Using Apache Sling's Scala 2.8 Script Engine - apache

Question

I've been trying to use Apache Sling's Scala 2.8 Script Engine recently updated last month. I came from using Scala 2.7 along with Sling's Scala 2.7 Script Engine and that worked great. I run into a problem when I try to use the new implementation. When calling ScalaScriptEngine's eval function I always receive an "Error executing script" due to a NullPointerException. Has anyone else worked with the new build of the script engine and run into this as well?
Thanks!
Steven

Answer 1

There is a bug which prevent the Scala scripting engine from being used standalone. See https://issues.apache.org/jira/browse/SLING-1877 for details and a patch.
Also note, that with the patch applied you still need to set the class path when using the scripting engine. This is a change from 2.7.7 where the default java class path (i.e. java.class.path) was used automatically. In 2.8 you have to set this explicitly thorough the '-usejavacp' argument.
Here is some sample code demonstrating the standalone usage of the Scala scripting engine:
def testScalaScriptEngine() {
val scriptEngineFactory = new ScalaScriptEngineFactory
val settings = new ScalaSettings()
settings.parse("-usejavacp")
scriptEngineFactory.getSettingsProvider.setScalaSettings(settings)
val scriptEngine = scriptEngineFactory.getScriptEngine
val script = """
package script {
class Demo(args: DemoArgs) {
println("Hello")
}
}
"""
scriptEngine.getContext.setAttribute("scala.script.class", "script.Demo", ScriptContext.ENGINE_SCOPE)
scriptEngine.eval(script)
}