public boolean allowRequest(String requestKey) {
        // 定義一個(gè)時(shí)間窗口為1分鐘
        long windowSize = Duration.ofMinutes(1).toSeconds();

        // 定義時(shí)間窗口內(nèi)請(qǐng)求閾值為100
        long limit = 100;

        // 當(dāng)前時(shí)間戳
        long currentTime = System.currentTimeMillis();

        // 窗口開始時(shí)間為當(dāng)前時(shí)間戳 - 窗口大小
        long windowStart = currentTime - windowSize * 1000;

        // 刪除當(dāng)前窗口開始之前的所有數(shù)據(jù)
        Jedis.zremrangeByScore(requestKey, "0", String.valueOf(windowStart));

        // 計(jì)算當(dāng)前窗口內(nèi)的請(qǐng)求總數(shù)
        long count = Jedis.zcard(requestKey);

        if (count < limit) {
            // 如果允許訪問，則將當(dāng)前請(qǐng)求加到窗口內(nèi)
            Jedis.zadd(requestKey, currentTime, String.valueOf(currentTime));
            return true;
        }
        return false;
    }
}

import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
import org.redisson.api.RRateLimiter;
import org.redisson.api.RateIntervalUnit;
import org.redisson.api.RateType;
import org.redisson.api.RedissonClient;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.web.filter.OncePerRequestFilter;

public class RateLimiterFilter extends OncePerRequestFilter {

    private final Logger log = LoggerFactory.getLogger(RateLimiterFilter.class);

    private static final String RATE_LIMIT_KEY = "rateLimit:yourApiKey";
    private static final int MAX_REQUESTS_PER_MINUTE = 10;

    private final RedissonClient redissonClient;

    public RateLimiterFilter(RedissonClient redissonClient) {
        this.redissonClient = redissonClient;
    }
    
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
        throws ServletException, IOException {
        RRateLimiter rateLimiter = redissonClient.getRateLimiter(RATE_LIMIT_KEY);
        // rateLimiter.trySetRate就是設(shè)置限流參數(shù)，RateType有兩種，OVERALL是全局限流 ，PER_CLIENT是單Client限流（可以認(rèn)為就是單機(jī)限流），這里我們只討論全局模式。
        // 而后面三個(gè)參數(shù)的作用就是設(shè)置在多長(zhǎng)時(shí)間窗口內(nèi)（rateInterval+IntervalUnit），許可總量不超過多少（rate）
        // 上面代碼中我設(shè)置的值就是1分鐘內(nèi)總許可數(shù)不超過10個(gè)
        rateLimiter.trySetRate(RateType.OVERALL, MAX_REQUESTS_PER_MINUTE, 1, RateIntervalUnit.MINUTES);
        // 調(diào)用rateLimiter的tryAcquire()或者acquire()方法即可獲取許可
        if (!rateLimiter.tryAcquire()) {
            
            String path = request.getRequestURI().substring(request.getContextPath().length());
            log.error("當(dāng)前請(qǐng)求觸發(fā)限流策略，請(qǐng)求: {} 已經(jīng)被限流.", path);

            response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
            response.getWriter().write("Too many requests!");
            return;
        }
        filterChain.doFilter(request, response);
    }
}