Chapter 11. Business rules using JBoss Drools

Decisions, in the form of rules, represent the brains behind your business. Whether you sell products or services, engage in a nonprofit venture, or even make movies, every step along the way involves decisions. Some decisions are more strategic in nature, such as deciding when to develop and introduce a new product. Others are more tactical or operational in nature, such as deciding whether to extend credit terms to a new customer. The quality of the strategic decisions impacts the long-term viability of your organization; the operational ones greatly influence bottom-line profitability.

This chapter and the next will focus on how to use a rules engine for centrally managing operational decisions in the context of a SOA environment. We’ll describe the benefits and drivers behind adopting a rules engine, explore its common characteristics, introduce the Drools rules engine, and describe the features and functionality of Drools using a Hello World example (the next chapter will cover implementation strategies for using Drools). By the conclusion of this chapter, you’ll understand why a rules engine represents such a powerful addition to SOA.

11.1. Understanding business rules

11.2. Introducing Drools

11.3. Drools Rule Language (DRL) overview

11.4. Drools header elements

11.5. Defining rules in Drools

11.6. Querying facts in Drools

11.7. Drools RuleFlow for rule orchestration

11.8. Alternatives to using Drools Rule Language

11.9. Summary