### Question:
FileHelper { public static boolean delete(File file) { if (file == null) return false; if (file.isFile()) return file.delete(); File[] files = file.listFiles(); if (files == null || files.length == 0) { return file.delete(); } for (File ff : files) { if (file.isDirectory()) { delete(ff); } else { if (ff.length() > 1024 * 1024 * 1024) { cleanFile(ff); } ff.delete(); } } return file.delete(); }  static void handlerWithLine(File file, String encoding, ObjectHandler<String> handler); static void processWithLine(File file, String encoding, Collection<E> result, ObjectProcess<String, E> process); static int lineCounts(File file); static List<String> readLines(File file); static List<String> readLines(File file, String encoding); static String readContents(File file); final static boolean createFiles(File file); final static boolean createFiles(File file, boolean isReNew); static boolean write(File file, String str); static boolean write(File file, String str, String encoding); static boolean addWrite(File file, String str); static boolean addWrite(File file, String str, String encoding); static boolean copy(File resource, File target); static boolean copyFile(File file, File targetFile); static boolean cleanFile(File file); static boolean delete(File file); static List<File> listFile(File path); static List<File> listFileSuffix(File dirPath, String postfixs); static List<File> listFileName(File dirPath, String fileName); static List<File> listFileNameIgnoreCase(File dirPath, String fileName); static List<File> listFileFilter(File path, ObjectFilter filter); static List<File> listFileNameReg(File dirPath, Pattern pattern); static List<File> listFileWithHandler(File path, ObjectProcess<File, File> handler); static boolean createFile(String path); static String suffix(File file); static String fileHash(File file, String HashTyle); static String simpleEncoding(File file); static boolean zipDeCompress(File file, String zipFile); static boolean zipUnCompress(File zipFile, String path);  }### Answer:
@Test public void testDelete() { File path = new File(TestUtil.path + "/temp"); FileHelper.delete(path); if (!path.exists()) { path.mkdir(); } }