StrSubstitutor substitutor = new StrSubstitutor(new SolrCoreStrLookup(
indexReference, core, bundleContext));
substitutor.setEnableSubstitutionInVariables(true);
String folderStr = substitutor.replace(fstFolderConfig);
if(folderStr.indexOf("${") > 0){
folderStr = substitutor.replace(folderStr);
}
//convert separators to the current OS
folderStr = FilenameUtils.separatorsToSystem(folderStr);
File fstDir = new File(folderStr);
if(!fstDir.isDirectory()){ //create the FST directory