Distributed Application Based On COM Component

With the development and popularity of Internet, Browse/Server application system based on Web is turning up and developing. Although current Web technology is of some unique merits , it still can't support large-scale enterprise computing. Developing distributed Web application which combines ASP technology and COM can be suitable for requirement's change with part updating, and it integrates with the other application. It makes client call by application object through the Web Server and improve the performance of the system. The integration of Web technology and component object technology is the developing trend of Web system.Component object model is a software criterion based on binary system standard and is independent on the program language. It shows how to load object and define component and create component. The middleware logical layer based on COM can establish a steady, easy maintained and easy upgraded application system by using these specialties.The paper focuses on research and application on Web system based on distributed object technology. At first, a summary of development of distributed structure is made, and the advantage and disadvantage of three-layer based on Web technology is made up. Then the distributed object technology is expounded by introducing three technologies of distributed object:COM/DCOM technology, CORBA technology and Java/RMI technology. Through analyzing and comparing three technologies, the advantage of COM component is explained , and the component of Windows DNA is simply introduced. The three-tier frames based on COM component is explained in the paper.Combining with a special application: Web-based examination system, the development course of Web system based on component technology is introduced in the paper. System background is analyzed at first, then requirement analysis and the choice of realization technology is discussed. Through summing up Web databasetechnology, the technology route-Web application combined ASP and COM isput forward. Then system detail design is gone into, including summary, component design, object design, database design and data access design. In the end, realization of EXAM component and dispose of system is particular illustrated in the paper. Whole course based on COM component is expounded in the paper.