Achieving Flexibility in Off-the-Shelf Middleware Services Integration

The development of component-based software engineering enables the construction of application servers by integrating reliable OTS middleware services. However it is di cult to achieve exibility in conventional hard coding way. In this paper, we propose a exible OTS middleware services integration framework to address this problem. In this framework, we de ne two kinds of modules: the middleware service contract module to represent the stable contract which speci es the abstract interaction logic between the application server and a kind of middleware services, and the middleware service implementation module to encapsulate the mutable implementation details of di erent OTS middleware services in a uni ed way. Additionally, we propose a module management mechanism to enable the application server to replace the OTS products at runtime via con guration. We implement the framework in a J2EE application server, and the evaluations show that our framework effectively reduces the cost and the time of maintaining and customizing the OTS middleware services-based application server.