Design And Realization Of Clearance Management System Based On Middleware

Middleware is a piece of software lying between the operating system and the application. Middleware, essentially, is a tool to make a distributed system developers life easier. It achieves this by hiding a number of the difficulties involved in building such systems. Since distributed systems may consist of components written in different languages and running on different operating systems, it is often helpful to have a single common development and runtime environment. This is one of the most significant advantages of middleware systems and will make the development of distributed systems easier. The research of middleware is now growing quickly,at same time most of large-scale software corporation and the Object Management Group(OMG) is developing many software products based middleware.For this reason, we design and build a middleware based Customs Clearance Management System-H2000. This system is co-developed by China Customs and Microsoft. The development proccess utilizes centralized development pattern, which guarantees high safty, high scalbility and high robustness. To develop the system, 3-tier architecture is adopted, ORACLE is taken as the database and Microsoft Visual Studio .Net is chosen as the development utilities for logic tier and view tier. This paper mainly research the middleware and introduce the applicationof middleware(etc. COM+) in the development of this system.This paper is organized as follows: Section 1 takes the concepts of middleware as a start point, introduces the advantages and characteristics of middleware and analyses the classification of various types of middleware as well as it's development trends. Section 2 discusses the mainstream middleware specifications, compares the three mainstream middleware platforms. Section 3 analyses and investigates the Microsoft DNA 2000 based distributed component model, which lays emphasize on the application of COM+ and N-tier model, that are embedded in Microsoft DNA 2000, in the development process. Section 4 analyses the role-based security authorization provided by COM+ and implements system security authentication using this mechanism combined with Windows KDC and SQL Server. Section 5 gives a detailed description of the design and implemetation of national and ministry degree research projects-the Customs Clearance Management System H2000.