
  private long id;

"code": "4715",
  "message": "Something went wrong",
  "additionalInfo": "null id generated for:class com.b.DeviceEntity; nested exception is org.hibernate.id.IdentifierGenerationException: null id generated for:class com.b.DeviceEntity"

。 .

错误消息：

@Entity
@Table(name = "device")
public class DeviceEntity implements Serializable {


      private static final long serialVersionUID = 1L;

      @EmbeddedId
      @AttributeOverrides({@AttributeOverride(name = "id" , column= @Column(name = "id",nullable = false))})
      private DeviceIdType deviceIdType;

.

@Embeddable
public class DeviceIdType implements Serializable {

  private static final long serialVersionUID = 1L;

  @Column(name = "id")
  @GeneratedValue(strategy = GenerationType.AUTO)
  private long id;

"code": "4715",
  "message": "Something went wrong",
  "additionalInfo": "null id generated for:class com.b.DeviceEntity; nested exception is org.hibernate.id.IdentifierGenerationException: null id generated for:class com.b.DeviceEntity"

现在，当我使用GenerationType策略时，我得到了这个异常

---

因此，我的问题是：如何在使用@Embedded和@Embedded时设置GenerationType策略？

@Embedded

和

@EmbeddedId

在JPA/Spring数据中大部分时间用于复合主键

---

如果您有一个简单生成的主键，最好将

@Id

注释与

@GenerationType

一起使用，检查这是否有助于->@Id对嵌入对象（值类型）不起作用。它只适用于实体。没错，但在他的例子中，他只嵌入了一个long，可以在主实体类中设置，如果你这样看，那么是的。id可能只是DeviceEntity的一部分，而不是一个可嵌入的对象，但这完全取决于他的设计，也就是说，他是否打算使用其他需要更好OOP方法的字段。