java如何根据日期生成单号

 select a.* from t_solid_waste_production a
 WHERE deleted = 0 and TO_DAYS(create_time) = TO_DAYS(NOW())
order by create_time desc limit 1

SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");
String date = df.format(new Date());
String recordNumber = "CF" + date + "001";

if (lastData != null){
   Format f1=new DecimalFormat("000");
   recordNumber = "CF" + date + f1.format((Integer.parseInt(lastData.getRecordNumber().substring(lastData.getRecordNumber().length() - 3)) + 1));
   }

@ApiOperation("异常单号生成")
    @GetMapping("getCode")
    public Response<Object> getCode(){
        return new Response<>().success().data(exceptionItemService.getCode());
    }

@Override
    public String getCode() {
        //前缀
        String prefix = "YC-";
        //后缀
        String lastIndex;
        //获取最大三位数
        Integer maxCode = exceptionItemMapper.selectMaxCode(prefix);
        //查询出数据库中当前最大的单号，如果没有则说明今天还未添加一条数据，有的话则将最大的查出来 +1
        if (maxCode != null && maxCode <= 8) {
            maxCode += 1;
            //Integer转换为字符串
            String i = String.valueOf(maxCode);
            lastIndex = "00" + i;
        } else if (maxCode != null && maxCode <= 98) {
            maxCode += 1;
            String i = String.valueOf(maxCode);
            lastIndex = "0" + i;
        } else if (maxCode != null) {
            maxCode += 1;
            lastIndex = String.valueOf(maxCode);
        } else {
            lastIndex = "001";
        }
        // 中间部分 “20231211”
        String middle = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        //设置新的异常单号 YC-20231203-001
        return prefix + middle + "-" + lastIndex;
    }

Integer maxCode = exceptionItemMapper.selectMaxCode(prefix) 

<select id="selectMaxCode" resultType="java.lang.Integer">
        SELECT MAX(CAST(SUBSTRING(exception_code, LENGTH(exception_code) - 2) AS INTEGER))
        FROM qc_exception_item
        WHERE exception_code LIKE CONCAT(#{prefix}, TO_CHAR(NOW(), 'YYYYMMDD'),'-%','%');
</select>

WHERE exception_code LIKE CONCAT(#{prefix}, TO_CHAR(NOW(), 'YYYYMMDD'),'-%','%')  

TO_CHAR(NOW(), 'YYYYMMDD') 

DATE_FORMAT(NOW(), '%Y%m%d')