SpringCloud Zuul过滤器和谷歌Gauva实现限流

前提：

已经配置Zuul网关

参考：

https://www.jb51.net/article/182894.htm

限流方式：

1）nginx层限流

2）网关层限流

1.添加限流过滤器

import com.alibaba.fastjson.JSON;
import com.google.common.util.concurrent.RateLimiter;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.apache.commons.lang.StringUtils;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;

import javax.servlet.http.HttpServletRequest;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

/**
* 订单限流接口
*/
@Component
public class OrderRateLimiterFilter extends ZuulFilter {

//每秒产生1000个令牌
 private static final RateLimiter RATE_LIMITER = RateLimiter.create(1000);

@Override
 public String filterType() {
   return PRE_TYPE;
 }

@Override
 public int filterOrder() {
   return -4;
 }

@Override
 public boolean shouldFilter() {

RequestContext context = RequestContext.getCurrentContext();
   HttpServletRequest request = context.getRequest();

///apigateway/order/api/v1/order/test
   System.out.println(request.getRequestURI());
   //http://127.0.0.1:9000/apigateway/order/api/v1/order/test
   System.out.println(request.getRequestURL());

//限流的接口
   List<String> noFIlter = new ArrayList<>();
   noFIlter.add("/apigateway/order/**");

AntPathMatcher matcher = new AntPathMatcher();
   for (String pattern : noFIlter) {//pattern--/user/**
     if (StringUtils.isNotEmpty(pattern)
         && matcher.match(pattern, request.getRequestURI())) {
       return true;
     }
   }

return false;
 }

@Override
 public Object run() throws ZuulException {

//可以用JMeter来进行测试
   RequestContext context = RequestContext.getCurrentContext();
   //tryAcquire达到最大流量时,立刻限流,也可以配置参数
   if (!RATE_LIMITER.tryAcquire()) {
     Map<String, Object> result = new HashMap<>();
     result.put("code", 429);
     result.put("msg", "目前访问量过大,限流了...");

context.setSendZuulResponse(false);
     context.setResponseStatusCode(HttpStatus.TOO_MANY_REQUESTS.value());
     context.setResponseBody(JSON.toJSONString(result));
     //解决中文乱码
     context.getResponse().setCharacterEncoding("UTF-8");
     context.getResponse().setContentType("text/html;charset=UTF-8");
   }

return null;
 }
}

令牌桶限流图解

来源：https://www.cnblogs.com/tianhengblogs/p/12501235.html