java获取客户端IP

 public 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;

   }