gistfile1.txt

~/projects/jruby ➔ cat remote_rhino.rb 
require 'java'

$CLASSPATH << 'http://mirrors.ibiblio.org/pub/mirrors/maven2/rhino/js/1.7R2/js-1.7R2.jar'

ctx = org.mozilla.javascript.Context.enter
scope = ctx.init_standard_objects nil
result = ctx.evaluate_string scope, 'function f(x){return x+1} f(7)', 'x', 1, nil

puts result

~/projects/jruby ➔ jruby remote_rhino.rb 
8.0