Let say my first application, I tried to put the .class file inside /apps/servlet then I tested the URL but I got HTTP 404 error.
I also tried putting it under /apps/WEB-INF/classes but it also gives me the same error.
Classes should go under /WEB-INF/classes, following package notation. So if the class is bar.baz.MyFirstServlet.class its directory location would be /WEB-INF/classes/bar/baz/MyFirstServlet.class.