android - 跟踪复制文件的进度

Question

我正在尝试跟踪压缩进度。 ATM 我是这样做的:

public static void compressGzipTest(final OutputStream os, final File source) throws CompressorException,
            IOException
    {
        final CountingInputStream cis = new CountingInputStream(new FileInputStream(source));
        final GzipCompressorOutputStream gzipOut = (GzipCompressorOutputStream) new CompressorStreamFactory()
                .createCompressorOutputStream(CompressorStreamFactory.GZIP,os);

        new Thread() {
            public void run()
            {
                try
                {
                    long fileSize = source.length();

                    while (fileSize > cis.getBytesRead())
                    {
                        Thread.sleep(1000);
                        System.out.println(cis.getBytesRead() / (fileSize / 100.0));
                    }
                }
                catch (Exception ex)
                {
                    ex.printStackTrace();
                }
            }
        }.start();

        IOUtils.copy(cis,gzipOut);
    }

这工作正常，但我需要线程，它提供有关进度的反馈，而不是在此方法中实现，而是在调用它时(以便在 Android 设备上创建类似进度条的东西)。所以这更像是一个架构问题。关于如何解决这个问题的任何想法？

Answer 1

我同时通过添加一个接口(interface)作为参数来覆盖 IOUtils.copy() 来解决它:

public static long copy(final InputStream input, final OutputStream output, int buffersize,
        ProgressListener listener) throws IOException
{
    final byte[] buffer = new byte[buffersize];
    int n = 0;
    long count = 0;
    while (-1 != (n = input.read(buffer)))
    {
        output.write(buffer,0,n);
        count += n;
        listener.onProgress(n);
    }
    return count;
}

然后被这样的东西调用

copy(input, output, 4096, new ProgressListener() {

                long totalCounter = 0;

                DecimalFormat f = new DecimalFormat("#0.00");

                @Override
                public void onProgress(long bytesRead)
                {
                    totalCounter += bytesRead;
                    System.out.println(f.format(totalCounter / (fileSize / 100.0)));
                }
            });

我现在面临的唯一挑战是限制控制台上的输出，不是针对每个字节[4096]，而是针对每两兆字节。我试过这样的事情:

while (-1 != (n = input.read(buffer)))
    {
        output.write(buffer,0,n);
        count += n;
        while(n % 2097152 == 0)
        {
          listener.onProgress(n);
        }
    }
    return count;

但这根本没有给我任何输出