java中相对路径与绝对路径的区别

if(u!=null){System.out.println("拦截器验证登录");return true;}String local = request.getServerName()+":";//：获取服务器名，localhost；int dk = request.getServerPort();//：获取服民英王务器端口号，8080；response.sendRedirect("dealer_login.do");return false;

拦截器中得重定向，也是相对于当前路径下得相对路径；

获取根路径表达式，${pageContext.request.contextPath}

文件上传

<%String path = request.getContextPath();String basePath = request.getScheme() + "://"+ request.getServerName() + ":" + request.getServerPort()+ path + "/";%>

  基本信息