Xml-based Distributed Software Architecture Research

Cuxrentiy, component-based soforare development is playin a more and mare important role insoftwar community. However, with the current component models and standards, the interfaceof component conveys limited semantics and the dependent relations among components andtheir interaction protocols are hidden within the implementation, which results in the problem ofcomposing mismatches, and also makes it difficult to reuse, validate and manage components.On the other hand, although software architecture is generatin tremendous interests andmany researches are made in this area, the practicability remains to be improved because it isdifficult to ensure the consistency between the architecture design and the systembolementation.In thes dissertation, we propose a message based architeed model named XDSA. Accordingto this model, cormponents could interact with each other through their connected ports bysending and receiving messages, and the connction of ports convey the semantics of componentcomposition. Ih this way, it is possible to outline the dependent relations and interactionprotocols among components during architectural design other than system implementation.Based upon XDSA model, we lay stress on the study of architecture description language, ADLmappings and supporting envirnment realization, interoperation with distributed objects, and theapplication of XDSA model on the Web platform.Based on the XDSA model, the XML-message based Architecture Description Language(XADL) adopts XML to specify the interaction messages among cormponents. XADL enhancesthe interface specification with the sequencing, behavior and quality constraints and supports thedescription of both static and dynamic connechons of components. As the results, the languageprevents systems from potential composing mismatches, and facilities the implementation oftools for system monitoring, performance analyzing, dynamic tuning and others.The XADL compiler has been developed to map the interface specifications intoimplementing skeletons. The supporting environment based on message queues ensures thereliable exchange of the intheraction messages of components. With the connections amongcomponents interpreted in the implementing skeletons, it is achieved the independence ofcomPonentS and their cormecting relations. ComPared with other ADLs and their tool sets,WL and itS comPiler ensure the consistency of architectUral design and systemimPlementation by supporting the hafOrmation betw6en them.By stUdying the OMG's interworking object model, we proPose and bolement theagent-based interoperation model betWeen XDSA comPoneni8 and distribut6d ObectS. TheXDSA agent comPonentS can be automatically gennded through interface Inappings, whichmakes it a prachcal way tO utilize the tremendous comPuting resources in the distributed objects.As the aPplication of XDSA model on the Web p1atform, we present the coInPonent viewmodel (WebView) which uses coInPonent view as a unifrm concePt to model Web enthes. Byusing the model in designing, it could etwe encaPsulation and reusability in the WebaPplication develOPment. The Web aPPlication forwork also has been irnPlementod byutilizing available Web technologies. As an bolementahon of the coInPonen view model, thefraInwor InaPs the comPOlled views intO the HTML fonna, and Provides the securitymechbosm, connection Inanagemellt and load balancing as well. Based on the forwork, thedevelopment productivity will be greatly promted.