Files.createDirectories(basePath);
            final Path realBase = basePath.toRealPath();
            Files.createDirectories(filePath.getParent());
            final Path realParent = filePath.getParent().toRealPath();
            if (!realParent.startsWith(realBase)) {
                logger.warn("Symlink traversal detected: url={}, realParent={}, realBase={}", url, realParent, realBase);