Resolving filename conflict

In case i forget

/*
*Returns a existing file if the filename given has already been used in a folder/root
**/
public FileResource getConflictedFile(String fileName, String licenseKey, Long parentDirectoryId){
 return FileResource.withCriteria(uniqueResult:true){
  ilike("name","%"+fileName+"%")
  eq("licenseKey",licenseKey)
  if(parentDirectoryId){
   parentDirectory{
    eq("id",parentDirectoryId)
   }
  }
  else{
   isNull("parentDirectory")
  }
  fetchMode("parentDirectory",FM.EAGER)
 }
}

public String createUniqueFileNameInFolder(String fileName, String licenseKey, Long parentDirectoryId){
 def file = getConflictedFile(fileName, licenseKey, parentDirectoryId)
 if( file ){
  def fName = file.name
  int dotPos = fName.lastIndexOf(".")
  def name = fName.substring(0,dotPos);
  def fileExt = fName.substring(dotPos+1);

  //check if there is a _numeric at the end of the file name
  if( name.lastIndexOf("_")==-1 ){
   fName = name+"_1."+fileExt;
  }
  else{
   int usPos = name.lastIndexOf("_");
   def copyNumber = name.substring( usPos+1 )
   if( copyNumber.isLong() ){
    copyNumber = copyNumber.toLong()+1
    name = name.substring(0,usPos)
    fName = name+"_"+copyNumber+"."+fileExt;
   }
   else{
    fName = name+"_1."+fileExt;
   }
  }
  //if yes then extract, increment, append and rerun again until no conflicts
  return createUniqueFileNameInFolder(fName,licenseKey,parentDirectoryId)
 }
 else{
  return fileName;
 }
}