MybatisPlus自动填充-MetaObjectHandler接口

一、介绍

MetaObjectHandler是MybatisPlus提供的一个扩展接口，使用这个接口可以在插入和更新时为一些自段设置默认值（类似自动填充策略）。

二、应用

@Slf4j
public class CreateAndUpdateMetaObjectHandler implements MetaObjectHandler {

    @Override
    public void insertFill(MetaObject metaObject) {
        try {
            if (ObjectUtil.isNotNull(metaObject) && metaObject.getOriginalObject() instanceof BaseEntity) {
                this.strictInsertFill(metaObject, "status", Integer.class, 0);

                BaseEntity baseEntity = (BaseEntity) metaObject.getOriginalObject();
                LocalDateTime current = ObjectUtil.isNotNull(baseEntity.getCreateTime())
                    ? baseEntity.getCreateTime() : LocalDateTime.now();
                baseEntity.setCreateTime(current);
                baseEntity.setUpdateTime(current);
                String username = StringUtils.isNotBlank(baseEntity.getCreateBy())
                    ? baseEntity.getCreateBy() : getLoginUsername();
                String nickname = StringUtils.isNotBlank(baseEntity.getCreateName())
                        ? baseEntity.getCreateName() : getLoginNickName();

                // 当前已登录 且 创建人为空 则填充
                baseEntity.setCreateBy(username);
                baseEntity.setCreateName(nickname);
                // 当前已登录 且 更新人为空 则填充
                baseEntity.setUpdateBy(username);
                baseEntity.setUpdateName(nickname);
            }
        } catch (Exception e) {
            throw new ServiceException("自动注入异常 => " + e.getMessage(), HttpStatus.HTTP_UNAUTHORIZED);
        }
    }

    @Override
    public void updateFill(MetaObject metaObject) {
        try {
            if (ObjectUtil.isNotNull(metaObject) && metaObject.getOriginalObject() instanceof BaseEntity) {
                BaseEntity baseEntity = (BaseEntity) metaObject.getOriginalObject();
                LocalDateTime current = LocalDateTime.now();
                // 更新时间填充(不管为不为空)
                baseEntity.setUpdateTime(current);
                String username = getLoginUsername();
                String nickname = getLoginNickName();

                // 当前已登录 更新人填充(不管为不为空)
                if (StringUtils.isNotBlank(username)) {
                    baseEntity.setUpdateBy(username);
                }
                if(StringUtils.isNotEmpty(nickname)) {
                    baseEntity.setUpdateName(nickname);
                }
            }
        } catch (Exception e) {
            throw new ServiceException("自动注入异常 => " + e.getMessage(), HttpStatus.HTTP_UNAUTHORIZED);
        }
    }

三、实体类加@TableField(fill = FieldFill.INSERT_UPDATE)

@Data
public class BaseEntity implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * 搜索值
     */
    @JsonIgnore
    @TableField(exist = false)
    private String searchValue;

    /**
     * 创建者
     */
    @TableField(fill = FieldFill.INSERT)
    private String createBy;

    /**
     * 创建昵称
     */
    @TableField(fill = FieldFill.INSERT)
    private String createName;

    /**
     * 创建时间
     */
    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;

    /**
     * 更新者
     */
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private String updateBy;

    /**
     * 更新者昵称
     */
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private String updateName;

    /**
     * 更新时间
     */
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;

    /**
     * 请求参数
     */
    @JsonInclude(JsonInclude.Include.NON_EMPTY)
    @TableField(exist = false)
    private Map params = new HashMap<>();

}

四、config配置

    @Bean
    public MetaObjectHandler metaObjectHandler() {
        return new CreateAndUpdateMetaObjectHandler();
    }