获取IP工具类

public class IPUtils {

   /**
    * 获取IP地址
    * 
    * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
    * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
    */
   public static String getIpAddr(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 "0:0:0:0:0:0:0:1".equals(ip) ? "127.0.0.1" : ip;
   }

}