I had the chance of reading the book Drools Jboss Rules 5.X Developer’s Guide, written by Michal Bali, and I wanted to share my thoughts about this.
This book is intended to show various features of the Drools plattform to be able to succeed on writing rules and use and integrate them in real world applications.
First of all, this book covers all the major topics every person interested in using Drools must read. This effectively transmits the general ideas of when, why and how the use of Drools Plattform will help someone to implement his system, and also when and why NOT it would be helpful, in a clear and easy to understand vocabulary and organization.
The first thing I noticed from this book is the good amount of examples it provides. Examples are really instructive, different scenarios and examples are shown. These examples are all covered by showing the rules, processes, models and services they need, and they all have unit tests showing exactly how they run, which makes them even more helpful for the reader, and will make him save a lot of time!
The most important topics are discussed: Drools Rules, JBPM 5, Complex Event Procesing, with some theoric introductions and a lot of real world information. I personally liked the way jBPM examples are shown in the book, that gives a great idea of how powerful can be using jBPM and rules together in the way the Drools project proposes.
Details are well covered. From how to write simple rules, with the different configurations, syntax options and features, to writing a real application, going through most common implementation and design details a drools developer will have to deal with. Pay attention to Notes, there are always important tips mentioned!
Lastly, I could say as a detail, that I would have liked to read more about the different strategies for storing the rules. Using Drools Guvnor (or not), which are the options and design ideas to take into consideration and most common decisions that must be taken about this.
In conclusion this is a must-read for everyone interested in using Drools project, and it provides useful information for beginners, intermediate and also advanced users of drools. Really recommended book!