Migrating the Communication Protocol of Client-Server Applications

As part of a collaboration with Berger-Levrault, an international IT company, we are working on the migration of client-server applications. To escape legacy technologies and to evolve towards a "software as a service" model, the company decided to migrate the client side of its applications to Angular 14 and the server side to Spring Boot. In this paper, we focus on the migration of client-server communication from RMI and GWT-RPC to the REST architectural style. We identify issues associated with such a migration and propose a tool-based approach to address them. The migration involves (1) identifying existing services and exchanged data structures; (2) migrating the services; (3) migrating the data structures on the new client side; and (4) in some cases, reducing the amount of exchanged data to address performance issues. We experimented with our approach on four of the company's applications currently using RMI or GWT-RPC.