Study Of Construction Model For Legacy System Based On Web Services

Legacy software reuse plays a more and more important role in software production today. At the same time, how to take the advantages of legacy software systems effectively has become a hot discussion topic in current software engineering.Service-oriented architecture as one of the next generation software architecture has become the best choice for component-based software reuse. Web services as one of the important ways to realizing service-oriented architecture, by its interoperability, universality, simplicyty and good industry support, more and more organizations and system developers welcome this new technique. Reconstructing legacy system by Web Service technology is an attempt of applying emerging technology to practice, and provides a new thinking to deal with the legacy systems.This thesis considers how to dispose the legacy systems in depth, studies some current models and methods in treating with legacy systems, sums up the problems when deal with legacy systems, and points out the theoretical significance and practical significance of this research. This thesis proposes a reconstruction model based on Web Services. In response to the reconstruction model, combining traditional software engineering method and object-oriented technology, we put forward the process of reconstrctin legacy systems base on the model by system analysis, reconstruction modeling, Web Services component packaging and the new system inegration. This thesis illustrates the packaging process from data layer, transaction layer and application layer in details, then analyses some interrelated quality elements and puts forward the corresponding solution.In order to further the theory and methods proposed above, a teacher performance management application system is introduced at the end of this thesis. This system reuses the old business logic information, and takes advantages of legacy score system, improves the software development quality and reliability. At the same time, this system reconstruction method reduces system development costs in a certain extent, and good results have been received.