Mybatis自动填充创建时间和更新时间

通过实现MetaObjectHandler，重写insertFill、updateFill方法来设置创建时间和更新时间

import com.aigostar.cloud.common.utility.UtcDateTime;
import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;

@Component
@Slf4j
public class MysqlMetaObjectHandler implements MetaObjectHandler {

    @Override
    public void insertFill(MetaObject metaObject) {
        Object createDatetime = this.getFieldValByName("createTime", metaObject);
        if (createDatetime == null) {
            this.strictInsertFill(metaObject, "createTime", LocalDateTime.class, UtcDateTime.now());
        }
        Object syStamp = this.getFieldValByName("syStamp", metaObject);
        if (syStamp == null) {
            this.strictInsertFill(metaObject, "syStamp", LocalDateTime.class, UtcDateTime.now());
        }
        this.strictUpdateFill(metaObject, "updateTime", LocalDateTime.class, UtcDateTime.now());
    }

    @Override
    public void updateFill(MetaObject metaObject) {
    	// updateTime 不用判空 直接设置更新时间
        this.setFieldValByName("updateTime", UtcDateTime.now(), metaObject);
        Object syStamp = this.getFieldValByName("syStamp", metaObject);
        if (syStamp == null) {
            this.strictInsertFill(metaObject, "syStamp", LocalDateTime.class, UtcDateTime.now());
        }
    }
}