A concrete solution for web services adaptability using policies and aspects

Abstract

Traditional middleware is usually developed on monolithic and nonevolving entities, resulting in a lack of flexibility and interoperability. Among current architectures, Service Oriented Architectures aim to easily develop more adaptable Information Systems. Most often, Web Service is the fitted technical solution which provides the required loose coupling to achieve such architectures. However there is still much to be done in order to obtain a genuinely flawless Web Service, and current market implementations still do not provide adaptable Web Service behavior depending on the service contract. Therefore, our approach considers Aspect Oriented Programming (AOP) as a new design solution for Web Services. Based on both WSDL and Policies contracts, this solution aims to allow better flexibility on both the client and server side. In this paper we expose our technical and concrete solution using Axis as the SOAP Engine, WSS4J as the WS-Security handler, and Javassist to weave some non-functional security aspects depending on the policies requirements.

Designing service-based applications in the presence of non-functional properties: A mapping study

“…Aspect-Oriented [13], [145], [130], [168], [176], [2], [129], [53], [177], [189], [203]. Software Product Line [154], [5], [86].…”

A Model-driven Approach to Service Policies.

“…However, there are variety of approaches [33,32] (including Ortiz et al's) using aspect-oriented programming techniques to handle crosscutting aspects like service management and adaptability. Our approach could complement those approaches and provide means to identify aspects and aid in the entire life-cycle of service policy development.…”

An Aspect Oriented Approach for Applying Features to Web Services

“…Some of the WSSpecifications specify policy assertions to describe their requirements (such as WS-ReliableMessaging). Based on this fact, [10] and [11] presents a policy driven approach for applying features to Web Services. The two major benefits of the policy driven approach is that it is flexible when applying a feature to a single Web Service and that it allows non-developers to apply features to Web Services.…”