redis实现全局唯一id

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;

@Component
public class RedisIdWorker {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    private static final long BEGIN_TIMESTAMP = 1672531200L;
    private static final int COUNT_BITS = 32;

    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
        //获取当前日期,精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //拼接并返回
        return timestamp << COUNT_BITS | count;
    }
}

测试

package com.hmdp;

import com.hmdp.service.impl.ShopServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.annotation.Primary;

import javax.annotation.Resource;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

@SpringBootTest
class ApplicationTests {
    @Autowired
    private RedisIdWorker redisIdWorker;
    //线程池500个
    private ExecutorService es = Executors.newFixedThreadPool(500);

    @Test
    void testIdWorker() throws InterruptedException {
        //开启一个倒计时的插销
        CountDownLatch countDownLatch = new CountDownLatch(300);
        //开启线程
        Runnable task = () -> {
            for (int i = 0; i < 100; i++) {
                long order = redisIdWorker.nextId("order");
                System.out.println(order);
            }
            //倒计时-
            countDownLatch.countDown();
        };
        long begin = System.currentTimeMillis();
        for (int i = 0; i < 300; i++) {
            es.submit(task);
        }
        //当倒计时为0立马停止等待
        countDownLatch.await();
        long end = System.currentTimeMillis();
        System.out.println(end - begin);
    }


}