Architecture-based software development has been shown as an effective approach for managing the implementation complexity of large-scale software systems. Architecture-based development is often achieved with the help of a middleware, which provides implementation-level counterparts for the architectural modeling constructs. Such a middleware automatically ensures that implemented system accurately embodies the properties encoded in its architectural models. However, existing middlewares do not provide sufficient support for architectural styles. This is due to the crosscutting structure of styles that impacts the behavior of every other architectural construct, and hence the corresponding middleware facilities. We present an aspect-oriented approach that alleviates this problem by weaving the stylistic concerns with the rest of the middleware. The approach decouples stylistic concerns from other middleware facilities, which in turn improves the middleware's understandability and flexibility, and enables rapid composition of hybrid styles. We evaluate the approach and describe our experiences by providing support for several well-known styles using two open-source middleware platforms.
