SpringCloud Zuul 限流-蒲公英云

SpringCloud Zuul 限流

限流主要是为了防止恶意请求，功能实现放在前置过滤器（Pre）请求被转发之前调用，限流应放在所有的过滤器最前面。

今天介绍的限流方式是令牌桶限流。代码如下

package com.lfv.product.filter;
import org.springframework.stereotype.Component;
import com.google.common.util.concurrent.RateLimiter;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.exception.ZuulException;
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;
/**
 * 限流过滤器
 * @author lf
 *
 */
@Component
public class RateLimterFilter extends ZuulFilter{
    //谷歌令牌桶的实现 100/s 令牌
    private static final RateLimiter RATE_LIMITER = RateLimiter.create(100);
    @Override
    public boolean shouldFilter() {
        return true;
    }
    //没有拿到令牌抛出异常
    @Override
    public Object run() throws ZuulException {
        if(!RATE_LIMITER.tryAcquire()) {
            new RuntimeException();
        }
        return null;
    }
    @Override
    public String filterType() {
        return PRE_TYPE;
    }
    @Override
    public int filterOrder() {
        return SERVLET_DETECTION_FILTER_ORDER - 1;
    }
}