1：request.getRemoteAddr()
2：如果请求的客户端使用了nginx 等反向代理发送请求的时候：就不能获取到真是的ip地址了：如：将http://192.168.1.110:2046/ 的URL反向代理为http://www.xxx.com/ 的URL时，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。
3：解决：
public String getRemoteHost(javax.servlet.http.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.getRemoteAddr();
}
return ip.equals("0:0:0:0:0:0:0:1")?"127.0.0.1":ip;
}