springboot 拦截高频率访问

写了一个小站点，帮助我们学校的同学应付考试。当然也赚了一点钱…但就是有一些调皮的同学过来攻击我。无脑扫描我的web接口，之前用的别人的内网穿透的工具，因为本身价格不是很高，所以他对 TCP连接数有分钟限制，导致了我的站点无法被正常访问。但是我拦截了高频率访问，只是限制了他爬取我的web资源，并不能根本解决TCP连接限制这个问题，后来，我买了阿里云，自己搭建内网穿透。问题解决。

好了废话不多说，直接进入主题。
开启拦截的整个过程：
访问 站点—记录ip—若存在则，计算访问速度是否达到阈值，达到则拉黑名单，直接返回JSON字符串。若不存在，加入该ip。
接下来直接贴代码：

1.配置过滤器

/**
 * @Auther: raven
 * @Date: 2019/12/9 14:04
 * @Description:
 */


import util.IpUtils;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 自定义过滤器，用来判断IP访问次数是否超限
 * 如果前台用户访问网站的频率过快（达到超过50次/秒），则判定该ip恶意刷新操作，
 * 限制该IP的访问，1小时后自己解除限制
 *
 * @author wukaikai
 *
 */
@WebFilter(urlPatterns="/*")
public class IpFilter implements Filter{

    /**
     * 默认限制时间（单位：ms）
     */
    private static final long LIMITED_TIME_MILLIS = 60 * 60 * 1000;

    /**
     * 用户连续访问最高阀值，超过该值则认定为恶意操作的IP，进行限制
     */
    private static final int LIMIT_NUMBER = 100;

    /**
     * 用户访问最小安全时间，在该时间内如果访问次数大于阀值，则记录为恶意IP，否则视为正常访问
     */
    private static final int MIN_SAFE_TIME = 5000;
    private FilterConfig config;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        this.config = filterConfig;    //设置属性filterConfig
    }

    /* (non-Javadoc)
     * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
     */
    @SuppressWarnings("unchecked")
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
        throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        ServletContext context = config.getServletContext();
        // 获取限制IP存储器：存储被限制的IP信息
        Map<String, Long> limitedIpMap = (Map<String, Long>) context.getAttribute("limitedIpMap");
        // 过滤受限的IP
        filterLimitedIpMap(limitedIpMap);
        // 获取用户IP
        String ip = IpUtils.getIpAddr(request);
       // System.err.println("ip:"+ip);
        // 判断是否是被限制的IP，如果是则跳到异常页面
        if (isLimitedIP(limitedIpMap, ip)) {
            long limitedTime = limitedIpMap.get(ip) - System.currentTimeMillis();
            // 剩余限制时间(用为从毫秒到秒转化的一定会存在些许误差，但基本可以忽略不计)
            request.setAttribute("remainingTime", ((limitedTime / 1000) + (limitedTime % 1000 > 0 ? 1 : 0)));
           
            System.err.println("ip访问过于频繁："+ip);
            response.setStatus(403);
            response.setCharacterEncoding("utf-8");    //设置输出内容编码格式
            response.setContentType("text/html;charset=utf-8");
            PrintWriter out = response.getWriter();
            out.println("由于您访问过于频繁，被系统自动认定为机器人。1个小时自动解除");
            return;
        }
        // 获取IP存储器
        Map<String, Long[]> ipMap = (Map<String, Long[]>) context.getAttribute("ipMap");
        // 判断存储器中是否存在当前IP，如果没有则为初次访问，初始化该ip
        // 如果存在当前ip，则验证当前ip的访问次数
        // 如果大于限制阀值，判断达到阀值的时间，如果不大于[用户访问最小安全时间]则视为恶意访问，跳转到异常页面
        if (ipMap.containsKey(ip)) {
            Long[] ipInfo = ipMap.get(ip);
            ipInfo[0] = ipInfo[0] + 1;
          //  System.out.println("当前第[" + (ipInfo[0]) + "]次访问");
            if (ipInfo[0] > LIMIT_NUMBER) {
                Long ipAccessTime = ipInfo[1];
                Long currentTimeMillis = System.currentTimeMillis();
                if (currentTimeMillis - ipAccessTime <= MIN_SAFE_TIME) {
                    limitedIpMap.put(ip, currentTimeMillis + LIMITED_TIME_MILLIS);
                    request.setAttribute("remainingTime", LIMITED_TIME_MILLIS);
                    System.err.println("ip访问过于频繁："+ip);
                    request.getRequestDispatcher("/error/overLimitIP").forward(request, response);
                    return;
                } else {
                    initIpVisitsNumber(ipMap, ip);
                }
            }
        } else {
            initIpVisitsNumber(ipMap, ip);
            //System.out.println("您首次访问该网站");
        }
        context.setAttribute("ipMap", ipMap);
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {
        // TODO Auto-generated method stub
    }

