Web APIs, characterized by their relative simplicity and their natural suitability for the Web, have become increasingly dominant in the world of services on the Web. Despite their popularity, Web APIs are so heterogeneous in terms of the underlying principles adopted and the means used for publishing them that discovering, understanding and notably invoking Web APIs is nowadays more an art tha...

New applications and software environments are increasingly distributed across a large or even unpredictable number of networked computing devices, require mobile and ad-hoc networking capabilities, and must integrate with more systems, all of which create greater demands on the middleware used to realize these systems. On the Java platform, RMI is a wellestablished paradigm, yet deficiencies b...

One of the main benefits of service-based systems is the loose coupling of components, which allows for flexibility in the selection of internal and external business partners. However, currently this flexibility is severely limited by the fact that components have to provide not only the same functionality, but do so via virtually the same interface. Invocation-level mediation may be used to o...

Invocation is the communication paradigm of objects. It is asymmetric by deenition: the invoker initiates the invocation whereas the invokee reacts to it. A proxy is a local representative of the invokee on the invoker's machine. Like the invocation, the proxy notion is asymmetric. However, when replicated objects are considered, there is a need for symmetric proxies: a regular proxy plus an in...

Abstract. Common object oriented systems have a fixed invocation semantic (synchronous procedure call). Some systems extend this concept with a fixed amount of additional semantics (RPC, best effort, asynchronous...). We claim that we have to go a step further and introduce invocation semantics as first class abstractions. We offer the possibility to write or compose completely new invocation s...

The Real-Time Specification for Java (RTSJ) provides a platform for the development of real-time applications. However, the RTSJ does not take the distribution requirements of real-time applications into consideration. As distribution in Java is often implemented using Java’s Remote Method Invocation (RMI), a real-time version of RMI between RTSJ implementations can provide a platform for writi...

This article focuses on transparency in the context of asynchronous method invocation. It describes two solutions available to provide full-transparency: where asynchronism is entirely masked to the developer. The main contribution of this paper is to clearly present the drawbacks of this approach: exception handling and developer consciousness are two problems inherent to full-transparency tha...