This paper presents a Java framework based on separation of concerns and code generation concepts that facilitates development of concurrency and I/O in servers. In this approach, the application is modeled by a graph whose vertices correspond to units of treatment connected by channels. It allows to build all kind of servers: multithreaded, single-process event-driven, staged event driven architecture, etc. without modification of the functional part. This architecture also permits to extend very easily an application, adding vertices and edges to the graph. The aim of our development tool is to improve programmer productivity and portability, decreasing development time, and reducing bugs or deadlock problems.

In Java, method implementations are chosen at runtime by late-binding with respect to the runtime class of just the receiver argument. However, in order to simplify many programming designs, late-binding with respect to the dynamic type of all arguments is sometimes desirable. This behavior, usually provided by multimethods, is known as multipolymorphism. This work presents a new multimethod implementation based on the standard Java reflection mechanism. Provided as a package, it does not require any language extension or any virtual machine modification. The design issues of this reflective implementation are presented together with a new and simple multimethod dispatch algorithm that efficiently supports class loading at runtime. This implementation provides a practicable and fully portable multimethod solution.