gistfile1.java

String.metaClass.methodMissing { String name, args ->
    String camel = ''
    name.split('_').eachWithIndex { part, i ->
        if (i == 0) camel += part
        else camel += (part[0].toUpperCase() + part[1..-1])
    }
    
    def method = delegate.metaClass.methods.find { it.name == camel }
    if (method) {
        return method.invoke(delegate, args)
    } 
}

println "Who got their Ruby all over my Groovy?".to_upper_case()