Java Programming

When I run a website on localhost to upload an image, the servlet threw 2 exceptions:

java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream
org.apache.commons.fileupload.disk.DiskFileItemFactory.createItem(DiskFileItemFactory.java:196)
org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:358)
org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
com.ptc.smsfinder.Registratoin_Step4_Submit.doPost(Registratoin_Step4_Submit.java:41)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


root cause

java.lang.ClassNotFoundException: org.apache.commons.io.output.DeferredFileOutputStream
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
java.lang.ClassLoader.loadClassInternal(Unknown Source)
org.apache.commons.fileupload.disk.DiskFileItemFactory.createItem(DiskFileItemFactory.java:196)
org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:358)
org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
com.ptc.smsfinder.Registratoin_Step4_Submit.doPost(Registratoin_Step4_Submit.java:41)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

I use tomcat 6.0 and jdk1.6 and MyEclipse

I included commons-fileupload-1.2.1.jar in the project.

and

import org.apache.commons.fileupload.*;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.*;
import org.apache.commons.fileupload.disk.*;