Java关于文件和目录的操作

public static boolean checkFileWritingOn(String fileName) throws Exception{
    long oldLen = 0;
    long newLen = 0;
    File file = new File(fileName);
    while(true){
        newLen = file.length();
        if ((newLen - oldLen) > 0) {
            oldLen = newLen;
            System.out.println(file.length());
            Thread.sleep(10000);
        } else {
            System.out.println("done");
            return true;
        }
    }
}

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{collapse-item label="获取文件创建时间、最后更新时间等" open}

    /**
     * 获取文件的创建时间
     * @param file
     * @return
     */
    public static Date getCreationTime(File file) throws IOException {
        if (file == null) {
            return null;
        }else {
            Path path =  file.toPath();
            BasicFileAttributes attr = Files.readAttributes(path, BasicFileAttributes.class);
            // 创建时间
            Instant instant = attr.creationTime().toInstant();
            Date fordate = Date.from(instant);
            return fordate;
        }

        // 更新时间
        //Instant instant = attr.lastModifiedTime().toInstant();
        // 上次访问时间
        //Instant instant = attr.lastAccessTime().toInstant();
        //String format = DateTimeFormatter.ofPattern("yyyyMMddHHmmss").withZone(ZoneId.systemDefault()).format(instant);
        //return format;

    }

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{collapse-item label="获取某路径下的所有文件/文件夹" open}

    /**
     * 获取路径下的所有文件/文件夹
     * @param rootDir 需要遍历的文件夹路径
     * @param isAddDirectory 是否将子文件夹的路径也添加到list集合中
     * @return
     */
    public static List<String> getAllFile(String rootDir, boolean isAddDirectory){
        List<String> list = new ArrayList<String>();
        File baseFile = new File(rootDir);
        if (baseFile.isFile() || !baseFile.exists()) {
            return list;
        }
        File[] files = baseFile.listFiles();
        for (File file : files) {
            if (file.isDirectory()) {
                if(isAddDirectory){
                    list.add(file.getAbsolutePath());
                }
                list.addAll(getAllFile(file.getAbsolutePath(),isAddDirectory));
            } else {
                list.add(file.getAbsolutePath());
            }
        }
        return list;
    }

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{collapse-item label="复制文件到指定目录" open}

    /**
     * @param filePath
     * @param targetPath
     * @throws IOException
     */
    public static void fileCope(String filePath, String targetPath) throws IOException {
        //获得流
        FileInputStream fileInputStream = new FileInputStream(filePath);

        File targetFile = new File(targetPath);
        //获取父目录
        File parentFile = targetFile.getParentFile();
        //判断是否存在
        if (!parentFile.exists()) {
            // 创建父目录文件夹
            parentFile.mkdirs();
        }
        //判断文件是否存在
        if (!targetFile.exists()) {
            //创建文件
            targetFile.createNewFile();
        }
        //新文件输出流
        FileOutputStream fileOutputStream = new FileOutputStream (targetFile);
        byte[] buffer= new byte[1024];
        int len;
        //将文件流信息读取文件缓存区，如果读取结果不为-1就代表文件没有读取完毕，反之已经读取完毕
        while ((len=fileInputStream.read(buffer))!=-1) {
            fileOutputStream.write(buffer, 0, len);
            fileOutputStream.flush();
        }
        fileInputStream.close();
        fileOutputStream.close();
    }

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