使用redis存储流水号，代码如下：

import cn.hutool.core.date.DateUtil;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;@Component
public class RedisSerialUtil {private RedisTemplate<String, Object> redisTemplate;public RedisSerialUtil(RedisTemplate<String, Object> redisTemplate) {this.redisTemplate = redisTemplate;}/*** @param dateFormat: 日期格式 yyyyMMdd* @param redisKeyPrefix: redis的key 自定义* @param initialValue: 初始序列号* @param delta: 自增步长* @param formatSpecifier: 补全位数 %03d* return String* {@link String}* @author Miki* @date 2023-10-10* @description 默认当天的流水*/public String generateCode(String dateFormat, String redisKeyPrefix, String initialValue, long delta, String formatSpecifier) {String serialCode = "";String today = DateUtil.today();String formatDate = DateUtil.format(DateUtil.parse(today), dateFormat);String redisKey = redisKeyPrefix.concat(formatDate);// 获取缓存数据Long redisValue = redisTemplate.opsForValue().increment(redisKey, delta);if (redisValue == null || redisValue.equals(delta)) {redisTemplate.opsForValue().set(redisKey, initialValue);serialCode = String.format(formatSpecifier, Integer.parseInt(initialValue));} else {serialCode = String.format(formatSpecifier, redisValue);}return serialCode;}
}

调用代码如下：

public class TestSerial{@Autowiredprivate RedisTemplate<String, Object> redisTemplate;RedisSerialUtil redisSerialUtil = new RedisSerialUtil(redisTemplate);String dateFormat = "yyyyMMdd";String redisKeyPrefix = "redisKeyPrefix:";String formatSpecifier = "%03d";// 生成流水号String serialCode = redisSerialUtil.generateCode(dateFormat, redisKeyPrefix, "1", 1, formatSpecifier);// 返回的serialCode 为001，002，只有流水号// redis中的key = redisKeyPrefix + dateFormat ;value为流水号}