public static String getUserRealIP(HttpServletRequest request) throws UnknownHostException {
      String ip = "";
      // 有的user可能使用代理，为处理用户使用代理的情况，使用x-forwarded-for
      if (request.getHeader("x-forwarded-for") == null) {
            ip = request.getRemoteAddr();
      } else {
      ip = request.getHeader("x-forwarded-for");
}
if ("127.0.0.1".equals(ip)) {
      // 获取本机真正的ip地址
      ip = InetAddress.getLocalHost().getHostAddress();
}
return ip;
}

import java.util.*;
import java.net.*;
public class getMyIP
{
      public static void main(String[] args) {
            String ip = null;
            String host = null;
            try{
                  InetAddress ia = InetAddress.getLocalHost();
                  host = ia.getHostName();//获取计算机名字
                  ip = ia.getHostAddress();//获取IP
            } catch(UnknownHostException e) {
                  e.printStackTrace();
            }
            System.out.println(host);
            System.out.println(IP);
      }
}