OSGi in Depth

Foreword

After many years in ClassPath-land, the Java industry at large is finally starting to see the need for modularity in software development and deployment. There are many reasons for this. Maybe you just want to get out of the Jar Hell, where you’re not quite sure anymore where a particular class comes from in your deployment. Other use cases for modularity center around providing isolation in a multi-tenancy context.

But there are more reasons. A modular approach makes developing software more scalable as modules tend to be highly focused with a clear demarcation of responsibility. A module’s internals are inaccessible to the outside, which means that a modular approach tends to lead to well-defined APIs that better allow for concurrent ...