在Java中复制数据的速度更快？

Question

我被赋予了从服务器复制数据的任务.我正在使用BufferedInputStream和输出流来复制数据,我正在逐字节地进行.即使它正在运行但复制数据需要花费很长时间,因为其中一些数据是100的MB,所以肯定它不会起作用.任何人都可以建议我Byte副本的Byte副本,以便我的代码可以复制几百MB的文件.缓冲区是2048.

以下是我的代码的样子:

static void copyFiles(SmbFile[] files, String parent) throws IOException {

  SmbFileInputStream input = null;
  FileOutputStream output = null;
  BufferedInputStream buf_input = null;
  try {
    for (SmbFile f : files) {
      System.out.println("Working on files :" + f.getName());
      if (f.isDirectory()) {

        File folderToBeCreated = new File(parent+f.getName());
        if (!folderToBeCreated.exists()) {
          folderToBeCreated.mkdir();
          System.out.println("Folder name " + parent
                + f.getName() + "has been created");
        } else {
          System.out.println("exists");

        }

        copyFiles(f.listFiles(), parent +  f.getName());
      } else {

        input = (SmbFileInputStream) f.getInputStream();

        buf_input = new BufferedInputStream(input, BUFFER);

        File t = new File(parent + f.getName());
        if (!t.exists()) {
          t.createNewFile();
        }
        output = new FileOutputStream(t);

        int c;

        int count;
        byte data[] = new byte[BUFFER];

        while ((count = buf_input.read(data, 0, BUFFER)) != -1) {
          output.write(data, 0, count);
        }
      }
    }
  } catch (IOException e) {
    e.printStackTrace();

  } finally {
    if (input != null) {
      input.close();
    }
    if (output != null) {
      output.close();
    }
  }
}

Answer 1

这是一篇优秀帖子的链接,解释了如何使用nio频道制作流的副本.它引入了一个帮助方法ChannelTools.fastChannelCopy,可以让你像这样复制流:

final InputStream input = new FileInputStream(inputFile);
final OutputStream output = new FileOutputStream(outputFile);
final ReadableByteChannel inputChannel = Channels.newChannel(input);
final WriteableByteChannel outputChannel = Channels.newChannel(output);
ChannelTools.fastChannelCopy(inputChannel, outputChannel);
inputChannel.close();
outputChannel.close()