ZuulFilter 限流

package com.example.apigeteway.filter;

import com.example.apigeteway.exception.RateLimitException;
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;

/**
 * @Title: RateLimitFilter
 * @ProjectName api-geteway
 * @date 2019/12/1712:59
 * @Desc 令牌桶 限流
 */
@Component
public class RateLimitFilter extends ZuulFilter {
    // 每秒放多少个令牌 (100个)
    private static final RateLimiter RATE_LIMITER = RateLimiter.create(100);
    @Override
    public String filterType() {
        return PRE_TYPE;
    }

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

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

    @Override
    public Object run() throws ZuulException {
        if (RATE_LIMITER.tryAcquire()){
            throw new RateLimitException();
        }
        return null;
    }
}