HttpServletRequst 获取客户端真实IP

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,Squid等反向代理软件就不能获取到客户端的真实IP地址了。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。有时候，使用了Squid，则会发现IP地址始终是unknown，由于squid.conf的配置文件中，forwarded_for
项默认是为on，如果 forwarded_for 设成了 off，则：X-Forwarded-For: unknown。而且，对于IPv6的情况，还要特殊处理 

ip.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : ip;

因此，获取客户端IP的方法如下：
public static String getIpAddress(HttpServletRequest request) {
String ip = request.getHeader("x-forwarded-for");
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("Proxy-Client-IP");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("WL-Proxy-Client-IP");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("HTTP_CLIENT_IP");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("HTTP_X_FORWARDED_FOR");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
ip = request.getRemoteAddr();
}

//return ip;
return ip.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : ip;
}
转载自：
http://www.cnblogs.com/icerainsoft/p/3584532.html http://blog.csdn.net/xiaokui_wingfly/article/details/45888381