1.通过方法签名可以直接获取  HttpServletRequest，然后获取请求头信息

2.也可以通过  RequestContextHolder  来获取，具体方式如下

　　　　 ServletRequestAttributes attrs = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attrs.getRequest();
        String x =  request.getHeader("x");