<FORM METHOD = "post" ACTION = "uploadfile.htm" ENCTYPE = "multipart/form-data" CLASS = "form_view_type">

<input type="hidden" name="taskID" value="13">
Upload New File: 
<INPUT TYPE = "file" NAME = "fPath">
  
<INPUT TYPE = "submit" NAME = "Submit" VALUE = "Go">

</FORM>

 import  org.apache.commons.fileupload.DiskFileUpload;
 import  org.apache.commons.fileupload.FileItem;
 import  org.apache.commons.fileupload.FileItemFactory;
 import  org.apache.commons.fileupload.FileUpload;
 import  org.apache.commons.fileupload.FileUploadException;

 public   class  uploadfile
         extends  HttpServlet
{
    private   static   final  String CONTENT_TYPE = "text/html; charset=windows-1251";

   //Initialize global variables
    public   void  init()
            throws  ServletException
   {
   }



   //Process the HTTP Get request
    public   void  doGet(HttpServletRequest request, HttpServletResponse response)
            throws  ServletException, IOException
   {
      doPost(request, response);
   }



   //Process the HTTP Post request
    public   void  doPost(HttpServletRequest request, HttpServletResponse response)
            throws  ServletException, IOException
   {

      // taskID
       int  taskID;
       try 
      {
         taskID = Integer.parseInt(request.getParameter("taskID"));
      }
       catch (NumberFormatException e)
      {
         taskID =  0 ;
      }

      // ----------------------------------

      PrintWriter out = response.getWriter();

       try 
      {

         FileUpload fup =  new  FileUpload();
          boolean  isMultipart = FileUpload.isMultipartContent(request);
         // Create a new file upload handler

         out.println(isMultipart);
         DiskFileUpload upload =  new  DiskFileUpload();

         // Parse the request
         List items = upload.parseRequest(request);

         Iterator iter = items.iterator();
          while (iter.hasNext())
         {

            FileItem item = (FileItem)iter.next();

             if (item.isFormField())
            {
               out.println("its a field");
            }
             else 
            {
               out.println("its a file");
               out.println(item.getName());
               File cfile =  new  File(item.getName());
               File tosave =  new  File(getServletContext().getRealPath("/"), cfile.getName());
               item.write(tosave);
            }
         }

      }
       catch (Exception ex)
      {
         out.println(ex);
      }

      out.close();

   }


   //Clean up resources
    public   void  destroy()
   {
   }
}

exception 

javax.servlet.ServletException: Servlet execution threw an exception


root cause 

java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream
	org.apache.commons.fileupload.DefaultFileItemFactory.createItem(DefaultFileItemFactory.java: 102 )
	org.apache.commons.fileupload.FileUploadBase.createItem(FileUploadBase.java: 500 )
	org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java: 367 )
	org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java: 268 )
	main.uploadfile.doPost(uploadfile.java: 100 )
	javax.servlet.http.HttpServlet.service(HttpServlet.java: 709 )
	javax.servlet.http.HttpServlet.service(HttpServlet.java: 802 )

         FileUpload fup =  new  FileUpload();
          boolean  isMultipart = FileUpload.isMultipartContent(request);
         // Create a new file upload handler

         out.println(isMultipart);

         DiskFileUpload upload =  new  DiskFileUpload();

         // Parse the request
         List items = upload.parseRequest(request);

       ....
               File cfile =  new  File(item.getName());
               File tosave =  new  File(getServletContext().getRealPath("/"), cfile.getName());
               item.write(tosave);
               
                byte [] rgb = item.get();
               
                if  (rgb !=  null )
               {

                   response.reset();
                   response.setContentType("image/jpeg");
                   response.setContentLength(rgb.length);
                   ServletOutputStream stream = response.getOutputStream();
                   stream.write(rgb);
                   stream.flush();
                   stream.close();
               }

response.setContentType("image/gif");