Browsing by Author "Kangasaho, Mikko"

Legacy systems are software systems that hold great value to organizations, but which are difficult to maintain. Legacy systems can be wrapped with a REST wrapper in order to reuse their data and business logic. The motivation for the wrapping is to decouple new development from the legacy system so that the new development is not directly dependent on the legacy system's internals. The hypothesis I've seen in the software industry is that REST wrapping makes new development faster because the complexity of the legacy system does not slow new development down. Eventually the goal is that the legacy system can be incrementally replaced without changes to the clients that use its services via the REST API. This thesis examines REST wrapping by reviewing existing literature. REST wrapping as a concept is placed in the theoretical context of modernization techniques applied to systems in their post-delivery life cycle. In addition to conceptual clarification, two case studies found from the literature and the author's experiences in the software industry are examined to determine whether they support the theoretical models of REST wrapping as a modernization technique. The literature provided support for the notion that REST wrapping provides a low-cost way to reuse legacy systems functionality and data. It was also found to reduce the complexity of developing new functionality on top of a legacy system. The biggest shortcoming of REST wrapping is that it leaves the legacy system mostly unchanged. Like wrapping in general also REST wrapping is a short-term solution to legacy system's problems. It can be seen as a way to buy time to develop a long-term solution for the legacy system. ACM Computing Classification System (CCS): Software and its engineering → Software evolution Applied computing → Service-oriented architectures Information systems → RESTful web services