在JSP里,獲取客戶端的IP地址的方法是:request.getRemoteAddr(),這種方法在大部分情況下都是有效的。但是在通過了 Apache,Nagix等反向代理軟件就不能獲取到客戶端的真實IP地址了。如果使用了反向代理軟件,用 request.getRemoteAddr()方法獲取的IP地址是:127.0.0.1或 192.168.1.110,而並不是客戶端的真實IP。
經過代理以后,由於在客戶端和服務之間增加了中間層,因此服務器無法直接拿到客戶端的 IP,服務器端應用也無法直接通過轉發請求的地址返回給客戶端。但是在轉發請求的HTTP頭信息中,增加了X-FORWARDED-FOR信息。用以跟蹤原有的客戶端 IP地址和原來客戶端請求的服務器地址。
舉例來說,當我們訪問口百度首頁baidu.jsp時,其實並不是我們瀏覽器真正訪問到了服務器上的baidu.jsp 文件,而是先由代理服務器Nagix去訪問baidu.jsp ,代理服務器再將訪問到的結果返回給我們的瀏覽器,因為是代理服務器去訪問baidu.jsp的,所以baidu.jsp中通過 request.getRemoteAddr()的方法獲取的IP實際上是代理服務器的地址,並不是客戶端的IP地址。
獲取請求主機IP地址,如果通過代理進來,則透過防火牆獲取真實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); /** * 獲取請求主機IP地址,如果通過代理進來,則透過防火牆獲取真實IP地址; * * @param request * @return * @throws IOException */ public final static String getIpAddress(HttpServletRequest request) throws IOException { // 獲取請求主機IP地址,如果通過代理進來,則透過防火牆獲取真實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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