全局ID生成器,一种在分布式系统下用来生成全局唯一ID的工具,一般满足一下要求特性

1.唯一性

2.高性能

3.安全性

4.递增性

5.高可用

@Component
public class RedisIdWorker {/*** 定义一个开始的时间戳(秒级)* @param args*/private static final long BEGIN_TIMESTAMP = 1640995200L;@Autowiredprivate RedisTemplate<String,Object> redisTemplate;public long nextId(String keyPrefix){//1.生成时间戳LocalDateTime now = LocalDateTime.now();long nowSecond = now.toEpochSecond(ZoneOffset.UTC);long timestamp = nowSecond - BEGIN_TIMESTAMP;//2.生成序列号String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));long count = redisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);//这里不会有有空指针//3.拼接并返回return timestamp << 32 | count;}public static void main(String[] args) {//获取从1970年1月1日0时0分0秒开始到2013.3.28日时间的秒数LocalDateTime time = LocalDateTime.of(2013, 3, 28, 0, 0, 0);long second = time.toEpochSecond(ZoneOffset.UTC);System.out.println("second:"+second);}
}

测试

 @Autowiredprivate RedisIdWorker redisIdWorker;private ExecutorService es = Executors.newFixedThreadPool(500);@Testpublic 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 = " + id);}latch.countDown();};long begin = System.currentTimeMillis();for (int i = 0; i < 300; i++) {es.submit(task);}long end = System.currentTimeMillis();System.out.println("time = " + (end - begin));}