获取用户电脑请求真实IP

   用户在访问网站时，需要记录用户电脑请求的IP,由于nginx代理、前后端分离分机部署等原因，有时候可能获取IP非用户真实请求IP，可能是代理IP，在网上找了些文档发现也不好用，下面是我这边经过实践可以使用的代码，可做参考：

import lombok.extern.slf4j.Slf4j;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

@Slf4j
public class IpUtil {

    /**
     * 获取客户端IP地址
     * 注意本地测试访问项目地址时，浏览器请求不要用 localhost，请用本机IP；否则，取不到 IP
     *
     * @return String 真实IP地址
     */
    public static String getClientIpAddress(HttpServletRequest request) {
        // 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实IP地址
        String headerName = "x-forwarded-for";
        String ip = request.getHeader(headerName);
        if (null != ip && 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,它们按照英文逗号','分割
            if (ip.indexOf(",") != -1) {
                ip = ip.split(",")[0];
            }
        }
        if (checkIp(ip)) {
            headerName = "Proxy-Client-IP";
            ip = request.getHeader(headerName);
        }
        if (checkIp(ip)) {
            headerName = "WL-Proxy-Client-IP";
            ip = request.getHeader(headerName);
        }
        if (checkIp(ip)) {
            headerName = "HTTP_CLIENT_IP";
            ip = request.getHeader(headerName);
        }
        if (checkIp(ip)) {
            headerName = "HTTP_X_FORWARDED_FOR";
            ip = request.getHeader(headerName);
        }
        if (checkIp(ip)) {
            headerName = "X-Real-IP";
            ip = request.getHeader(headerName);
        }
        if (checkIp(ip)) {
            headerName = "remote addr";
            ip = request.getRemoteAddr();
            // 127.0.0.1 ipv4, 0:0:0:0:0:0:0:1 ipv6
            if ("127.0.0.1".equals(ip) || "0:0:0:0:0:0:0:1".equals(ip)) {
                //根据网卡取本机配置的IP
                InetAddress inet = null;
                try {
                    inet = InetAddress.getLocalHost();
                } catch (UnknownHostException e) {
                    log.error("HttpCusAccessUtil#getClientIpAddress 获取客户端IP地址异常", e);
                }
                ip = inet.getHostAddress();
            }
        }
        return ip;
    }

    private static boolean checkIp(String ip) {
        if (null == ip || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            return true;
        }
        return false;
    }
}