Chapter 1. Modular development with Spring and OSGi
This chapter covers
- Java’s limitations regarding modularity
- How OSGi builds on Java for better modularity
- How OSGi and Spring are complementary solutions
Spring DM—or Spring Dynamic Modules for OSGi Service Platforms, as it’s more formally called—is about using the Spring programming model in OSGi applications. If you’re a Java programmer, you have probably heard of, or used, Spring—the dependency injection framework for Java. But what about OSGi? This dynamic module system for Java may be less familiar; but no matter, Spring DM is about OSGi for the masses, providing OSGi’s modularity features in a neat Spring-shaped package. You don’t need to get too involved in the nitty-gritty of OSGi to benefit from its features.
In this book, we’ll describe what Spring DM is, how to use it, and more importantly how to benefit from it. Because Spring DM is not only about using modular Java systems to get things to work—it’s about getting them to work well. We’ll also look at some of the implementation challenges involved in using Spring DM, challenges that boil down to OSGi’s strict classloading model. For instance, using object/relational mapping (ORM) tools or creating web applications can seem daunting in an OSGi environment, but never fear—we’re here to help!