### Question:
ImageUtil { public static List<String> generateThumbnail2Directory(String path, String... files) throws IOException { return generateThumbnail2Directory(DEFAULT_SCALE, path, files); }  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 testGenerateThumbnail2Directory() throws IOException { String path = "D:\\workspace\\idea\\individual\\springboot-learn\\springboot-thumbnail\\image"; String[] files = new String[]{ "image/1.jpg", "image/2.jpg" }; List<String> list = ImageUtil.generateThumbnail2Directory(path, files); System.out.println(list); }