redis实现全局唯一id

package org.utils;

import org.junit.jupiter.api.Test;

import org.springframework.data.redis.core.StringRedisTemplate;

import org.springframework.stereotype.Component;

import javax.annotation.Resource;

import java.time.LocalDateTime;

import java.time.ZoneOffset;

import java.time.format.DateTimeFormatter;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

/**

* @author ClownMing

* Redis实现全局唯一id

*/

@Component

@SuppressWarnings({"all"})

public class RedisIdWorker {

/**

* 开始时间戳

*/

private static final long BEGIN_TIMESTAMP = 1640995200L;

/**

* 序列号的位数

*/

private static final int COUNT_BITS = 32;

private StringRedisTemplate stringRedisTemplate;

public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {

this.stringRedisTemplate = stringRedisTemplate;

}

public long nextId(String keyPrefix){ // 这个key 可以看做是业务key，不同的业务对应不同的key

// 1. 生成时间戳

long timeStamp = LocalDateTime.now().toEpochSecond(ZoneOffset.UTC) - BEGIN_TIMESTAMP;

// 2. 生成序列号

// 2.1 获取当前日期，精确到天

String date = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));

// 2.2 自增长

// 这里即便没有对应的key，redis也会自动帮我们创建

long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date,1);

// 3. 拼接并返回

return timeStamp << COUNT_BITS | 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 = " + second);

}

@Resource

private RedisIdWorker redisIdWorker;

@Test

void testRedisIdWorker() throws InterruptedException {

ExecutorService es = Executors.newFixedThreadPool(10);

CountDownLatch downLatch = new CountDownLatch(200);

Runnable task = () -> {

for (int i = 0; i < 100; i++) {

long id = redisIdWorker.nextId("order");

System.out.println("id = " + id);

}

downLatch.countDown();

};

long begin = System.currentTimeMillis();

for (int i = 0; i < 200; i++) {

es.submit(task);

}

downLatch.await();

long end = System.currentTimeMillis();

System.out.println("总耗时: " + (end - begin));

}

}