Java获取IP地址:request.getRemoteAddr()警惕
if (request.getHeader("x-forwarded-for") == null) {
return request.getRemoteAddr();
}
return request.getHeader("x-forwarded-for");
}
可是当我访问http://www.xxx.com/index.jsp/ 时,返回的IP地址始终是unknown,也并不是如上所示的127.0.0.1 或 192.168.1.110 了,而我访问http://192.168.1.110:2046/index.jsp 时,则能返回客户端的真实IP地址,写了个方法去验证。原因出在了Squid上。squid.conf
的配制文件 forwarded_for 项默认是为on,如果 forwarded_for 设成了 off 则:X-Forwarded-For: unknown
于是可得出获得客户端真实IP地址的方法二:
2 String ip = request.getHeader( " x-forwarded-for " );
3 if (ip == null || ip.length() == 0 || " unknown " .equalsIgnoreCase(ip)) {
4 ip = request.getHeader( " Proxy-Client-IP " );
5 }
6 if (ip == null || ip.length() == 0 || " unknown " .equalsIgnoreCase(ip)) {
7 ip = request.getHeader( " WL-Proxy-Client-IP " );
8 }
9 if (ip == null || ip.length() == 0 || " unknown " .equalsIgnoreCase(ip)) {
10 ip = request.getRemoteAddr();
11 }
12 return ip;
13 }
可是,如果通过了多级反向代理的话,X-Forwarded-For的值并不止一个,而是一串Ip值,究竟哪个才是真正的用户端的真实IP呢?
答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。
如:
X-Forwarded-For:192.168.1.110, 192.168.1.120, 192.168.1.130, 192.168.1.100
用户真实IP为: 192.168.1.110
说明:按这种方法不一定100%准,网上很多人提到要准确的话必须做一个客户端空间,如applet。
转载地址http://www.cnblogs.com/panjun-Donet/archive/2009/08/12/1544274.html
不希望看到冗长的X-Forwarded-For 那么可以转化成下面的程序
public String getIpAddr(HttpServletRequest request) {
String ip = request.getHeader("x-forwarded-for");
// if(ip == null){
// ip = request.getRemoteAddr();
// }
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.getRemoteAddr();
}
if (ip == null || ip.length() == 0 || " unknown ".equalsIgnoreCase(ip)) {
ip = request.getHeader("HTTP_X_FORWARDED_FOR");
}
return ip;
}