redis限流java写法

Redis限流可以使用令牌桶算法实现，Java代码如下：

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

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

    public boolean acquire() {
        long now = System.currentTimeMillis();
        Pipeline pipeline = jedis.pipelined();
        pipeline.multi();
        pipeline.zremrangeByScore(key, 0, now - interval);
        pipeline.zcard(key);
        Response<Long> countResponse = pipeline.zadd(key, now, String.valueOf(now));
        pipeline.expire(key, interval / 1000);
        pipeline.exec();
        pipeline.sync();
        long count = countResponse.get();
        return count <= capacity && count > rate;
    }
}

其中，jedis是Redis客户端，key是限流的键名，capacity是桶的容量，rate是每秒放入桶中的令牌数，interval是桶的时间间隔。acquire方法用于尝试获取令牌，如果获取成功返回true，否则返回false。