Java Redis实现分布式锁

相关解决方案

代码实现

tryLock 方法

public String tryLock(String name, int expire) {
    name = name + "_lock";
    String token = UUID.randomUUID().toString();
    RedisConnectionFactory factory = stringRedisTemplate.getConnectionFactory();
    RedisConnection conn = factory.getConnection();
    try {

        //参考redis命令：
        //set key value [EX seconds] [PX milliseconds] [NX|XX]
        Boolean result = conn.set(
                name.getBytes(),
                token.getBytes(),
                Expiration.from(expire, TimeUnit.MILLISECONDS),
                RedisStringCommands.SetOption.SET_IF_ABSENT //NX
        );
        if (result != null && result)
            return token;
    } finally {
        RedisConnectionUtils.releaseConnection(conn, factory,false);
    }
    return null;
}

方法加锁（主要看token这个参数）

/**
 * 未来数据定时刷新
 */
@Scheduled(cron = "0 */1 * * * ?")
public void refresh() {

    String token = cacheService.tryLock("FUTRUE_TASK_SYNC", 1000 * 30);

    if(StringUtils.isNotBlank(token)){
        log.info("未来数据定时刷新---定时任务");

        //获取所有未来数据的集合key
        Set futureKeys = cacheService.scan(ScheduleConstants.FUTURE + "*");
        for (String futureKey : futureKeys) {
            //future_100_50

            //获取当前数据的key  topic
            String topicKey = ScheduleConstants.TOPIC + futureKey.split(ScheduleConstants.FUTURE)[1];

            //按照key和分值查询符合条件的数据
            Set tasks = cacheService.zRangeByScore(futureKey, 0, System.currentTimeMillis());

            //同步数据
            if (!tasks.isEmpty()) {
                cacheService.refreshWithPipeline(futureKey, topicKey, tasks);
                log.info("成功的将" + futureKey + "刷新到了" + topicKey);
            }
        }
    }
}

相关链接：

Springboot集成Redis - 掘金 (juejin.cn)

利用redis解决缓存击穿问题 - 掘金 (juejin.cn)