Design And Implementation Of Component Wrappers In The Heterogeneous Component Composition Model

The purpose of software components is to increase software reuse and to simplify the creation of new software through composition of existing components. Component composition is the core part of the component technology. Since the software components are independently developed, they cannot be entirely compatible with each other. Traditionally, component models are isolated and in general have no facilities to interconnect to components of different component model in a transparent way. This heterogeneity is a major limiting factor of today's software engineering processes. Up to date many research projects exist in the field of the heterogeneous component composition, but nearly none of them can resolve the problems completely.In this paper, we introduce a composition model which enables composition of heterogeneous components. We improve the design of the generic component model and component wrappers, meanwhile, we implement two kinds of component wrappers. Generic component model and component wrappers are important aspects of the composition model. They provide a uniform interface to other aspects of the composition model and specify how a client can access a component in a uniform way.What we do in this paper goes as:1. We Improve the generic component model: a component accessing layer is added to it to give a uniform instantiation mechanism and a unique component view, the component accessing layer supports a transparent accessing way.2. Besides property, method and eventset we give other two kinds of feature interfaces (ILifecycle and IPersist) for component wrappers. To each component model, there should be a corresponding component wrapper, and every wrapper should implement the interfaces provided in the generic component model. When the generic component model needs to support a new component model, it can be done by adding a corresponding component wrapper.2.We implement JavaBeans wrapper and COM+ wrapper. Different technologies are used to implement the two wrappers. JavaBeans Introspection and Java Reflection API are used in implementing JavaBeansWrapper and Java Native Interface are used in implementing COM+ Component Wrapper.