Redis实现全局唯一id的使用示例

@Component
public class RedisIdWorker {
    //开始时间戳
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    public long nextId(String KeyPrefix){
        //生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //生成序列号
        //获取当前格式，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + KeyPrefix + ":" + date);
        //拼接并返回
        //位运算，时间戳向左移动32位，右边空出的0用序列号补充，可以用或运算填充
        return timestamp << 32 | count;
    }
    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println(second);
    }
}

    @Resource
    private RedisIdWorker redisIdWorker;
    private ExecutorService es = Executors.newFixedThreadPool(500);
    @Test
    void testIdWorker() throws InterruptedException {
        CountDownLatch latch = new CountDownLatch(300);
        Runnable task = () ->{
            for(int i = 0; i<100 ;i++){
                long id = redisIdWorker.nextId("order");
                System.out.println(id);
            }
            latch.countDown();
        };
        long begin = System.currentTimeMillis();
        for (int i = 0; i<300 ;i++){
            es.submit(task);
        }
        latch.await();
        long end = System.currentTimeMillis();
        System.out.println(end - begin);
    }