problem regarding File Uploading on Server.

hi friends... i am new to JSP.
I am trying to upload a file from user's machine to server. I am useing JSP and apache Tomcat 5.0
Here is my code.
------------------------

<html>
<body>
<%@ page language="java" import="org.apache.commons.fileupload.*,org.apache.commons.fileupload.servlet.ServletFileUpload, org.apache.commons.fileupload.disk.*, org.apache.commons.io.*, java.util.*, java.io.File, java.lang.Exception" %>
<%
if(ServletFileUpload.isMultipartContent(request))
{
// Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();
 // maximum size that will be stored in memory
 factory.setSizeThreshold(4096);
 // the location for saving data that is larger than getSizeThreshold()
 // Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
 // maximum size before a FileUploadException will be thrown
 upload.setSizeMax(1000000);
 
// Parse the request
List /* FileItem */ items = upload.parseRequest(request);
 
// Process the uploaded items
Iterator iter = items.iterator();
while (iter.hasNext()) 
{
 FileItem item = (FileItem) iter.next();
 
 if (item.isFormField()) 
{
 out.println("item.getString()");
 } 
else 
{
%>
Uploaded File Info: 
Content type: <%= item.getContentType() %> 
Field name: <%= item.getFieldName() %> 
File name: <%= item.getName() %> 
File size: <%= item.getSize() %> 
<%
if (item.getSize() > 0)
{
 //String dirName = "c:\mydir\";
//String dirName = getServletContext().getRealPath("WEB-INF")+"/file_uploads/";
String dirName = "/file_uploads/";
 
 File saveTo = new File(dirName +item.getName());

try 
{
 item.write(saveTo);
 }
 
catch (Exception e)
{
%>
An error occurred when we tried to save the uploaded file.
<%
 }/*catch*/}//if
}
 
}
}
%>

<body>
</html>

-----------------------------------------------------
the error i am getting---
exception

javax.servlet.ServletException: javax/servlet/http/HttpServletRequest
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:867)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:800)
org.apache.jsp.noticeboard.upload_jsp._jspService(upload_jsp.java:139)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:133)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:311)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)

root cause

java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
org.apache.commons.fileupload.servlet.ServletFileUpload.isMultipartContent(ServletFileUpload.java:68)
org.apache.jsp.noticeboard.upload_jsp._jspService(upload_jsp.java:55)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:133)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:311)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)

---------------------------
please help me....
[BSouther: Added UBB CODE tags]

[ March 18, 2007: Message edited by: Ben Souther ]
[ March 18, 2007: Message edited by: Bear Bibeault ]

"vikash.tony sharma.sharma",

There aren't many rules that you need to worry about here on the Ranch, but one that we take very seriously regards the use of proper names. Please take a look at the JavaRanch Naming Policy and adjust your display name to match it.

In particular, your display name must be a first and a last name separated by a space character, and must not be obviously fictitious.

Thanks!
bear
JavaRanch Sheriff

hi friend! just put jar files regarding jsp, i mean jsp...jar files in common folder

thanks ramesh...
but can you elaborate what exactly do you mean by copying jar files in appropriate folder...

well i am on this project for about 3 weeks. i have completed few modules on jsp which includes access to the database which works fine.

i have downloaded Apache fileupload jar files and copied them in tomcat's common/lib folder.

please suggest me something..

sorry RAJESH.M
i mis spelled your name.. sorry for that...