Modularizing communication middleware concerns using aspects

software engineers often rely on communication middleware platforms to design and implement distributed systems. however, middleware functionality is usually invasive, pervasive and tangled with business-specific concerns. in this paper, we describe an aspect-oriented distributed programming system that encapsulates middleware services provided by java rmi and java idl. the proposed system, called daj, handles the basic service provided by such object-oriented middleware platforms, i.e., synchronous remote calls using call by-serialization and call by-remote-reference semantics. the paper documents our experience in using daj to modularize middleware concerns from three legacy distributed systems.