This document provides an overview of OSGi application development and the Apache Aries framework. It defines enterprise applications as mission critical, large scale, and providing return on investment. It then covers key OSGi 4.2 specifications like web applications, JPA, JNDI, and JTA services. It introduces the OSGi Blueprint component model and Apache Aries packaging approach using Enterprise Bundle Archives. It concludes with a live demo of a stock trading application using these technologies.

1. © IBM Corp, 2010
Tim Ward | IBM
A crash course in OSGi application
development

2. © IBM Corp, 2010
A whistlestop tour
• What do we mean by enterprise?
• Enterprise 4.2 specs
– Web Applications
– JPA Service
– JNDI Service
– JTA Service
• The blueprint component model
• Apache Aries packaging
• Live Demo!

3. © IBM Corp, 2010
What do we mean by “Enterprise”?
• My definition (marketing):
– Mission critical
– Large Scale
– Return on investment
• My definition (technical)
– Reliable
– Accessible
– Legacy

4. © IBM Corp, 2010
Web Applications (OSGi 4.2)
• Support for Web Application Bundles
– OSGi bundles that are also WARs
– Servlet 2.5 support
• Web-ContextPath header
• Obeys Bundle-Classpath

5. © IBM Corp, 2010
JPA Service (OSGi 4.2)
• Support for Java SE unmanaged JPA
– Meta-Persistence header
• EntityManagerFactory services
• Apache Aries uses the same header
and service model for managed JPA
– Aries Blueprint extensions provide
JPA resource injection

6. © IBM Corp, 2010
JNDI Service (OSGi 4.2)
• Allows standard JNDI providers and
clients to work unchanged in OSGi
• The “osgi:” URL scheme allows JNDI
access to the service registry
– It even provides some dynamism

7. © IBM Corp, 2010
JTA Service (OSGi 4.2)
• Standardised access to
– UserTransaction
– TransactionSynchronizationRegistry
• Aries provides blueprint extensions
for declarative transactions
– Container managed
– Method level granularity

8. © IBM Corp, 2010
OSGi Blueprint (OSGi 4.2)
• A fine-grained dependency injection
container
– Manages service dynamics
– Supports complex internal wirings
• In Apache Aries blueprint is also the
heart of the programming model

9. © IBM Corp, 2010
Application Packaging
• In OSGi the unit of deployment is
the OSGi bundle
– No overarching “Application”
• In Aries we define an Enterprise
Bundle Archive (EBA)
– It contains metadata describing the
application

10. © IBM Corp, 2010
Application Packaging (2)
• An EBA lists the “core content”
– More bundles may be provisioned to
provide dependencies
• A bundle repository is used to
locate bundles for provisioning
– Bundles in the EBA can also be used
• Once provisioned an application has
fixed content

11. © IBM Corp, 2010
Demo
• A simple stock trading application
– It spans two databases, the “market”
and the “brokerage”
• It uses:
– A basic web front end
– JPA
– 2-phase container transactions
– Blueprint
– JNDI

12. © IBM Corp, 2010
Questions?
• Not much time now...
• Find me at the IBM stand outside if
you think of anything later
– More demos of Apache Aries in
Open Source and in WebSphere