How might I go about checking whether Java is available when my external is loading inside a standalone?

I'm currently instantiating Java by attempting to create then delete an mxj object, in order to prevent the java-init-vs-defer issue I posted about earlier. If Java is not available, Max will post a "can't find mxj" error, and I'd like to avoid this if possible by testing if Java is available before trying to instantiate the object.