public static Date parseDate(String dateString, String dateFormat) throws ParseException {
        if (StringUtils.isEmpty(dateFormat)) {
            dateFormat = switchDateFormat(dateString);
        }
        return getCacheDateFormat(dateFormat).parse(dateString);
    }
convert string to date

@param dateString
@param dateFormat
@return
@throws ParseException
fastexcel-core/src/main/java/cn/idev/excel/util/DateUtils.java