Introduction to Xholon

Introduction to Xholon

This page introduces the Xholon runtime framework.

The Xholon runtime framework has been developed sufficiently to be able to run the sample applications included with the software. The code has not yet been optimized for performance.

Technical Details on the Xholon runtime framework

The Xholon software is written entirely in Java, and has been tested with several releases of Sun's Java J2SE 1.4.2. It was developed using Eclipse, but does not in any way require Eclipse. It was developed under Windows XP, and is regularly tested on charmeleon running Debian Linux. It should run on any computer that supports Java applications.

In terms of the Model View Controller paradigm, a Xholon application is just a model. A simple default tree viewer has been implemented using the Java swing JTree component. Models can be executed without this Xholon GUI, but it does function in a limited way as a controller. Use the GUI to start, pause, un-pause, step and stop Xholon applications, to inject messages into an executing Xholon model, and to view various things happening at run-time. Other viewers could be used instead.

The Xholon runtime framework reads in a number of XML files on start-up. It uses the XML pull parser XPP3 to read the XML. These XML files can optionally be automatically derived from a UML2 model saved as an XMI file. This has been done using MagicDraw 10.5, Poseidon 3.2, XMI 2, XMI 1.2, xalan-j 2.7, and custom xsl files to specify the xmi to Xholon transformations.

UML to Xholon transformation pipeline

A Xholon model makes extensive use of XPath syntax to navigate the containment hierarchy tree, both during configuration and during normal run-time processing.