@Component
public class MybatisAuditHandler implements MetaObjectHandler {
 @Override
 public void insertFill(MetaObject metaObject) {
  // 声明自动填充字段的逻辑。
  String userId = AuthHolder.getCurrentUserId();
  this.strictInsertFill(metaObject,"creator",String.class, userId);
  this.strictInsertFill(metaObject,"createTime", LocalDateTime.class,LocalDateTime.now());
 }

 @Override
 public void updateFill(MetaObject metaObject) {
  // 声明自动填充字段的逻辑。
  String userId = AuthHolder.getCurrentUserId();
  this.strictUpdateFill(metaObject,"updater",String.class,userId);
  this.strictUpdateFill(metaObject,"updateTime", LocalDateTime.class,LocalDateTime.now());
 }
}

public abstract class BaseEntity<T extends Model<? extends Model<T> {

 @TableField(fill = FieldFill.INSERT)
 private String creator;
 @TableField(fill = FieldFill.INSERT)
 private LocalDateTime addTime;
 @TableField(fill = FieldFill.UPDATE)
 private String updater;
 @TableField(fill = FieldFill.UPDATE)
 private LocalDateTime updateTime;
}

@Data
@EqualsAndHashCode(callSuper = false)
public class UserInfo extends BaseEntity<UserInfo> {
 @TableId(value = "user_id", type = IdType.ASSIGN_ID)
 private String userId;
 private String username;

 @Override
 protected Serializable pkVal() {
  return this.userId;
 }
}