The Research On Core Container And Dynamic Management Of Services For Aspectual Middleware

Under the background of On-Demand Computing problem, this paper firstly introduces the architecture and Aspect-Oriented Programming (AOP) implementation of three typical middleware platforms, analyzes the pros and cons of them on architecture extensibility, dependency relationship management and AOP supporting granularity, and concludes their common disadvantages.Then, for above disadvantages, this paper puts forward a new model on aspectual middleware--Dual Core Aspectual Middleware model (DCAM), which consists of core layer, service layer, application layer and aspect layer. The model applies AOP functional support to the core layer to support aspectual components working on service layer as well as application layer. It also uses the declaration-based service lifecycle management mechanism to reduce the coupled degrees between services and platform and improve the extensibility and compatibility of services. Moreover, the wrapper-based container structure provides the extensible foundation of dependency relationship management for components based on IoC containers. All above mechanisms make the model more effective on extensibility, dependency relationship management and fine-granular AOP support, as well as on On-Demand Computing because of the component mobile support.Next, the design and implementation of the model is stated. The core entities of each layer have built up the running basis of the prototype system, and four services are supplemented to provide platform-negotiation, component mobility and client-side invocation to fulfill the DCAM design ideas.Finally, this paper displays the running sample's screenshots of the prototype system, and illustrates its pros and cons. Furthermore, it analyses the price paid for the several features in the framework designs through experiments, which are carried out from the perspectives of system-bootstrap time and component-processing time.