in commons-rdf-simple/src/main/java/org/apache/commons/rdf/simple/experimental/AbstractRDFParser.java [96:107]
private static Optional<String> fileExtension(final Path path) {
final Path fileName = path.getFileName();
if (fileName == null) {
return Optional.empty();
}
final String fileNameStr = fileName.toString();
final int last = fileNameStr.lastIndexOf(".");
if (last > -1) {
return Optional.of(fileNameStr.substring(last));
}
return Optional.empty();
}