Making Service-Oriented Java Applications Interoperable without Compromising Transparency

Abstract

Object-oriented programming languages lack high-level support for platform-independent service interactions. In Java, for instance, the burden of guaranteeing sustainable interoperability is put entirely on the programmer. Java Remote Method Invocation requires its invocation targets to be remote Java objects, so Web Services and other targets can never be invoked without verbose interactions with specialized library classes. This lack of transparency forces programmers to consider heterogeneity problems over and over again, even though interoperability is ideally a middleware responsibility. Also, the mix of business logic and technical concerns obfuscates the source code, thus decreasing maintainability and code comprehension. In this paper, we show that interoperability in Java applications can be achieved without compromising transparency. We describe a Java extension and focus on how this language enables a precompiler to transparently inject the boilerplate code that realizes interoperable service interactions. Deferring interoperability provisioning to such a precompiler allows programmers to focus on the implementation of the business logic without being distracted by heterogeneity issues occurring in the service architecture in which their application will eventually be deployed.