Develop Aspect-Oriented Java Applications with Eclipse and AJDT

By Matt Chapman, Dr. Helen Hawkins
2005-05-16


Updated tools make AOP easier for beginners and veterans alike

AspectJ is an aspect-oriented extension of the Java™ language that enables a modular implementation of crosscutting concerns. This crosscutting behavior, which can be static or dynamic, presents an extra challenge to tools that support AspectJ. The AJDT project aims to provide Eclipse platform-based tools for AspectJ, consistent with the Eclipse Java Development Tools (JDT), with additional capabilities for visualizing and understanding the crosscutting nature of aspect-oriented applications. In this article, AJDT contributors and IBM aspect-oriented software development team members Matt Chapman and Helen Hawkins introduce you to AJDT. You'll learn how to install the tools; how to create, run, and debug AspectJ applications; and how to visualize and navigate the crosscutting structures inherent to aspect-oriented programming.

The AspectJ Development Tools for Eclipse (AJDT) is an open source Eclipse Technology Project that provides the tooling required to develop and run AspectJ applications. We believe good tools have a key role to play in realizing the full benefits of aspect-oriented programming, and particularly in helping newcomers understand the concepts involved.

After reading this article, we hope you will have a good feel for the support that AJDT provides for using AspectJ. We'll start by showing you how to get up and running with AJDT. Then we'll dive straight into things, creating an AspectJ application from scratch. You'll see how to create aspects and Java classes, and how to run the application. Our first example is very simple to keep the focus on the tools and introduce the different visual and navigational features that AJDT provides to help with your development. Even so, this simple application illustrates one real-world use of aspects.

We then move onto a slightly more complex example so that we can explore the tools in more detail, and show you how to work with existing projects. This example has several aspects that are integral to the application, as well as a debug aspect that we'll only want to include if we're actually debugging the application. We show how AJDT enables you to selectively apply and remove this debug aspect. After that, we visit the powerful Visualization perspective, to gain a higher-level understanding of how the many different aspects affect the rest of the application. Finally, we look at a couple of more advanced features of the tools, including those for debugging AspectJ applications and generating documentation.

Throughout this article, we are assuming some basic familiarity with AspectJ and aspect-oriented programming (AOP). For introductory material on AOP and programming in AspectJ, please see the Resources; alternatively, you can install AJDT and follow the Help links to AspectJ, where you will find the AspectJ documentation.

Tutorial Pages:
» Updated tools make AOP easier for beginners and veterans alike
» Installing AJDT
» First steps
» The Outline view and editor markers
» The Spacewar example
» Build configurations
» Aspect Visualization perspective
» Debugging
» Generating documentation
» Further options
» Conclusion
» Resources


First published by IBM DeveloperWorks

Related Tutorials: » All about JAXP, Part 1 » Make Database Queries Without the Database » Load List Values for Improved Efficiency » 2 Ways To Implement Session Tracking » A Simple Way to Read an XML File in Java » Java Validation With Dynamic Proxies