Com +-based Graduate School Of Management. Net Collaborative Office Systems

With the rapid development of information technology and the evolution and popularity of Internet since 1990, a new application program which is highly distributed on Internet is urgently desired. The traditional architecture of application program can't meet the need for the new application program. How to organize the computers on network working harmoniously and coming into a distributed parallel environment, and to develop a large complicated distributed business application program, now has become the hot point now.By analyzing the advantages and disadvantages of popular distributed object technology, this paper introduces a new architecture to construct Web-based distributed application program, which is called COM+ based distributed Web application program. Basing on the Windows DNA's three tied application program architecture and using the services provided by COM-f, this architecture provides a new flexible and workable solution to develop Web based application program under the distributed computing environment, logically this solution splits a enterprise application program into three abstract ties: express tie, business logic tie and data service tie. Using SOAP, this paper also presents a method to call components of programs on other networks, other systems and other object models. The system uses COM+ to distribute application program on the same platform on intranet, while it takes advantage of SOAP to call components on Internet or different platform on intranet. This paper also discusses some topics associated with the distributed Web based application system model, including: system architecture model, distributing illustration, working principle and technology characteristic.This paper also introduces an example, the Postgraduates Management Collaboration Handle Official Business System. Net (PMCHOBS.Net), which is an Internet-based distributed application, to interpret the principle of COM+ based distributed Web application system, and discusses the advantages and disadvantages between the COM+ based system and the traditional Client/Server system. The actual achievement methods for COM+ based distributed Web application is given here, including present layer, business logical layer and data service layer. Combining the requirement for off-line data input, it also presents the way to asynchronous data transporting and component accessing.A summarization is given at the end of the paper, which gives the characteristics of the COM+ based distributed Web application model, and it's prospect. The COM+based distributed Web application is a new way to develop large distributed enterprise application under the wide area network environment, especially applying the COM+ services and SOAP technology to achieve asynchronous data transporting and component accessing, and to assemble the present application systems across networks, systems and object architectures. We believe that the COM+ based distributed Web application system model can take a great part in developing large distributed enterprise application system.