### Question:
ImageUtil { public static void generateDirectoryThumbnail(String pathname) throws IOException { generateDirectoryThumbnail(pathname, DEFAULT_SCALE); }  static List<String> generateThumbnail2Directory(String path, String... files); static List<String> generateThumbnail2Directory(double scale, String pathname, String... files); static void generateDirectoryThumbnail(String pathname); static void generateDirectoryThumbnail(String pathname, double scale); static String appendSuffix(String fileName, String suffix); static boolean isImage(String extension); static String getFileExtention(String fileName);  }### Answer:
@Test public void testGenerateDirectoryThumbnail() throws IOException { String path = "D:\\workspace\\idea\\individual\\springboot-learn\\springboot-thumbnail\\image"; ImageUtil.generateDirectoryThumbnail(path); }