redis限流java写法

可以使用 Redis 的令牌桶算法来实现限流，具体的 Java 代码实现可以参考以下示例：

public class RedisRateLimiter {
    private final Jedis jedis;
    private final String key;
    private final int limit;
    private final long interval;

    public RedisRateLimiter(Jedis jedis, String key, int limit, long interval) {
        this.jedis = jedis;
        this.key = key;
        this.limit = limit;
        this.interval = interval;
    }

    public boolean acquire() {
        long now = System.currentTimeMillis();
        Pipeline pipeline = jedis.pipelined();
        pipeline.multi();
        pipeline.zadd(key, now, String.valueOf(now));
        pipeline.zremrangeByScore(key, 0, now - interval);
        pipeline.zcard(key);
        pipeline.expire(key, (int) (interval / 1000));
        List<Object> results = pipeline.exec();
        long count = (Long) results.get(results.size() - 2);
        return count <= limit;
    }
}

使用时，可以先创建一个 RedisRateLimiter 对象，然后在需要进行限流的地方调用 acquire() 方法，如果返回 true，表示可以继续执行业务逻辑，否则需要等待一段时间后再尝试。例如：

Jedis jedis = new Jedis("localhost");
RedisRateLimiter limiter = new RedisRateLimiter(jedis, "my-limiter", 10, 1000);
while (true) {
    if (limiter.acquire()) {
        // 执行业务逻辑
    } else {
        Thread.sleep(100);
    }
}