使用 guava 实现网站某个URL限流功能

1.限流类
package com.leimingtech.admin.utils;

import com.google.common.util.concurrent.RateLimiter;
import com.leimingtech.core.cache.jedis.JedisUtils;
import com.leimingtech.extend.module.payment.wechat.mobile.util.MD5Util;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.http.HttpServletRequest;
import java.util.Enumeration;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;

/**
* Author by gjp, Date on 2019/9/23.
* 页面访问频率限制
*/
@Slf4j
public class PageRate {


    public static final PageRate pageRate = new PageRate();
    ConcurrentHashMap<String, RateLimiter> rateLimiterPool = new ConcurrentHashMap<String, RateLimiter>();
    //每秒钟访问次数
    private int RATE_NUM = 2;
    private int LIMIT_DATE=1000 * 60 * 60;


    public static PageRate getInstance(){
        return pageRate;
    }
    /**
     * 访问频率限制
     * @param request
     * @return
     */
    public  boolean limitReqRate(HttpServletRequest request){
        boolean flag = true;
        String url = request.getRequestURI();
        String ip = getIpAddress(request);

        StringBuffer stringBuffer =  new StringBuffer(60);
        stringBuffer.append(url).append("-").append(ip);

        String key = "LYPT:RATE:"+MD5Util.MD5Encode(stringBuffer.toString(),"UTF-8");

        //检查key值是否存在
        if(JedisUtils.exists(key)){
            log.info("该用户的ip地址已经被禁止访问，key={}",key);
            flag = false;
        }

        if (rateLimiterPool.containsKey(key)) {//已经加入计数器
            if (rateLimiterPool.get(key).tryAcquire(1, TimeUnit.SECONDS)) {
                log.info("获取的访问权限",key);
            }else {
                System.out.println("超出最大访问限制 "+key);
                JedisUtils.set(key,stringBuffer.toString(),LIMIT_DATE);
            }
        }else {
            //没有加入计数器
            log.info("加入访问权限列表",key);
            RateLimiter rateLimiter = RateLimiter.create(RATE_NUM);
            rateLimiterPool.put(key, rateLimiter);

        }

        return flag;
    }


    /**
     * 获取ip地址
     * @param request
     * @return
     */
    public String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }


    /**
     * 遍历限速池
     * @return
     */
    public String listKey(){
        StringBuffer sb =new StringBuffer(100);
        Enumeration<String> enu = rateLimiterPool.keys();
        while (enu.hasMoreElements()){
            sb.append(enu.nextElement()).append("-");
        }
        return sb.toString();
    }

    /**
     * 删除 key
     * @param key
     * @return
     */
    public boolean delByKey(final String key){
        RateLimiter limiter = rateLimiterPool.remove(key);
        boolean flag =false;
        if(null !=limiter){
            flag = true;
        }
        return flag;
    }


    /**
     *
     * @param key
     * @param num
     * @return
     */
    public RateLimiter put(String key,String num){
        RateLimiter rateLimiter = RateLimiter.create(Double.parseDouble(num));
        return  rateLimiterPool.put(key,rateLimiter);
    }

    /**
     *
     * @param key
     * @param rateLimiter
     * @return
     */
    public RateLimiter put(String key,RateLimiter rateLimiter){
        return  rateLimiterPool.put(key,rateLimiter);
    }




}




2.使用限流方法

@RequestMapping(value = "/login")
    public String login(Model model,HttpServletRequest httpServletRequest) {
        //开启限流功能
        boolean rateFlag = PageRate.getInstance().limitReqRate(httpServletRequest);
        if(!rateFlag){
            return "/index/rate";
        }

        try {
            Subject subject = SecurityUtils.getSubject();
            if (subject.isAuthenticated()) {
                return "redirect:/";
            }
            return "/index/login";
        } catch (Exception e) {
            log.error("跳转登录页面异常：", e);
        }
        return null;
    }