Welcome files are a list of partial URLs specified in <welcome-file-list> in web.xml, and they are used to complete un-mapped URLs that correspond to directories. For example, if the URL http://host/mywebapp/directory/ is not handled by any controller, the application server will try the URL http://host/mywebapp/diretory/index.jsp (assuming index.jsp is one of the welcome files) and see if that URL is handled.

I noticed that many students are not using welcome files in their homework projects. This is obviously not good in practice, and it's even more irritating in grading because I have to look through the controllers and guess whether /user/login.html or /event/myevents.html is supposed to be the front page. So from now on, use of welcome file is required in all homework assignments, including HW5. In particular, the URL http://<host>/<webapp>/ (where <webapp> is the name of your application, e.g. envite) should either be the front page of your application, or has a link to the front page of your application.