GlassFish Server has a modular architecture in which the features of GlassFish Server are provided by a consistent set of components that interact with each other. Each component provides a small set of functionally related features.
The modular architecture of GlassFish Server enables users to download and install only the components that are required for the applications that are being deployed. As a result, start-up times, memory consumption, and disk space requirements are all minimized.
The modular architecture of GlassFish Server enables you to extend the basic functionality of GlassFish Server by developing add-on components. An add-on component is an encapsulated definition of reusable code that has the following characteristics:
The component provides a set of Java classes.
The component offers services and public interfaces.
The component implements the public interfaces with a set of private classes.
The component depends on other components.
Add-on components that you develop interact with GlassFish Server in the same way as components that are supplied in GlassFish Server distributions.
You can create and offer new or updated add-on components at any time. GlassFish Server administrators can install add-on components and update or remove installed components after GlassFish Server is installed. For more information, see Chapter 10, Extending GlassFish Server, in Oracle GlassFish Server 3.0.1 Administration Guide.