What is OSGi? Simply put, OSGi is a standardized technology that allowsdevelopers to create the highly modular Java applications that are required forenterprise development. OSGi lets you install, start, stop, update, or uninstallcomponents without taking down your entire system. The interest in OSGi basedapplications has exploded since major vendors like Sun, Spring, Oracle,BEA, and IBM have gotten behind the standard.
OSGi in Action is a comprehensive guide to OSGi with two primary goals.First, it provides a clear introduction to OSGi concepts with examples that arerelevant both for architects and developers. Then, it explores numerous practicalscenarios and techniques, answering questions How much of OSGi doyou actually need? How do you embed OSGi inside other containers? What arethe best practices for moving legacy systems to OSGi?
Purchase of the print book comes with an offer of a free PDF, ePub, and Kindle eBook from Manning. Also available is all code from the book.
This is probably the (or one of the) most holistic books about OSGi. It's obvious the authors have put a lot of effort into it. The book has a nice structure, being segmented into 3 main parts. The first gives an introductory overview to the basic concepts of OSGi (modules, lifecycle & services), the second part covers the practical elements (testing, debugging etc.) and the last part contains advanced topics (component model & frameworks, security, web etc.). The authors start from Java fundamentals, which makes it an easy to read book for people without extensive experience around Java (e.g. about topics, like class loading). They draw from their experience working on OSGi to also provide a lot of context around historical decisions (e.g. to maintain backwards compatibility) that can help the reader understand why something works the way it works (sometimes counterintuitively) and what alternatives exist. I liked the fact that the book is example-driven and not just talking in the abstract; the reader sees how the theoretical concepts can be used in practice to build a toy paint application in a modular fashion using OSGi. I sometimes felt that the book was following a depth-first approach right off the bat, which might overwhelm some readers. For example, the book starts explaining in detail the resolution rules at an early point, where the topics are introduced. However, this was not done extensively and it was easy (at least for me) to quickly jump these sections, if needed. As a disclaimer, I only read the first part (out of 3) as I was interested in a good overview of the main building blocks of OSGi for a new project. The structure of the book helps in that, because I can come back later on and read specific sections if I want to learn about a specific aspect/feature of OSGi.
very good, deep and well written guide into OSGi. After reading a few most important chapters I was able to decide if OSGi is worth using in my case, then successfully use it.
Actually I only read part of the eBook early access version of the book. Although SpringSource is seriously pushing their new OSGi framework and SpringDM server, I guess the whole thing still has to mature and the community has to grow... I'm not convinced SpringDM can offer that much of a benefit to my projects. Although the presentation in the book is clear, I found it quite dull most of the time, and had trouble keeping my interest... Still probably a good getting-started introduction for the framework.