Research On Reengineering Of Legacy System Based On WCF

Computer software industry has been 50 years. A large number of applications have been developed. Due to historical reasons, many enterprise application softwares have problems, such as obsolete technology, poor structure, documentation loss and high maintenance costs; but they carry forward business-critical functions of enterprise applications , they can not be simply dropped. They become legacy systems.Legacy systems often have complex structures. User manuals and system design documents are out of date and inaccurate, which are unable to provide effective support for existing systems. As legacy systems hold the key business-critical functions of enterprise applications, we need to analyze them to a much higher level than code through reverse engineering, to understand function, design philosophy and method of operation, in order to maximize the reuse of it, and cut its development costs.Since the year 2000, .NET has provided a novel and efficient programming model for software development. Under this model, developers can focus more on their particular development scenario, rather than too much on the underlying operating system processing. Meanwhile, it provides rich interoperability technology, which enables developers to integrate .NET code and unmanaged code to reuse existing unmanaged code, instead of all original framework abandoned. WCF(Windows Communication Foundation) is latest software development kits for development and deployment of services in .NET framework. It provides developers with a successful solution to build cross-platform, secure, reliable enterprise-class Internet applications. Thus, by WCF, we can easily extend legacy systems into service-oriented environments.This paper aims to provide a practical guide to evolve legacy systems of enterprise-level in the Internet with a minimum cost and the fastest speed, by studying research methods of reverse engineering of legacy systems, C/S(Client/Server) and B/S(Browser/Server), as well as the WCF technology and .NET platform features. This article's goal is to publish legacy systems to Web services by WCF technology. At the same time, this article also describes the performance of WCF services.