在可穿戴应用程序上下载文件

Question

我在我的Moto360智能手表上创建了一个小应用程序来播放从web服务器下载的音频内容。我使用下面的代码片段从给定的URL下载内容。

@Override
protected String doInBackground(String... sUrl) {
    Log.d(TAG, "Downloading file !!!");
    InputStream input = null;
    OutputStream output = null;
    HttpURLConnection connection = null;
    try {
        URL url = new URL(sUrl[0]);
        connection = (HttpURLConnection) url.openConnection();
        connection.connect();

        // expect HTTP 200 OK, so we don't mistakenly save error report
        // instead of the file
        if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
            Log.e(TAG, "Error on http connection !! ");
            return "Server returned HTTP " + connection.getResponseCode()
                    + " " + connection.getResponseMessage();
        }

        // this will be useful to display download percentage
        // might be -1: server did not report the length
        int fileLength = connection.getContentLength();

        // download the file
        input = connection.getInputStream();
        output = new FileOutputStream("/sdcard/file_name.extension");

        byte data[] = new byte[4096];
        long total = 0;
        int count;
        while ((count = input.read(data)) != -1) {
            // allow canceling with back button
            if (isCancelled()) {
                input.close();
                return null;
            }
            total += count;
            // publishing the progress....
            if (fileLength > 0) // only if total length is known
                publishProgress((int) (total * 100 / fileLength));
            output.write(data, 0, count);
        }
    } catch (Exception e) {
        Log.e(TAG, "exception : " + e);
        return e.toString();
    } finally {
        try {
            if (output != null) {
                Log.d(TAG, "download finished!");
                output.close();
            }
            if (input != null)
                input.close();
        } catch (IOException ignored) {
        }

        if (connection != null)
            connection.disconnect();
    }
    return null;
}

但我有一个超时连接：

08-06 16:22:06.345  17925-17941/com.example.ile14017.moto360 E/DownloadTask﹕ exception : java.net.ConnectException: failed to connect to api.europe1.fr/85.116.42.56 (port 80): connect failed: ETIMEDOUT (Connection timed out)

我试图更改连接超时值(setConnectTimeout方法)，但结果是相同的。下载的文件大小约为2Mo。

Answer 1

你的手表(通过BT)和你的手机相连吗？如果是这样的话，那么即使在手表上设置wifi，您的手表也无法使用URLConnection进行网络呼叫。您需要考虑这种情况，并使用您的手机为您做下载，然后转移文件到您的手表使用，例如，ChannelApi。