使用redis实现自增序列

来源：

https://www.cnblogs.com/shigj/p/11215262.html

public class TestService {
 
	@Resource
	RedisTemplate<String, Object> redisTemplate;
	
	public String getId() {
	    SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");
	    Date date=new Date();
	    String formatDate=sdf.format(date);
	    String key="key"+formatDate;
	    Long incr = getIncr(key, getCurrent2TodayEndMillisTime());
	    if(incr==0) {
	    	incr = getIncr(key, getCurrent2TodayEndMillisTime());//从001开始
	    }
	    DecimalFormat df=new DecimalFormat("000");//三位序列号
	    return formatDate+df.format(incr);
	}
	
	public Long getIncr(String key, long liveTime) {
            RedisAtomicLong entityIdCounter = new RedisAtomicLong(key, redisTemplate.getConnectionFactory());
            Long increment = entityIdCounter.getAndIncrement();
 
            if ((null == increment || increment.longValue() == 0) && liveTime > 0) {//初始设置过期时间
                entityIdCounter.expire(liveTime, TimeUnit.MILLISECONDS);//单位毫秒
            }
            return increment;
        }
 
	//现在到今天结束的毫秒数
	public Long getCurrent2TodayEndMillisTime() {
	    Calendar todayEnd = Calendar.getInstance();
	    // Calendar.HOUR 12小时制
	    // HOUR_OF_DAY 24小时制
	    todayEnd.set(Calendar.HOUR_OF_DAY, 23); 
	    todayEnd.set(Calendar.MINUTE, 59);
	    todayEnd.set(Calendar.SECOND, 59);
	    todayEnd.set(Calendar.MILLISECOND, 999);
	    return todayEnd.getTimeInMillis()-new Date().getTime();
	}
	
}