Workshop: "Introduction to Qi4j a Composite Programming Framework in Java"
Track:
Tutorial
Time: Thursday 13:00 - 16:00
Location: Trifork
Abstract:
The inflexibility of the class based OO-paradigm manifested in the last decade in enterprise development. A new approach that gives object not classes the power to rule themselves became known as composite oriented programming.
This concept as well as most aspects of the Domain Driven Design approach were implemented in the Java based Qi4J framework by Rickard Öberg (JBoss, Xdoclet, Sitevision).Objects in COP are composed of fragments (Concerns, Sideeffects, Mixins) that define their possible roles. Properties, Associations, Validation are modeled explicitely. Objects are build using Builders or retrieved from Repositories using a fluent query abstraction. Working with objects in Qi4J is only possible in the bounds of long running unit of works that resemble business transactions. Moving from state based repositories to change trail bases implementations improved the flexibility even more. A lot of existing frameworks and libraries are usable within Qi4J to provide services at all levels.
The tutorial introduces the concepts that are the basis for composite oriented programming and the implementation done in Qi4J. Using examples from the official qi4j tutorials the different enhancements of the programming model are explained in detail.
Expect a mind blowing ride through the world of composite objects, fragments, roles and a sound DDD framework implementation.
As a core contributor of qi4j, Michael has got first hand deep insights and contributed to several of the design decisions of the framework.
see also: http://www.qi4j.org/
