java 如何动态初始化Annotation

Question

我有以下结构:

@MappedSuperclass
public class AbstractEntitySequence {

@Id
@GeneratedValue( strategy = GenerationType.SEQUENCE, generator="X?" )
@SequenceGenerator( allocationSize = 1, name = "X?" )
@Column( name = "id", nullable = false, unique = true )
private Long id;

和子实体:

@Entity
@Table( name = "BANK" )
public class Bank extends AbstractEntitySequence implements Serializable {
...
}

和其他实体。

我需要每个实体都有一个序列生成器名称，但我不想将其放置在每个实体中(如 ^C ^V) 是否有可能以某种方式从子类初始化抽象类中的注释(替换 X1)？

Answer 1

您可以定义@SequenceGenerator仅在一个实体类中，它将可用于所有实体，因为根据 JavaDoc:

The scope of the generator name is global to the persistence unit (across all generator types).

因此，您的映射应如下所示:

@Entity
@SequenceGenerator(name="X", allocationSize=1)
public class Bank {

    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="X")
    @Id long id;
}

@Entity
public class InsuranceCompany {

    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="X")
    @Id long id;
}