Chapter 2. Geronimo Architecture

This chapter expands on what we discussed in the first chapter about the Apache Geronimo architecture. We will first see the concept of Inversion of Control (IoC) and dependency injection, which are two of the core concepts around which the current architecture is developed. We will then give a high-level overview of the internal architecture of Apache Geronimo and go through each component that makes up the architecture. Therefore, we will be covering GBeans, configurations, the kernel interface, repository, attribute store, dependencies, class loaders, deployment, plugins, and the concept of custom server assemblies. We will be covering these topics in detail so that you are able to understand the big picture. It will also help you if you want to contribute to Apache Geronimo or develop new services to run on Apache Geronimo. We will also list the different modules by their configuration IDs and map them to their functionality.

In this chapter, you will learn about:

• How Inversion of Control and dependency injection work

• GBeans —the building blocks of Geronimo

• Configuration— a collection of GBeans deployed together

• High-level architecture of Geronimo

• Class loader architecture

• Geronimo server directory structure

• Deployment architecture

• Plugins