Reengineering Legacy Systems Towards Web Environments

With the widespread use of the Web, distributed object technologies have been widely adopted to construct network-centric architectures, using XML, Web Services, CORBA, and DCOM. Organizations would like to take advantage of the Web in its various forms of Internet, Intranet and Extranets. This requires organizations to port and integrate their legacy assets to distributed Web-enabled environments, so that the functionality of existing legacy systems can be leveraged without having to rebuild these systems. In this chapter, we provide techniques to re-engineer standalone legacy systems into Web-enabled environments. Specifically, we aim for a framework that allows for the identification of reusable business logic entities in large legacy systems in the form of major legacy components, the migration of these procedural components to an object oriented design, the specification of interfaces of these identified components, the automatic generation of CORBA wrappers to enable remote access, and finally, the seamless interoperation with Web services via HTTP based on the SOAP messaging mechanism. Keywords: Software migration, software integration, software reengineering, legacy systems, multi-tie