使用SeekableByteChannel从不同位置读取一个字符

import java.io.IOException;

import java.nio.ByteBuffer;
/**
时 代 J a v a 公 众 号 提供 
**/

import java.nio.channels.SeekableByteChannel;

import java.nio.charset.Charset;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.StandardOpenOption;

import java.util.EnumSet;


public class Main {

  public static void main(String[] args) {

    Path path = Paths/* from nowjava.com - 时代Java*/

        .get("C:/folder1/folder2/folder4", "test.txt");

    ByteBuffer buffer = ByteBuffer.allocate(1);

    String encoding = System.getProperty("file.encoding");


    try (SeekableByteChannel seekableByteChannel = (Files.newByteChannel(path,

        EnumSet.of(StandardOpenOption.READ)))) {

      seekableByteChannel.position(0);

      System.out.println("Reading one character from position: "

          + seekableByteChannel.position());

      seekableByteChannel.read(buffer);

      buffer.flip();

      System.out.print(Charset.forName(encoding).decode(buffer));

      buffer.rewind();


      // get into the middle

      seekableByteChannel.position(seekableByteChannel.size() / 2);


      System.out.println("\nReading one character from position: "

          + seekableByteChannel.position());

      seekableByteChannel.read(buffer);

      buffer.flip();

      System.out.print(Charset.forName(encoding).decode(buffer));

      buffer.rewind();


      // get to the end

      seekableByteChannel.position(seekableByteChannel.size() - 1);


      System.o