Rule-based systems are rapidly growing in importance. That's partly due to the increased focus on business rules in enterprise computing, but rule-based systems have multiple applications. Expert systems for evaluating insurance claims and picking stocks. Network intrusion detection. E-commerce. Even gaming. Unfortunately, most books on rule-based programming have been largely theoretical -- until now. Jess in Action is a relentlessly practical, accessible, project-based guide to using Jess, the popular rule-based programming environment for Java. Authoritative, too: The author, Ernest Friedman-Hill, created Jess.
He begins by introducing the fundamental ideas behind rule-based systems and indicating what they're good for. Next, you'll walk through the fundamentals of working with Jess: basic syntax and control structures; defining functions and fine-tuning their behavior; creating Java objects, calling Java methods, accessing Java member data; and more. You'll learn how to write rules in Jess, and create and manage the data those rules can act on -- a.k.a. Jess's "working memory" or "fact base."
The heart of the book is its five application projects. You'll start simple, with an app that helps users figure out what tax forms they need and introduces you to the basics of knowledge engineering. You'll write a PC repair assistant that incorporates flowcharting and a graphical interface. You'll build a heating/air conditioning controller that interfaces with hardware and requires Java extensions to Jess. There's a complete e-commerce case study, plus coverage of representing rules as XML. All the examples can be downloaded from a companion web site, along with a binary version of Jess itself, free for noncommercial use. Bill Camarda
Bill Camarda is a consultant, writer, and web/multimedia content developer. His 15 books include Special Edition Using Word 2000 and Upgrading & Fixing Networks for Dummies, Second Edition.