JSR 223 and Groovy 1.1 Beta 2

In Groovy version 1.1-beta-2 a new class groovy.lang.GroovySystem provides some nice features that I would like to use in my Google Summer of Code project. Namely, this is one way to implement a bundle activator for an eclipse plug-in. Not really an activator, actually, but sort of.

In a scripted bundle, the activator can be just a singleton class, and GroovySystem can be used to create a fancy singleton pattern in Groovy, like it is described at Groovy's homepage.

The problem I faced when I tried to initialize the scripting engine using javax.sript API, was that the engine implementation still thinks that groovy.lang.MetaClass is a class, but it is an interface in the latest version of Groovy.

So the stack trace of this exception was:

Exception in thread "main" 
java.lang.IncompatibleClassChangeError: 
at com.sun.script.groovy.GroovyScriptEngine
  .(GroovyScriptEngine.java:63)
at com.sun.script.groovy.GroovyScriptEngineFactory
  .getScriptEngine(GroovyScriptEngineFactory.java:87)
at javax.script.ScriptEngineManager
  .getEngineByName(ScriptEngineManager.java:225)

The quickest fix I could do, is to download the scripting engine sources from the website, and comment out the line in GroovyScriptEngine's static initializer. After the recompilation I didn't get the stack trace any more, but I think I have to investigate a bit more, what could be affected by this change.