The Crosscutting Mechanism In Concurrent Aspect Of B/S Based Web Application And Its Implementation

Aspect-Oriented Programming (AOP) is based on the Object-Oriented Programming (OOP) system. It is developed to reduce the inefficiency of OOP in fulfilling such non-nuclear requirement as those concerning several units of modularity at the same time. To fulfill such a multi-facet task, AOP detracts the crosscutting concerns scattering or interwoven around the core concerns of OOP and modularizes them through "Aspect". So AOP is considered as the counterpart and complement of OOP.Currently, almost all approaches to AOP provide means for the description of Sequential Event-based AOP, but seldom have previous mechanisms provided formally-defined concurrent approach to Concurrent Event-based AOP, with the result that coordination issues between aspects and base programs as well as between aspects cannot precisely be investigated.In this paper the author puts forward a new design model—M~+VC_CA model which includes "Concurrent Aspects" in the present MVC model. Meanwhile, by analyzing the finite sequential processes of concurrent events in web applications adopting B/S model, we provide another way to realize the concurrent aspects of M~+VC_CA model——Layered Concurrency Aspects Implementation Method(LCAIM), which is eventually successfully adopted in ESS system in this study. In conclusion, AOP designs in this paper help deal with problems in designing and implementing methods of concurrent aspects of concurrent events.