We contribute to addressing context of Java and the type-based publish/subscribe (TPS) abstraction, an object-oriented variant of the publish/subscribe paradigm. We present an experience that compares implementations of TPS in (1) a variant of Java we designed to inherently support TPS, (2) standard Java, and (3) Java augmented with genericity. We derive from our implementation experience general observations on what features a programming language should support in order to enable a satisfactory library implementation of TPS, and finally, also alternative abstractions. In particular, we (re-) insist here on the importance of providing genericity and reflective features in the language, and point out the very fact that current efforts towards providing such features are still insufficient.

Distributed application development is overly tedious, as the dynamic composition of distributed components is hard to combine with static safety with respect to types (type safety) and data (encapsulation). Achieving such safety usually goes through specific compilation to generate the glue between components, or making use of a single programming language for all individual components with a hardwired abstraction for the distributed interaction. In this paper, we investigate general-purpose programming language features for supporting third-party implementations of programming abstractions for distributed interaction among components. We report from our experiences in developing a stock market application based on type-based publish/subscribe (TPS) implemented (1) as a library in standard Java as well as with (2) a homegrown extension of the Java language augmented with specific primitives for TPS, motivated by the lacks of former implementation. We then revisit the library approach, investigating the impact of genericity, reflective features, and the type system, on the implementation of a satisfactory TPS library. We then discuss the impact of these features also on other distributed programming abstractions, and hence on the engineering of distributed applications in general, pointing out lacks of mainstream programming environments such as Java as well as .NET.

This paper presents linguistic primitives for publish/subscribe programming using events and objects. We integrate our primitives into a strongly typed object-oriented language through four mechnisms: (1) serialization, (2) multiple subtyping, (3)closures, and (4) deferred code evaluation. We illustrate our primitives through Java, showing how we have overcome its respective lacks. A precompiler transforms statements based on our publish/subscribe primitives into calls to specifically generated typed adapters, which resemble the typed stubs and skeletons by the rmic precompiler for remote method invocations in Java

Modeling is important in object-oriented software development. Although a number of Computer Aided Software Engineering (CASE) tools are available, and even though some are technically advanced, few developers use them. This paper describes our attempt to examine the requirements needed to provide tool support for the development process, and describes and evaluates a tool, Knight, which has been developed based on these requirements. The tool is based on a direct, whiteboard-like interaction achieved using gesture input on a large electronic whiteboard. So far the evaluations have been successful and the tool shows the potential of greatly enhancing current support for object-oriented modeling.