A synergy between context-aware policies and AOP to achieve highly adaptable Web services

Modern service-based systems are frequently required to be highly adaptable in order to cope with rapid changes and evolution of business goals, requirements, as well as physical context in a dynamic business environment. Unfortunately, adaptive systems are still difficult to build due to their high complexity. In this paper, we propose a new approach for developing highly adaptable Web services based on a synergy between context-aware Web service policies and Aspect-Oriented Programming. This synergy is achieved through the elaboration of an innovative extension of the Web Service Policy Language (WSPL), which allows for context specification at both policy and rule levels. In addition, we provide a tool for the development of aspect-oriented policies, including an option to translate WSPL policies into aspect-oriented policies. These policies can be automatically woven into composite Web services (e.g., a BPEL process). The elaborated synergy between context, policies, and aspects allows service providers to increase the level of adaptability of Web services at different layers of applications.