@Override
    public void init(FilterConfig arg0) throws ServletException {
        // TODO Auto-generated method stub
        logger.info("======begin web context====");
        ServletContext context=arg0.getServletContext();
        String webroot=context.getContextPath()+"/WebContent/";
        context.setAttribute("webroot", webroot);
        logger.info("webroot:"+webroot);
        
    }