Zuul的限流操作

算法：令牌桶

Guava已经实现了这个算法：RateLimiter

放上代码：

package van.gateway.filter;

import com.google.common.util.concurrent.RateLimiter;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;

import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SERVLET_DETECTION_FILTER_ORDER;

/**
 * @author Van
 * @date 2020/4/18 - 10:29
 */
@Component
public class RateLimitFilter extends ZuulFilter {
    private static final RateLimiter RATE_LIMITER=RateLimiter.create(100);//每秒放100个令牌
    @Override
    public String filterType() {
        return PRE_TYPE;
    }

    @Override
    public int filterOrder() {
        return SERVLET_DETECTION_FILTER_ORDER-1;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() throws ZuulException {
        //如果没有取到令牌
        if (!RATE_LIMITER.tryAcquire()){
            //可以抛错误，或者其他什么的。
        }
        return null;
    }
}