Running javascript inside a sandbox in a jvm

I'm putting a couple of pieces together here that weren't in one place.  When introducing Rhino javascript engine into our code, we wanted to lock down its access.  Java 6 hides the internal Rhino context well enough that I couldn't figure out how to get at it.  So to restrict access to a given set of classes when running untrusted Javascript inside the JVM you need to start your own Rhino context up, then hook in the filter.

The useRhinoDirectly() method gives a Rhino context in which we can set up a class filter:
http://stackoverflow.com/questions/4639892/whats-the-difference-between-java-6s-built-in-version-of-rhino-and-the-rhino-pa

Building the class filter is easier standing on someone else's shoulders.  This example blocks access to static methods:
http://riven8192.blogspot.com/2010/07/java-rhino-fine-grained-classshutter.html
(Not sure which Text class this was using, but String.split() seemed to do the job.)