java io文件操作删除文件或文件夹的7种方法

//false只能告诉你失败了 ，但是没有给出任何失败的原因
@Test
void testDeleteFileDir1()  {
   File file = new File("D:\\data\\test");
   boolean deleted = file.delete();
   System.out.println(deleted);
}
//void ,删除失败没有任何提示，应避免使用这个方法，就是个坑
@Test
void testDeleteFileDir2()  {
   File file = new File("D:\\data\\test1");
   file.deleteOnExit();
}
//如果文件不存在，抛出NoSuchFileException
//如果文件夹里面包含文件，抛出DirectoryNotEmptyException
@Test
void testDeleteFileDir3() throws IOException {
   Path path = Paths.get("D:\\data\\test1");
   Files.delete(path);   //返回值void
}
//如果文件不存在，返回false，表示删除失败(文件不存在)
//如果文件夹里面包含文件，抛出DirectoryNotEmptyException
@Test
void testDeleteFileDir4() throws IOException {
   Path path = Paths.get("D:\\data\\test1");
   boolean result = Files.deleteIfExists(path);
   System.out.println(result);
}

private  void createMoreFiles() throws IOException {
   Files.createDirectories(Paths.get("D:\\data\\test1\\test2\\test3\\test4\\test5\\"));
   Files.write(Paths.get("D:\\data\\test1\\test2\\test2.log"), "hello".getBytes());
   Files.write(Paths.get("D:\\data\\test1\\test2\\test3\\test3.log"), "hello".getBytes());
}

@Test
void testDeleteFileDir5() throws IOException {
   createMoreFiles();
   Path path = Paths.get("D:\\data\\test1\\test2");
   Files.walkFileTree(path,
      new SimpleFileVisitor<Path>() {
         // 先去遍历删除文件
         @Override
         public FileVisitResult visitFile(Path file,
                                  BasicFileAttributes attrs) throws IOException {
            Files.delete(file);
            System.out.printf("文件被删除 : %s%n", file);
            return FileVisitResult.CONTINUE;
         }
         // 再去遍历删除目录
         @Override
         public FileVisitResult postVisitDirectory(Path dir,
                                         IOException exc) throws IOException {
            Files.delete(dir);
            System.out.printf("文件夹被删除: %s%n", dir);
            return FileVisitResult.CONTINUE;
         }
      }
   );
}

@Test
void testDeleteFileDir6() throws IOException {
   createMoreFiles();
   Path path = Paths.get("D:\\data\\test1\\test2");
   try (Stream<Path> walk = Files.walk(path)) {
      walk.sorted(Comparator.reverseOrder())
         .forEach(DeleteFileDir::deleteDirectoryStream);
   }
}
private static void deleteDirectoryStream(Path path) {
   try {
      Files.delete(path);
      System.out.printf("删除文件成功：%s%n",path.toString());
   } catch (IOException e) {
      System.err.printf("无法删除的路径 %s%n%s", path, e);
   }
}

//传统IO递归删除
@Test
void testDeleteFileDir7() throws IOException {
   createMoreFiles();
   File file = new File("D:\\data\\test1\\test2");
   deleteDirectoryLegacyIO(file);
}
private void deleteDirectoryLegacyIO(File file) {
   File[] list = file.listFiles();  //无法做到list多层文件夹数据
   if (list != null) {
      for (File temp : list) {     //先去递归删除子文件夹及子文件
         deleteDirectoryLegacyIO(temp);   //注意这里是递归调用
      }
   }
   if (file.delete()) {     //再删除自己本身的文件夹
      System.out.printf("删除成功 : %s%n", file);
   } else {
      System.err.printf("删除失败 : %s%n", file);
   }
}