Study On Component Composition Technology Based On XML Component Model

The software development method that based on component reuse is one of the available ways to resolve the crisis of software; Component-based software engineering provides a systematic framework for the construction, maintenance, and evolution of software applications and systems. Component-based software engineering has two fundamental elements, a component model that defines the standard for the interaction and the composition of components, and a component framework that supports the execution of the components that conform to the model. A number of component models have been defined and many have been widely adopted in practice. Examples of component models are CORBA, JavaBeans, Enterprise JavaBeans, COM, and .NET.These different component models have stimulated the rapid development of components by different developers, with the hope that eventually most components needed for application building will be available as off-the-shelf components. This dissertation is mainly focus on the study of component composition. How to compose applications has been impeded by many factors which have component model, component composition granularity, composition language, architecture and running environment. In fact,different component models lead to the problems of the component interoperability. Both component model and component composition are the inherent tight coupling, so the article imposes on composition component based on xml component model. Therefore, it provides XML DTD to define component composition model, and to describe component composition via XML document, and construct composition between methods and components via component composition operator set. Comparing to composition methods at present, the inherent tight coupling between XML DTD and XML document not only provide the same coupling between component model and composition, but also provide the supports of zero costs for development tools and ensure consistency for component, composition model, composition description. For implementing automation component composition the article puts forwards frame of component composition tool based on composition model, and set forth a particle scheme.This dissertation firstly study the theoretic basis,i.e.,software reuse, component technology and component composition method. Secondly we study component model based on XML, discuss XCM model elements in detail, and describe it via DTD. And then, it puts forwards a component composition model based on XML, conducts deeply research about component composition technology. Finally, we study automation component composition tools and testify component composition model based on XML through software development in practice.