java - 实体更新后@Createdby @CreatedDate 为空

Question

我已经在 Spring 应用程序中实现了审计列，当我创建一个新实体时，列被设置，但当我更新实体时，我发现两个 @Createdby 和 @CreatedDate 设置为空，我该如何制作这些创建后列不可更改:

@MappedSuperclass
public abstract class Audit implements Serializable {

    @CreatedBy
    private String createdBy;

    @CreatedDate
    private Date createdDate;

    @LastModifiedBy
    private String lastModifiedBy;

    @LastModifiedDate
    private Date lastModifiedDate;
}

Answer 1

对我来说它有效:

@MappedSuperclass
public class Auditor {

    @Column(name = "created_date", updatable = false)
    @CreatedDate
    private long createdDate;

    @Column(name = "modified_date")
    @LastModifiedDate
    private long modifiedDate;

    @Column(name = "created_by", updatable = false)
    @CreatedBy
    private String createdBy;

    @Column(name = "modified_by")
    @LastModifiedBy
    private String modifiedBy;
}

并扩展类:

@Entity
@EntityListeners(AuditingEntityListener.class)
public class Material extends Auditor {

    @Id
    @SequenceGenerator(name = "seq_material", sequenceName = "seq_material")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seq_material")
    private Long id;

    @Column
    @NotBlank(message = "Nome é um campo obrigatório!.", groups = validacaoProd.class)
    private String nome;

    More...
}

我更新了数据库中的记录:

update material set created_date = 1618418750189, modified_date = 1618418750189