    /**
     * @Description 过滤受限的IP，剔除已经到期的限制IP
     * @param limitedIpMap
     */
    private void filterLimitedIpMap(Map<String, Long> limitedIpMap) {
        if (limitedIpMap == null) {
            return;
        }
        Set<String> keys = limitedIpMap.keySet();
        Iterator<String> keyIt = keys.iterator();
        long currentTimeMillis = System.currentTimeMillis();
        while (keyIt.hasNext()) {
            long expireTimeMillis = limitedIpMap.get(keyIt.next());
            if (expireTimeMillis <= currentTimeMillis) {
                keyIt.remove();
            }
        }
    }

    /**
     * @Description 是否是被限制的IP
     * @param limitedIpMap
     * @param ip
     * @return true : 被限制 | false : 正常
     */
    private boolean isLimitedIP(Map<String, Long> limitedIpMap, String ip) {
        if (limitedIpMap == null || ip == null) {
            // 没有被限制
            return false;
        }
        Set<String> keys = limitedIpMap.keySet();
        Iterator<String> keyIt = keys.iterator();
        while (keyIt.hasNext()) {
            String key = keyIt.next();
            if (key.equals(ip)) {
                // 被限制的IP
                return true;
            }
        }
        return false;
    }

    /**
     * 初始化用户访问次数和访问时间
     *
     * @param ipMap
     * @param ip
     */
    private void initIpVisitsNumber(Map<String, Long[]> ipMap, String ip) {
        Long[] ipInfo = new Long[2];
        ipInfo[0] = 0L;// 访问次数
        ipInfo[1] = System.currentTimeMillis();// 初次访问时间
        ipMap.put(ip, ipInfo);
    }

}

配置监听器初始化一些参数

package config;

/**
 * @Auther: raven
 * @Date: 2019/12/9 14:04
 * @Description:
 */


import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@WebListener
public class MyApplicationListener implements ServletContextListener {
    private Logger logger =  LoggerFactory.getLogger(MyApplicationListener.class);
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        logger.info("liting: contextInitialized");
        System.err.println("MyApplicationListener初始化成功");
        ServletContext context = sce.getServletContext();
        // IP存储器
        Map<String, Long[]> ipMap = new HashMap<String, Long[]>();
        context.setAttribute("ipMap", ipMap);
        // 限制IP存储器：存储被限制的IP信息
        Map<String, Long> limitedIpMap = new HashMap<String, Long>();
        context.setAttribute("limitedIpMap", limitedIpMap);
        logger.info("ipmap："+ipMap.toString()+";limitedIpMap:"+limitedIpMap.toString()+"初始化成功。。。。。");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        // TODO Auto-generated method stub

    }
}

IpUtil类

package util;

/**
 * @Auther: raven
 * @Date: 2019/12/9 14:06
 * @Description:
 */



import javax.servlet.http.HttpServletRequest;
import java.net.*;
import java.util.Enumeration;


public class IpUtils {
    private static final String LOCAL_IP = "127.0.0.1";

    public static String getIpAddr(HttpServletRequest request) {
        if (request == null) {
            return "unknown";
        }
        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("X-Forwarded-For");
        }
        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("X-Real-IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }

        return "0:0:0:0:0:0:0:1".equals(ip) ? LOCAL_IP : ip;
    }

    public static boolean internalIp(String ip) {
        boolean res = false;
        byte[] addr = textToNumericFormatV4(ip);
        if (addr != null && ip != null) {
            res = internalIp(addr) || LOCAL_IP.equals(ip);
        }
        return res;
    }

