Howdy Richard,
We do some of both--there *is* a basic app that is modified and changed throughout the book, but our
philosophy is that we pick whatever examples will best make the points that you most need to learn for a given topic, and that have the *least* amount of cognitive overhead. In other words, we don't want you to spend any brain bandwidth on figuring out what the heck the *example* is about, so that you can devote the most brain power and memorization to the actual thing you are supposed to be learning.
The book does have a LOT of code. If you've seen the EJB book, this
Servlets &
JSP book is substantially different in the amount of code and examples. But there isn't a huge project that you're required to keep up with throughout the book.
cheers,
Kathy