### Question:
SimpleExample { public void listFilesChange() throws IOException { System.out.println("==========对文件夹所有图片进行操作============"); Thumbnails.of(new File(imgDir).listFiles()) .scale(1.0f) .outputFormat("png") .toFiles(new File(saveDir),Rename.PREFIX_DOT_THUMBNAIL); System.out.println("\r\n"); } SimpleExample(String saveDir); void reSize(); void scale(); void forceReSize(); void rotate(); void watermark(); void sourceRegion(); void outputFormat(); void listFilesChange(); static void printlnImageInfo(String imgFile);  }### Answer:
@Test public void listFilesChange() throws IOException { simpleExample.listFilesChange(); }