public static String getIp2(HttpServletRequest request) {
String ip = request.getHeader("X-Forwarded-For");
if(StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)){
//多次反向代理後會有多個ip值，第一個ip才是真實ip
int index = ip.indexOf(",");
if(index != -1){
return ip.substring(0,index);
}else{
return ip;
}
}
ip = request.getHeader("X-Real-IP");
if(StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)){
return ip;
}
return request.getRemoteAddr();
}

轉http://www.cnblogs.com/ITtangtang/p/3927768.html