无法在Android上下载文件，而在PC上下载正常(亚马逊)

Question

有个奇怪的问题。Url: https://s3.amazonaws.com/myappdata/msg/171401089927.mp3(不再可用)的文件在PC上下载ok及其mp3文件。但是当我尝试在Android FOA上DL它时，我得到内容类型"application/xml"而不是"audio/mpeg"，当下载开始时，我得到:

05-30 12:13:44.478: E/PlayerService(28023): java.io.FileNotFoundException: https://s3.amazonaws.com/myappdata/msg/171401089927.mp3
05-30 12:13:44.478: E/PlayerService(28023):     at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177)
05-30 12:13:44.478: E/PlayerService(28023):     at libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:270)

用于DL的代码:

    /**
     * Download the url stream to a temporary location
     */
    public void downloadAudioIncrement(String mediaUrl) throws IOException {
        Log.i(TAG, "downloadAudioIncrement(): mediaUrl: "+mediaUrl+"ncacheDir: "+cacheDir);
        URL url = null;
        try {
            url = new URL(mediaUrl);
        } catch (MalformedURLException e) {
            e.printStackTrace();
            throw new IOException("Unable to create InputStream for mediaUrl:" + mediaUrl);
        }
        // this file will represent whole downloaded song
        mp3FileDownloaded = new File(cacheDir, mp3FileName);
        if (!mp3FileDownloaded.exists())
            //FileUtils.makeDirsForFile(mp3FileDownloaded);
            try{
                mp3FileDownloaded.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
        }
        if (!mp3FileDownloaded.canWrite())
            throw new IOException("Can't open temporary file for writing");
        HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
        urlConnection.setReadTimeout(1000 * 20);
        urlConnection.setConnectTimeout(1000 * 5);
        urlConnection.setDoInput(true);
        urlConnection.setDoOutput(true);
        int mp3BytesSize = urlConnection.getContentLength();
        // final String
        // contentLengthStr=urlConnection.getHeaderField("content-length");
        String ctype = urlConnection.getContentType();
        if (ctype == null) {
            ctype = "";
        } else {
            ctype = ctype.toLowerCase(Locale.US);
        }
        // See if we can handle this type
        Log.i(TAG, "Content Type: " + ctype);
        if ( ctype.contains("audio/mpeg") || TextUtils.isEmpty(ctype) ) {
            String temp = urlConnection.getHeaderField(BITRATE_HEADER);
            Log.i(TAG, "Bitrate: " + temp);
            // if (temp != null){
            // bitrate = new Integer(temp).intValue();
            // }
        } else {
            Log.e(TAG, UNSUPPORTED_AUDIO_TYPE+": " + ctype);
//          throw new IOException(UNSUPPORTED_AUDIO_TYPE+": " + ctype);
            // Log.e(TAG, "Or we could not connect to audio");
            // stop();
            // return;
        }
        final InputStream stream = new BufferedInputStream(urlConnection.getInputStream(),8192);
...

就在最后显示的代码行(实例化InputStream流)处引发了上述ioexception。还有其他mp3文件存在于同一位置，他们正在下载没有任何问题，但只有上面提到的url失败。
这里有什么问题吗?

这个问题出现在HTC Rezound的AOS 4.0.4上。在其他设备上，使用AOS 2.3.5一切正常

Answer 1

看起来像

urlConnection.setDoOutput(true);

是问题的根源，因为我没有上传任何数据。一切都很好，因为我评论它。此外，这些FileNotFoundException而获得InputStream对象从HttpURLConnection和Android HttpURLConnection gettinputstream抛出NullPointerException线程可能是有帮助的。