Good to see a functional-like implementation with Java. There are good functional constructs for Java implemented in http://functionaljava.org and also Apache Commons Collections hosts some Closure implementations and other functional idioms.

Another new library trying to implement functional idioms over collections is lambdaj: http://code.google.com/p/lambdaj/

Hopefully all these functional idioms will be somehow supported by the language, either through closures and libraries, otherwise we have Scala, Groovy, Clojure to the rescue.

Karel