spring boot 中使用MybatisPlus的自动填充createTime和updateTime

首先需要在实体类的字段上加上注解，并且将类型更改为LocalDateTime

    @TableField(fill = FieldFill.INSERT)
    @JsonInclude(value = JsonInclude.Include.NON_NULL)
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime createTime;

    @TableField(fill = FieldFill.INSERT_UPDATE)
    @JsonInclude(value = JsonInclude.Include.NON_NULL)
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime updateTime;

配置MybatisPlus相关的Handler

@Component
public class MyMetaObjectHandler implements MetaObjectHandler {

    /**
     * 新增填充创建时间
     *
     * @param metaObject
     */
    @Override
    public void insertFill(MetaObject metaObject) {
        this.strictInsertFill(metaObject, "createTime", () -> LocalDateTime.now(), LocalDateTime.class);
        this.strictUpdateFill(metaObject, "updateTime", () -> LocalDateTime.now(), LocalDateTime.class);
    }

    /**
     * 更新填充更新时间
     *
     * @param metaObject
     */
    @Override
    public void updateFill(MetaObject metaObject) {
        this.strictUpdateFill(metaObject, "updateTime", () -> LocalDateTime.now(), LocalDateTime.class);
    }

}

修改Jackson的自定义序列化器，增加处理LocalDateTime的方法

ObjectMapper customObjectMapper = new ObjectMapper();

        /**
         * 处理LocalDateTime序列化
         * 在使用MybatisPlus的自动填充功能时，需要指定字段类型为LocalDateTime
         * 但是Jackson在默认状况下序列化LocalDateTime会报错
         * 需要自定义序列化器，将LocalDateTime序列化为字符串
         */

        JavaTimeModule javaTimeModule = new JavaTimeModule();

        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

        customObjectMapper.registerModule(javaTimeModule);

        customObjectMapper.activateDefaultTyping(
                LaissezFaireSubTypeValidator.instance,
                ObjectMapper.DefaultTyping.NON_FINAL,
                JsonTypeInfo.As.WRAPPER_ARRAY);

        customObjectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

        this.objectMapper = customObjectMapper;