在JSP里,获取客户端的IP地址的方法是:request.getRemoteAddr(),这种方法在大部分情况下都是有效的。但是在通过了 Apache,Nagix等反向代理软件就不能获取到客户端的真实IP地址了。如果使用了反向代理软件,用 request.getRemoteAddr()方法获取的IP地址是:127.0.0.1或 192.168.1.110,而并不是客户端的真实IP。
经过代理以后,由于在客户端和服务之间增加了中间层,因此服务器无法直接拿到客户端的 IP,服务器端应用也无法直接通过转发请求的地址返回给客户端。但是在转发请求的HTTP头信息中,增加了X-FORWARDED-FOR信息。用以跟踪原有的客户端 IP地址和原来客户端请求的服务器地址。
举例来说,当我们访问口百度首页baidu.jsp时,其实并不是我们浏览器真正访问到了服务器上的baidu.jsp 文件,而是先由代理服务器Nagix去访问baidu.jsp ,代理服务器再将访问到的结果返回给我们的浏览器,因为是代理服务器去访问baidu.jsp的,所以baidu.jsp中通过 request.getRemoteAddr()的方法获取的IP实际上是代理服务器的地址,并不是客户端的IP地址。
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:
Class : NetworkUtil
package com.xindatai.common.util; import java.io.IOException; import javax.servlet.http.HttpServletRequest; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class NetworkUtil { /** * Logger for this class */ private static Logger logger = LoggerFactory.getLogger(NetworkUtil.class); /** * 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; * * @param request * @return * @throws IOException */ public final static String getIpAddress(HttpServletRequest request) throws 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 String ip = request.getHeader("X-Forwarded-For"); if (logger.isInfoEnabled()) { logger.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"); if (logger.isInfoEnabled()) { logger.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"); if (logger.isInfoEnabled()) { logger.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"); if (logger.isInfoEnabled()) { logger.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"); if (logger.isInfoEnabled()) { logger.info("getIpAddress(HttpServletRequest) - HTTP_X_FORWARDED_FOR - String ip=" + ip); } } if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { ip = request.getRemoteAddr(); if (logger.isInfoEnabled()) { logger.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; } }
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