for (final File f : folder.getFile().listFiles()) {
final String id = this.idservice.getId(f);
if (f.isFile()) {
foundFileIds.add(id);
if (! knownFileIds.contains(id)) {
ScanFile addedFile = folder.addFile(id, f);
if (addedFile != null) {
list.add(addedFile);
}
}
} else {