ZK & Struts2获得真实 IP 地址

/** * 得到真实的IP地址 * @param request * @return */public String getIpAddr() {   HttpServletRequest request = null;   if(Sessions.getCurrent() != null){//ZK获得Request   ServletContext sc = (ServletContext) Sessions.getCurrent().getWebApp().getNativeContext();   request = (HttpServletRequest) Executions.getCurrent().getNativeRequest();   }else{//Struts2获得Request   request = ServletActionContext.getRequest();   }       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;}

?