Research And Implementation Of Treasury Legacy System Base On WCF Technology

After years of development, a number of computer softwares have beendeveloped in the computer industry. The emergence of the component technologychanged the static model of original applications. Old components could bedynamically replaced by new components. With this new technology, applicationscan be developed over time, and the upgrade and maintenance of applications wouldbecome more flexible. Many applications have been developed in accordance to theCOM specification. The COM+technology combining COM, DCOM and MicrosoftTransaction Server (MTS) technologies together became the mainstream technologyto build the distributed enterprise applications at that time. After years of applicationmaintenance, all kinds of problems occurred in these enterprise systems. For example,the original design documents were outdated or missing; the outdated technologiescould not meet the needs of new business development; new staffs were unable tounderstand the complex business logic; the cost of system maintenance was too high.The maintenance of these old systems brought enterprises a larger burden. However,these systems were responsible for the core operational function in enterprises, theywere so-called legacy systems.Legacy systems played a very important role in enterprise’s daily operations.Companies have spent a lot of resources to maintain these systems, and a lot ofimportant data have been kept in these systems, which were valuable assets to theenterprises. Therefore, the treatment to legacy systems could not be simply abandoned. All relevant issues about the reuse of existing codes, the compatibilitywith existing data, the reduction of development costs, and the reduction ofre-engineering risk have to be considered by the enterprises.Microsoft’s.Net Framework provides COM Interop technology. With thistechnology,.NET code could access COM components which were implementedwith the unmanaged code. Developers could reuse existing COM components withoutmodifying the original components. WCF technology is a programming framework tobuild service-oriented applications. It integrates all related distributed developmenttechnologies on.Net platform.Based on WCF, Ajax, C#and other Microsoft-related technologies, the researchof this article is mainly about the re-engineering practice of legacy systems,combining with a case of re-engineering in a treasury management financial system.This study aims to provide a fast and low-cost solution for the re-engineering practiceof COM+component legacy system. It will be discussed how to reuse existing COMcomponents through the COM Interop technology; how to encapsulate the corebusiness components of legacy systems as WCF services; and how to use Asp.netAjax framework to invoke the asynchronous calls of WCF services. Meanwhile, thisarticle also describes a Scrum-based agile development practice and Nunit andWatir-based automated testing solution. It will provide relevant references for legacysystems those have similar problems.At present, the related achievements of this research have been successfullyapplied to a re-engineering project in a legacy system. Based on the proposedapproach, the legacy system has been migrated from an unmanaged platform to amanaged platform, and the architecture has been switched from C/S to B/S.Meanwhile, the introduction of automated testing process has significantly improvedthe quality of products, and reduced the maintenance costs.