Redis生成全局唯一ID的实现方法

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @Author DaBai
 * @Date 2022/3/17 下午 09:25
 * @Version 1.0
 */

@Component
public class RedisIDWorker {
    private static final long BEGIN_TIMESTAMP = 1640995200L;

    /**
     * 序列号位数
     */
    private static final int COUNT_BITS = 32;

    private StringRedisTemplate stringRedisTemplate;

    public RedisIDWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextID(String keyPrefix) {
        //1、生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowScond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowScond – BEGIN_TIMESTAMP;
        //2、生成序列号
        // 2.1 获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern(“yyyy:MM:dd”));
        long count = stringRedisTemplate.opsForValue().increment(“icr” + keyPrefix + “:” + date);

        //3、拼接字符串
        // 时间戳左移32位，然后 或 序列号，有1为1
        long ids = timestamp << COUNT_BITS | count;
        return ids;
    }

    private ExecutorService es = Executors.newFixedThreadPool(500);

    @Test
    public void ShowID() throws InterruptedException {
        CountDownLatch countDownLatch = new CountDownLatch(300);
        Runnable task = () -> {
            for (int i = 0; i < 100; i++) {
                long id = redisIDWorker.nextID(“order”);
                System.out.println(“id = ” + id);
            }
            countDownLatch.countDown();
        };
        long startTime = System.currentTimeMillis();
        for (int i = 0; i < 300; i++) {
            es.submit(task);
        }
        countDownLatch.await();
        long end = System.currentTimeMillis();
        System.out.println(“time = ” + (end – startTime));
    }