获取真实ip地址

private 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 ip;      

}