如何使用Java NIO通道传输复制文件？

通过JAVA NIO 通道传输拷贝文件

方式一

 /**
   * 通过JAVA NIO 通道传输拷贝文件
   *
   * @param sourcePath 源文件路径
   * @param targetPath 目标文件路径
   */
  public static void copyFileByChannelTransfer(String sourcePath, String targetPath) {
    FileChannel inChannel = null;
    FileChannel outChannel = null;
    try {
      //获取通道
      inChannel = FileChannel.open(Paths.get(sourcePath), StandardOpenOption.READ);
      outChannel = FileChannel.open(Paths.get(targetPath),StandardOpenOption.WRITE,StandardOpenOption.READ,StandardOpenOption.CREATE);

      inChannel.transferTo(0,inChannel.size(),outChannel);
    } catch (IOException e) {
      e.printStackTrace();
    }finally {
      //关闭流
      try {
        if (outChannel != null) {
          outChannel.close();
        }
        if (inChannel != null) {
          inChannel.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

方式二

 /**
   * 通过JAVA NIO 通道传输拷贝文件
   *
   * @param sourcePath 源文件路径
   * @param targetPath 目标文件路径
   */
  public static void copyFileByChannelTransfer2(String sourcePath, String targetPath) {
    FileInputStream fis = null;
    FileOutputStream fos = null;
    FileChannel inChannel = null;
    FileChannel outChannel = null;
    try {
      fis = new FileInputStream(sourcePath);
      fos = new FileOutputStream(targetPath);

      //获取通道
      inChannel = fis.getChannel();
      outChannel = fos.getChannel();

      inChannel.transferTo(0,inChannel.size(),outChannel);
    } catch (IOException e) {
      e.printStackTrace();
    }finally {
      //关闭流
      try {
        if (outChannel != null) {
          outChannel.close();
        }
        if (inChannel != null) {
          inChannel.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

使用示例

String source = "e:\\demo\\纵天神帝.txt";
    String target = "e:\\demo\\";
    long time1 = System.currentTimeMillis();
    copyFileByStream(source, target + "1.txt");
    System.out.println("通过字节流实现文件的拷贝耗时：" + (System.currentTimeMillis() - time1));

    long time2 = System.currentTimeMillis();
    copyFileByReaderAndWriter(source, target + "2.txt");
    System.out.println("通过字符流实现文件的拷贝耗时：" + (System.currentTimeMillis() - time2));

    long time3 = System.currentTimeMillis();
    copyFileByBuffered(source, target + "3.txt");
    System.out.println("通过字节缓冲流实现文件的拷贝耗时：" + (System.currentTimeMillis() - time3));

    long time4 = System.currentTimeMillis();
    copyFileByBufferedChar(source, target + "4.txt");
    System.out.println("通过字符缓冲流实现文件的拷贝耗时：" + (System.currentTimeMillis() - time4));

    long time5 = System.currentTimeMillis();
    copyFileByChannel(source, target + "5.txt");
    System.out.println("通过JAVA NIO通道（非直接缓冲区）实现文件的拷贝耗时：" + (System.currentTimeMillis() - time5));

    long time6 = System.currentTimeMillis();
    copyFileByChannelBufferd(source, target + "6.txt");
    System.out.println("通过JAVA NIO通道（直接缓冲区）实现文件的拷贝耗时：" + (System.currentTimeMillis() - time6));

    long time7 = System.currentTimeMillis();
    copyFileByChannelTransfer(source, target + "7.txt");
    System.out.println("通过JAVA NIO通道传输实现文件的拷贝耗时：" + (System.currentTimeMillis() - time7));

    long time8 = System.currentTimeMillis();
    copyFileByChannelTransfer(source, target + "8.txt");
    System.out.println("通过JAVA NIO通道传输2实现文件的拷贝耗时：" + (System.currentTimeMillis() - time8));