JAsCo&WSML: AOP for Component-Based Software Engineering applied to a Web Services Management Layer

Wim Vanderperren, Vrije Universiteit Brussel
Davy Suvée, Vrije Universiteit Brussel
Bart Verheecke, Vrije Universiteit Brussel
María Agustina Cibrán, Vrije Universiteit Brussel

Wednesday, March 24, 14:00
Friday, March 26, 09:30

JAsCo is an aspect-oriented programming language, which is tailored for Component-Based Software Engineering. JAsCo introduces independent and reusable aspect beans that can be instantiated onto a concrete component context using connectors. In addition, connectors allow the explicit description of precedence and combination strategies that are able to control the collaboration among several cooperating aspects. The JAsCo technology introduces a new component model based on built-in traps that allow aspect interference. As such, aspects can be added and removed dynamically without requiring invasive changes to the target components. In order to optimize dynamic AOP, JAsCo also supports the Java HotSwap technology in such a way that only those joinpoints where aspects are applied upon are trapped. When new aspects are added or removed, all corresponding joinpoints are hotswapped for a trapped version or unswapped for the original version.

Attendees will see a demonstration of the Web Service Management Layer (WSML), illustrated as an elaborated case study of the JAsCo approach. The WSML aims at decoupling client applications from concrete web services. In addition, the WSML enables advanced service selection based on both functional and non-functional properties of web services. By employing AOP, several crosscutting concerns that would normally be tangled in the client application can be easily modularized. The main advantages of the JAsCo language in the context of the WSML are the explicit and elaborate combinations that can be specified between interacting aspects. In addition, the dynamic property of JAsCo is exploited to achieve run-time service integration and selection.