NanoHTTPD. Cache InputStream to file and continue streaming

问题

I want to cache data while playing it in MediaPlayer. As I read, there is one way to do it - create own local http server and set local url to MediaPlayer's setDataSource(String path).

I am using NanoHTTPD as a local server. There is code of serve function:


    @Override
    public Response serve(String uri, Method method, Map headers, Map parms, Map files)
    {
        try
        {
            // delete / character
            URL url = new URL(uri.substring(1));
            URLConnection connection = url.openConnection();
            connection.connect();

            File cacheFolder = new File(Environment.getExternalStorageDirectory(), "TracksFlowCacheNew");
            Log.e("RelayServer", "Cache to file " + Utils.md5(url.toExternalForm()));
            RelayInputStream ris = new RelayInputStream(connection.getInputStream(), new FileOutputStream(new File(cacheFolder, Utils.md5(url.toExternalForm()))));


            return new Response(Response.Status.OK, NanoHTTPD.MIME_DEFAULT_BINARY, ris);
        }
        catch(MalformedURLException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch(FileNotFoundException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch(IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return null;
    }

RelayInputStream extending InputStream. I am trying to cache data there:


    private class RelayInputStream extends InputStream
    {
        private InputStream mInputStream = null;
        private OutputStream mOutputStream = null;

        public RelayInputStream(InputStream is, OutputStream os)
        {
            mInputStream = is;
            mOutputStream = os;
        }

        @Override
        public int available() throws IOException
        {
            Log.e("available", "available = " + mInputStream.available());
            mInputStream.mark(mInputStream.available());
            return mInputStream.available();
        }

        @Override
        public int read(byte[] buffer) throws IOException
        {
            Log.e("read", "buffer = " + buffer.toString());
            mOutputStream.write(buffer);
            return mInputStream.read(buffer);
        }

        @Override
        public int read(byte[] buffer, int offset, int length) throws IOException
        {
            Log.e("read", "buffer = " + buffer.toString() + "; offset = " + offset + "; length = " + length);
            mOutputStream.write(buffer, offset, length);
            return mInputStream.read(buffer, offset, length);
        }

        @Override
        public int read() throws IOException
        {
            Log.e("read", "no data");
            byte[] b = new byte[1];
            mInputStream.read(b);
            mOutputStream.write(b);
            mInputStream.close();
            mOutputStream.close();
            return b[0] & 0xff;
        }
    }

But RelayInputStream's available returns only few downloaded bytes. So, there is only little part of data cached and returned to the media player. So, what am I doing wrong? How to forward and cache all stream?

来源：https://stackoverflow.com/questions/17809405/nanohttpd-cache-inputstream-to-file-and-continue-streaming

标签

android

inputstream

NanoHTTPD