Java 文件任意位置讀寫操作（首尾讀寫都可以）

public static void fileOperationInAnyLocation(String filePath)
	{
		Path path = Paths.get(filePath);

		// To check file exist.
		if (!path.toFile().exists())
			throw new IllegalArgumentException("The file path is not exist.");

		ByteBuffer buffer = ByteBuffer.allocate(1024);
		try
		{
			FileChannel channel = FileChannel.open(path, StandardOpenOption.READ, StandardOpenOption.WRITE);
			channel.read(buffer, channel.size() - 1000);
			System.out.println(new String(buffer.array()));

			ByteBuffer writeBuffer = ByteBuffer.allocate(1024);
			writeBuffer.put("111111111111".getBytes());
			channel.write(writeBuffer, 0);

		} catch (IOException e)
		{
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}