Part 1. Spring DM basics

Welcome to Spring Dynamic Modules in Action. Spring Dynamic Modules—a synthesis of Spring and OSGi-is the technology that can help you write better, more beautiful, programs. In these first three chapters, we are going to discuss the basics of all three technologies—Spring, OSGi, and Spring DM—and by the end you should have a good idea of why these technologies can help address the thorny problems associated with unmodular applications.

In chapter 1, we cover the concepts of Java modularity in general—since Spring DM and OSGi are primarily technologies that enabled modularity—the specifics of the Spring Framework, and the features of OSGi. We then move on to show you where Spring DM fits in, and how its approach and its features simplify the development of standard Java applications in an OSGi environment. The concepts covered are reinforced in later chapters, so if you want to get the flavor of the whole book, chapter 1 is a good place to start.

Chapter 2 is an OSGi primer, focusing on how you can take advantage of OSGi technology within your Java applications. It introduces the main building blocks of OSGi: bundles, wiring, and services.

At last, in chapter 3, we are ready to get down to the main business of Spring DM. There is a lot to learn and we introduce all of the main features and concepts here—dependency injection, extenders, writing bundles container provisioning, fragment configuration, and application development using Maven.