This book explains everything you need to know about Java servlet programming. The first five chapters cover the basics: what servlets are, what they do, and how they work. The following eight chapters are where the true meat is--they explore the things you are likely to do with servlets. You'll find numerous examples, several suggestions, a few warnings, and even a couple of true hacks that somehow made it past technical review.
http: / / www.unix.com.ua / orelly / java-ent / servlet / index.htm
The second edition of Core Servlets and JavaServer Pages is now available for free access in PDF. See links below. Readers of the older edition can still access the first edition here.
http: / / pdf.coreservlets.com /
Addison-Wesley and Developmentor have provided TheServerSide.com with the entire book of Servlets and JSP the J2EE Web Tier for free download. Servlets and JSP the J2EE Web Tier is a book authored by Jayson Falkner and Kevin Jones about the latest in Servlets and JSP.
http: / / www.theserverside.com / tt / books / addisonwesley / ServletsJSP / index.tss