Book Image

Apache Geronimo 2.1: Quick Reference

Book Image

Apache Geronimo 2.1: Quick Reference

Overview of this book

Apache Geronimo is a robust, scalable, secure, and high-performing application server. But like all application servers, this power comes with a steep learning curve. This book can help you save your time and get working with Geronimo in matter of a few hours. This book is a quick-reference guide to Apache Geronimo that mitigates the starting pains that most developers have when they migrate to a new Application Server. It will help you to extend and amplify your existing development skills, empowering you to build new types of applications regardless of the platform or browser. The book will introduce you to the exciting features of Apache Geronimo Application Server. You will see how easily you can develop and deploy Java EE 5 applications on Geronimo. It covers everything from downloading the server to customizing it using custom GBeans. By following the practical examples in this book, you will be able to develop applications quickly using Geronimo Eclipse Plugin. The book covers Geronimo internals in detail, which helps you write custom services on Geronimo. Also, it helps you to gain a deep understanding of Geronimo plugin architecture and teaches you to extend your server functionality via plugins. By the end of the book, you will develop proficiency in Geronimo and Java EE 5 application development.
Table of Contents (21 chapters)
Apache Geronimo 2.1
Credits
About the Authors
About the Reviewer
Preface

GBeans


A GBean is the basic unit in Apache Geronimo. It is a wrapper that is used to wrap or implement different services that are deployed in the kernel. GBeans are similar to MBeans from JMX. A GBean has attributes that store its state and references to other GBeans, and can also register dependencies on other GBeans. GBeans also have lifecycle callback methods and metadata. The Geronimo architects decided to invent the concept of GBeans instead of using MBeans in order to keep the Geronimo architecture independent from JMX. This ensured that they did not need to push in all of the functionality required for the IoC container (that forms Geronimo kernel) into the JMX implementation. Even though GBeans are built on top of MBeans, they can be moved to some other framework as well. A user who is writing a GBean has to follow certain conventions. A sample GBean is shown below:

import org.apache.geronimo.gbean.GBeanInfo;
import org.apache.geronimo.gbean.GBeanInfoBuilder;
import org.apache...