The best debugging tool for servlet/jsp is the programmer's brain. (sorry, I just had to say that - one of these days I will finish my article of
servlet debugging for the newsletter, really I will, Sheriff - stop looking at me like that.)
Ahem - anyway here are some the point that will end up in this future article:
1. The servlet/JSP environment is horrible for debugging because so many things can go wrong, and you may have multiple threads. Therefore,
test as much as you can outside the servlet
JSP environment. This means that as little code as possible should be in a servlet class. JavaBeans are your friends.
2. Make good use of exceptions - NEVER do a catch(Exception e){} - you are throwing away information. No reason not to invent your own Exception that carries information specific to your application.
3. Double-check the actual content being sent in a request by snooping on the request/response text. I can point you to a utility for this.
Bill