Well, for starters you don't map a JSP page in the url-pattern. Also, the servlet-class only exists in the <servlet> definition, not in the <servlet-mapping>. Third, your UploadFile is not specified as being in a package (com.bla.UploadFile). Forth, you have specified your servlet-class as Main in the <servlet> tag when it should be UploadFile. And Fifth, the way you map your <servlet> tag to your <servlet-mapping> tag is by the <servlet-name> and have have specified 2 different names. Your web.xml should look closer to something like this below.
Keep in mind that your <url-patter> can be pretty much anything you want, so long as you map it correctly in your <form> element of your JSP page or call it correctly from another servlet.
And then in Main.jsp's <form> element, you would have something like