JBoss Rules

Overview

The JBoss Rules is targeted at middleware application developers, with zero to moderate experience with rule technology. Developers who need to use rule technologies to manage their applications business logic, and integrate the rule engine with their application would get value from this course.

Further to this, application architects or advanced developers looking to improve approaches to business logic management in their applications would also find this course of value – it also serves as an introduction to rule based technologies.

Prerequisites

Pre-requisite skills for this course are:

• Basic Java competency
• Some understanding of what constitutes an inferencing rule engine versus a scripting engine
• Viewing of the Jboss Rules webinars and demos is recommended but not required
• Java EE specific experience is not required for the course, but students who need to know how to integrate with Java EE will need the appropriate experience

Course Outline

Intro to JBoss Drools

This module covers the background and history of rule engines, and what a rule and rule engine actually is, and what they are typically used for. The importance of declarative programming will be emphasized. This module also covers some core concepts such as pattern matching and forward chaining, and provides a quick overview of JBoss Drool features.

he Drools Rule Language

This module provides a fairly detailed introduction to the Drools Rule Language, including constraints, bindings, conditional elements, etc. This module also includes a discussion on the Drool API. A short lab is included that will provide experience in authoring and executing a rule, which will also show off the Drools IDE.

Domain Specific Languages

After this module students will be familiar with both domain specific languages which are alternative ways of capturing rules. A lab similar to the first lab will be performed to get comfortable with creating DSLs.

Rule formats

Decision Tables After this module students will be familiar with decision tables which are yet another way of capturing rules. A lab similar to the first two lab will be performed to provide familiarity with Decision Tables.

BRMS

This module introduces the Business Rules Management System (BRMS), a combination of a rule repository and a web GUI for authoring, importing, managing, and deploying rules. The module concludes with a lab that created rules using the BRMS Guided Rule Editor.

The RETE Algorithm

This module covers core concepts of a forward chaining engine. This will include an explanation of a basic non scalable inferencing algorithm (linear), before introducing the RETE algorithm. It will discuss how and when a RETE network is built, and how facts propagate through the network resulting in rules being activated. A lab will be performed to make some of the concepts more concrete.

Advanced Rule Language

This module covers advanced features of the Drools Rule Language, including additional conditional elements (from, collect, and accumulate), the use of the MVEL dialect, etc.

Execution Control

This module discusses several strategies for control the execution of rules, including the use of salience, agenda groups, and control facts.

Ruleflow

This module discusses an important strategy for control the execution of rules, namely ruleflow. With ruleflow, the rule author can sequence the execution of groups of rules using a graphical design tool. A lab will be performed that demonstrates the use of ruleflow.

Performance and Debugging

This module reviews several “best practices” for authoring rules, particularly when performance is a concern. This module also introduces the Drool IDE debugger. demonstrates the use of ruleflow.