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;

 package com.utils;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import javax.servlet.http.HttpServletRequest;
 import java.io.IOException;

 /**
  * 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;
  *
  */
 public final class NetworkUtil {

     private static final Logger LOG = LoggerFactory.getLogger(NetworkUtil.class);

     public final static String getIpAddress(HttpServletRequest request)
             throws IOException {

         String ip = request.getHeader("X-Forwarded-For");

 //        LOG.info("getIpAddress(HttpServletRequest) - X-Forwarded-For - String ip= {}" ,ip);

         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             if (ip == null || ip.length() == 0
                     || "unknown".equalsIgnoreCase(ip)) {
                 ip = request.getHeader("Proxy-Client-IP");
 //                LOG.info("getIpAddress(HttpServletRequest) - Proxy-Client-IP - String ip= {}" , ip);
             }
             if (ip == null || ip.length() == 0
                     || "unknown".equalsIgnoreCase(ip)) {
                 ip = request.getHeader("WL-Proxy-Client-IP");
 //                LOG.info("getIpAddress(HttpServletRequest) - WL-Proxy-Client-IP - String ip= {}" , ip);
             }
             if (ip == null || ip.length() == 0
                     || "unknown".equalsIgnoreCase(ip)) {
                 ip = request.getHeader("HTTP_CLIENT_IP");
 //                LOG.info("getIpAddress(HttpServletRequest) - HTTP_CLIENT_IP - String ip= {}" , ip);
             }
             if (ip == null || ip.length() == 0
                     || "unknown".equalsIgnoreCase(ip)) {
                 ip = request.getHeader("HTTP_X_FORWARDED_FOR");
 //                LOG.info("getIpAddress(HttpServletRequest) - HTTP_X_FORWARDED_FOR - String ip= {}" , ip);
             }
             if (ip == null || ip.length() == 0
                     || "unknown".equalsIgnoreCase(ip)) {
                 ip = request.getRemoteAddr();
 //                LOG.info("getIpAddress(HttpServletRequest) - getRemoteAddr - String ip= {}" , ip);
             }
         } else if (ip.length() > 15) {
             String[] ips = ip.split(",");
             for (int index = 0; index < ips.length; index++) {
                 String strIp = (String) ips[index];
                 if (!("unknown".equalsIgnoreCase(strIp))) {
                     ip = strIp;
                     break;
                 }
             }
         }
         return ip;
     }
 }