Apparently reflection is not possible in GWT without jumping through hoops:http://stackoverflow.com/questions/4195233/can-you-use-java-reflection-api-in-gwt-clienthttps://groups.google.com/forum/?fromgroups=#
For the time being, carman23, it looks like the answer (as awful is it seems) is that in the Standard version, you have to send in an instance of the command and make sure that it doesn't do anything stateful (i.e. make sure to clear your variables each time execute is called).
In the MultiCore port (which this demo should get ported to) you could send the class reference.
The very oldest version of the framework did pass class references. Then it was completely replaced with the GWT version, and this demo didn't get updated.
This difference is untenable, and we'll have to address it, if I have to dive back into Java myself to do it. It has been many years, but it'd be a matter of tooling up again for it. Not a bad exercise.
The problem is just what to do, and I think it would be reasonable to move GWT to its own port. It can't be claimed to be Java without reflection. Java is Java and GWT is GWT. Therefore it would become the GWT standard port and we'd backport the Java MultiCore to Standard and just strip it of the multicore aspect.
That is a tangle in terms of people who may be using the port, but moving it to a branch is not something that works well either for the long term.