So far four chapters of the book is available to the MEAP subscribers. The available chapters form most of the book's first part which intended to introduce OSGI to readers. The chapters have acheived the goal that authors set for them very well. I was well familiar with OSGI Module layer before reading the available four chapters and now I can certainly say that the content provided in these chapters are unique in the quality. Reading these chapters further enhanced my knowledge on OSGI Module layer and service layer. I recommend this book to every serious Java developer which is involved or will be involved with modular architecture in general and OSGI in particular.
The first chapter of every Mannig book that I read was some kind of introduction and was covering the background of the domain which book was going to cover. The OSGI in Action is not an exception and its first chapter explains why a framework like OSGI is important for Java community and how this framework fit in the big picture of application development using Java programming language.
The second chapter, Mastering Modularity, gradually introduces modularity and OSGI Module layer. The good point about the chapter is the way that it starts with explaining the modularity and the reason that modularity is important and its gradual move toward OSGI module layer, module description and modules dependencies. The authors introduces a sample program in this chapter which they further complete the software in each chapter. Chapter ends where its provided content make the readers ready to learn the OSGI service layer.
Welcome to the third chapter which is the longest chapter so far. This chapter is title Learning Lifecycle, and introduces the OSGI module life Lifecycle in a detailed manner. You can expect to see many sample code related to OSGI modules lifecyle and module management.This chapter introduces the OSGI module management API and use them in completing the "paint program".
Forth chapter, Studying Services, is what most of the readers are looking to understand in the beginning. The forth chapter starts in the same way that second chapter started, it gradually introduces the service concept and reasons for using services by providing very good illustrations. Later on author connect these concepts to OSGI service layer. Again you can see several sample code which shows how OSGI service layer works and how we can utilize OSGI framework API to manage the OSGI services lifecyle.
(Note: Opinions expressed in this article and its replies are the opinions of their respective authors and not those of DZone, Inc.)