场景

有的时候我们需要获取客户端的真实ip，用来实现ip白名单，和黑名单的配置!

ip工具类如下

package com.meeno.framework.utils;

import javax.servlet.http.HttpServletRequest;

/**
 * @Auther: Wzq
 * @Date: 2019/3/14 14:53
 * @Description: 天青色等烟雨，而我在等你.. -- IpUtil
 */
public class IpUtil {



    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     *
     * @return ip
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        System.out.println("x-forwarded-for ip: " + ip);
         if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if( ip.indexOf(",")!=-1 ){
                ip = ip.split(",")[0];
            }
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
            System.out.println("Proxy-Client-IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
            System.out.println("WL-Proxy-Client-IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
            System.out.println("HTTP_CLIENT_IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            System.out.println("HTTP_X_FORWARDED_FOR ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
            System.out.println("X-Real-IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
            System.out.println("getRemoteAddr ip: " + ip);
        }
        System.out.println("获取客户端ip: " + ip);
        return ip;
    }

}