Book Image

Drools JBoss Rules 5.X Developer's Guide

By : Michal Bali
Book Image

Drools JBoss Rules 5.X Developer's Guide

By: Michal Bali

Overview of this book

<p>Writing business rules has always been a challenging task. Business rules tend to change often leading to a maintenance nightmare. This book shows you various ways to code your business rules using Drools, the open source Business Rules Management System.<br /><br />Drools JBoss Rules 5.X Developer's Guide shows various features of the Drools platform by walking the reader through several real-world examples. Each chapter elaborates on different aspects of the Drools platform. The reader will also learn about the inner workings of Drools and its implementation of the Rete algorithm.<br /><br />The book starts with explaining rule basics, then builds on this information by going through various areas like human readable rules, rules for validation, and stateful rules, using examples from the banking domain. A loan approval process example shows the use of the jBPM module. Parts of a banking fraud detection system are implemented with the Drools Fusion module which is the complex event processing part of Drools. Finally, more technical details are shown detailing the inner workings of Drools, the implementation of the ReteOO algorithm, indexing, node sharing, and partitioning.</p>

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Drools JBoss Rules 5.X Developer's Guide
Michal Bali
May, 2013 | 338 pages
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Table of Contents (22 chapters)
Drools JBoss Rules 5.X Developer's Guide
Drools JBoss Rules 5.X Developer's Guide
Credits
Credits
About the Author
About the Author
About the Reviewers
About the Reviewers
www.PacktPub.com
www.PacktPub.com
Preface
Preface
Free Chapter
1
Programming Declaratively
Programming Declaratively
Problems with traditional approaches
The solution
Drools
Summary
2
Writing Basic Rules
Writing Basic Rules
Rule basics
Rule syntax
Summary
3
Validating
Validating
Banking domain model
Problem definition
Analysis
Design
Validation package
Implementation
Validation service
Summary
4
Transforming Data
Transforming Data
Process overview
Getting the data
Writing transformation rules
Transformation results
Implementation of the data loading
Summary
5
Creating Human-readable Rules
Creating Human-readable Rules
Domain-specific language
The decision tables
jBPM
Summary
6
Working with Stateful Session
Working with Stateful Session
StatefulKnowledgeSession
Validation using stateful session
Summary
7
Complex Event Processing
Complex Event Processing
CEP and ESP
Drools Fusion
Fraud detection
Summary
8
Defining Processes with jBPM
Defining Processes with jBPM
Loan approval service
Loan approval process
Summary
9
Building a Sample Application
Building a Sample Application
Users
Architecture
Technologies used
Business logic
Design
Configuration
Repositories
Validation
Loan approval
Summary
10
Testing
Testing
Writing unit tests for rules
Rule integration testing
Rule acceptance testing
Static analysis of rules
Troubleshooting techniques
Summary
11
Integrating
Integrating
Dynamic KnowledgeBase loading
External artifact building
Drools Camel server
Spring framework integration
Standards
Summary
12
Learning about Performance
Learning about Performance
Rete algorithm
Node sharing
Node indexing
Left and right unlinking
The KnowledgeBase partitioning
Summary
Setting Up the Development Environment
Setting Up the Development Environment
Environment setup
Creating Custom Operators
Creating Custom Operators
Summary
Dependencies of Sample Application
Dependencies of Sample Application
Index
Index

Implementation of the data loading

In this section we'll look closer at getting the data from the legacy system. If you're not interested in actually trying out this example, you can skip this section.

Database setup

The data can come from various sources – database, XML, CSV, and so on. Our application will pull data from a database; however, it shouldn't be a problem to work with any other data source. The table structure looks as follows:

CREATE TABLE  `droolsBook`.`customer` ( 
  `customer_id` bigint(20) NOT NULL, 
  `first_name` varchar(255) NOT NULL, 
  `last_name` varchar(255) NOT NULL, 
  `email` varchar(255) NOT NULL, 
  PRIMARY KEY  (`customer_id`) 
)

Code listing 24: Table structure for legacy customers in a MySQL Database 

CREATE TABLE  `droolsBook`.`address` ( 
  `address_id` bigint(20) NOT NULL default '0', 
  `parent_id` bigint(20) NOT NULL, 
  `street` varchar(255) NOT NULL, 
  `area` varchar(255) NOT NULL, 
  `town` varchar(255) NOT NULL, 
  `country` varchar(255) NOT NULL,...
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