Suppose that when a URL contains the word UserLogin, you want it to invoke the login.jsp file. You can use the entry in web.xml to accomplish this.

The user will never know that a .jsp page is actually being used here for login purposes, which can prove to be a valuable security measure.

You simply need to provide a mapping for the file in the tag as below.

        UserLogin        /login.jsp	UserLogin	/UserLogin