3.12 Files

Files

判断文件是否存在

	Path path = Paths.get("data/logging.properties");

	boolean pathExists =Files.exists(path, new LinkOption[]{ LinkOption.NOFOLLOW_LINKS});

创建目录

	Path path = Paths.get("data/subdir");

	try {
	    Path newDir = Files.createDirectory(path);
	} catch(FileAlreadyExistsException e){
	    // the directory already exists.
	} catch (IOException e) {
	    //something else went wrong
	    e.printStackTrace();
	}

复制文件

	Path sourcePath      = Paths.get("data/logging.properties");
	Path destinationPath = Paths.get("data/logging-copy.properties");

	try {
		//可以通过StandardCopyOption.REPLACE_EXISTING覆盖文件
	    Files.copy(sourcePath, destinationPath);
	} catch(FileAlreadyExistsException e) {
	    //destination file already exists
	} catch (IOException e) {
	    //something else went wrong
	    e.printStackTrace();
	}

移动重命名文件

	Path sourcePath      = Paths.get("data/logging-copy.properties");
	Path destinationPath = Paths.get("data/subdir/logging-moved.properties");

	try {
	    Files.move(sourcePath, destinationPath,
	            StandardCopyOption.REPLACE_EXISTING);
	} catch (IOException e) {
	    //moving file failed.
	    e.printStackTrace();
	}

删除文件

	Path path = Paths.get("data/subdir/logging-moved.properties");

	try {
	    Files.delete(path);
	} catch (IOException e) {
	    //deleting file failed
	    e.printStackTrace();
	}

递归遍历文件

	Files.walkFileTree(path, new FileVisitor<Path>() {
	  @Override
	  public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
	    System.out.println("pre visit dir:" + dir);
	    return FileVisitResult.CONTINUE;
	  }

	  @Override
	  public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
	    System.out.println("visit file: " + file);
	    return FileVisitResult.CONTINUE;
	  }

	  @Override
	  public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
	    System.out.println("visit file failed: " + file);
	    return FileVisitResult.CONTINUE;
	  }

	  @Override
	  public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
	    System.out.println("post visit directory: " + dir);
	    return FileVisitResult.CONTINUE;
	  }
	});