    private static boolean internalIp(byte[] addr) {
        final byte b0 = addr[0];
        final byte b1 = addr[1];
        // 10.x.x.x/8
        final byte SECTION_1 = 0x0A;
        // 172.16.x.x/12
        final byte SECTION_2 = (byte) 0xAC;
        final byte SECTION_3 = (byte) 0x10;
        final byte SECTION_4 = (byte) 0x1F;
        // 192.168.x.x/16
        final byte SECTION_5 = (byte) 0xC0;
        final byte SECTION_6 = (byte) 0xA8;
        boolean flag = false;
        switch (b0) {
            case SECTION_1:
                flag = true;
                break;
            case SECTION_2:
                if (b1 >= SECTION_3 && b1 <= SECTION_4) {
                    flag = true;
                }
                break;
            case SECTION_5:
                if (b1 == SECTION_6) {
                    flag = true;
                }
                break;
            default:
                break;
        }
        return flag;
    }

    /**
     * 将IPv4地址转换成字节
     *IPv4地址
     * @param text
     * @return byte 字节
     */
    public static byte[] textToNumericFormatV4(String text) {
        if (text.length() == 0) {
            return null;
        }

        byte[] bytes = new byte[4];
        String[] elements = text.split("\\.", -1);
        try {
            long l;
            int i;
            switch (elements.length) {
                case 1:
                    l = Long.parseLong(elements[0]);
                    if ((l < 0L) || (l > 4294967295L))
                        return null;
                    bytes[0] = (byte) (int) (l >> 24 & 0xFF);
                    bytes[1] = (byte) (int) ((l & 0xFFFFFF) >> 16 & 0xFF);
                    bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                    bytes[3] = (byte) (int) (l & 0xFF);
                    break;
                case 2:
                    l = Integer.parseInt(elements[0]);
                    if ((l < 0L) || (l > 255L))
                        return null;
                    bytes[0] = (byte) (int) (l & 0xFF);
                    l = Integer.parseInt(elements[1]);
                    if ((l < 0L) || (l > 16777215L))
                        return null;
                    bytes[1] = (byte) (int) (l >> 16 & 0xFF);
                    bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                    bytes[3] = (byte) (int) (l & 0xFF);
                    break;
                case 3:
                    for (i = 0; i < 2; ++i) {
                        l = Integer.parseInt(elements[i]);
                        if ((l < 0L) || (l > 255L))
                            return null;
                        bytes[i] = (byte) (int) (l & 0xFF);
                    }
                    l = Integer.parseInt(elements[2]);
                    if ((l < 0L) || (l > 65535L))
                        return null;
                    bytes[2] = (byte) (int) (l >> 8 & 0xFF);
                    bytes[3] = (byte) (int) (l & 0xFF);
                    break;
                case 4:
                    for (i = 0; i < 4; ++i) {
                        l = Integer.parseInt(elements[i]);
                        if ((l < 0L) || (l > 255L))
                            return null;
                        bytes[i] = (byte) (int) (l & 0xFF);
                    }
                    break;
                default:
                    return null;
            }
        } catch (NumberFormatException e) {
            System.out.println("数字格式化异常"+e);
            return null;
        }
        return bytes;
    }

    public static String getLocalIP() {
        String ip = "";
        if (System.getProperty("os.name").toLowerCase().startsWith("windows")) {
            InetAddress addr;
            try {
                addr = InetAddress.getLocalHost();
                ip = addr.getHostAddress();
            } catch (UnknownHostException e) {
                System.out.println("获取失败"+e);
            }
            return ip;
        } else {
            try {
                Enumeration<?> e1 = (Enumeration<?>) NetworkInterface
                    .getNetworkInterfaces();
                while (e1.hasMoreElements()) {
                    NetworkInterface ni = (NetworkInterface) e1.nextElement();
                    if (!ni.getName().equals("eth0")) {
                        continue;
                    } else {
                        Enumeration<?> e2 = ni.getInetAddresses();
                        while (e2.hasMoreElements()) {
                            InetAddress ia = (InetAddress) e2.nextElement();
                            if (ia instanceof Inet6Address)
                                continue;
                            ip = ia.getHostAddress();
                            return ip;
                        }
                        break;
                    }
                }
            } catch (SocketException e) {
                System.out.println("获取失败"+e);
            }
        }
        return "";
    }
}

站点图：

总结

如果有人想窃取你的数据，如上配置之后，就可以用过滤器过滤掉高频率访问的ip了。但是人外有人天外有天，如果有人拿动态ip的话，那我们又该如何防范呢？