JSP submitted to servlet report 404 error Resolution (Webroot) _JSP programming

The first time to write things with JSP, in the Webroot subfolder to write JSP, when submitted to the servlet times 404 error, the old thought is a child file problem, in fact, is not.

The fact is that the students delete this code to me, the JSP file can not find the root directory,

Copy Code code as follows:

<%
String path = Request.getcontextpath ();
String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";
%>
<base href= "<%=basePath%>" >

Oh, this situation is very wonderful, for the novice is simply egg pain home ah.