生成订单编号：站点编号前三位 + [5,12]位自增编号

    /**
     * 生成订单编号：站点编号前三位 + [5,12]位自增编号
     * 
     * @param siteCode
     * @return
     * @author jqlin
     */
    private String getOrderNo(String siteCode) {
        String result = siteCode.length() <= 3 ? siteCode : siteCode.substring(0, 3);
        result = result.toUpperCase();
        try {
            String orderNoIncr = "orderNoIncr";
            if(!RedisUtil.exists(orderNoIncr)) {
                RedisUtil.set(orderNoIncr, "0");
            }
            
            //根据redis生成自增ID
            Long seq = RedisUtil.incr(orderNoIncr);
            if(seq == null || seq == 0L) {
                //根据mysql生成自增ID
                seq = (Long)idDao.save(new IdModel());
                result = result + "DB" + Util.getSequence(seq);
            } else {
                result = result + Util.getSequence(seq);
            }
        } catch (Exception e) {
            //根据内存生成自增ID
            result = result + "MM" + String.valueOf(Math.abs(UUID.randomUUID().getMostSignificantBits())).substring(0, 8);
        }
         
        return result;
        
    }

    /**
     * 自增编号范围在[10000,999999999999]，不足补0
     * 
     * @param seq
     * @return
     * @author jqlin
     */
    public static String getSequence(long seq) {
        long defaultLength = 9999L;
        long maxLength = 999999999999L;
        
        if(seq >= maxLength) {
            return String.valueOf(maxLength);
        }
        
        if(seq > defaultLength) {
            return String.valueOf(seq);
        }
          
        int len = 5 - String.valueOf(seq).length();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < len; i++) {
            sb.append('0');
        }
        sb.append(seq);
        return sb.toString();
    }

Spring-boot+分布式下高性能全局对象唯一ID生成器代码+实例演示