Software Tools for Separating Distribution Concerns

Simulation ... SimpleSimulation ... Front-end Back-end object gets modified by being sent as a parameter to the diffuse method in the Simulation class. Once the diffuse method returns having modified its Plate parameter, the front-end is signaled to repaint itself. The visual components can access the updated data of the Plate object and redraw. Note that the main computation logic of the thermal plate simulation is not distributed—the results are the only data transferred over the network for remote display and simulation control. Accomplishing the outlined distribution takes two steps: • Converting simulation classes into EJBs and deploying them in an application server. • Changing the client code to interact with an application server and EJBs instead of plain Java objects. Notice that making simulation classes remote while preserving the original execution semantics requires special handling for remote method parameters. The Plate object that participates in a complicated aliasing (i.e. multiple referencing) scenario now becomes