我的下载视频代码在Android 4.0中不起作用

Question

我已经完成了应用程序的视频文件下载代码及其2.3.3版本的工作状态，但它在android 4.0中无法正常工作，它给出的错误如java.io.FileNotFoundException 任何人都可以帮我解决这个问题吗？ 提前致谢

public void video_download(String urlstring, String Name) {

    URL url;
    try {
        url = new URL(urlstring);
        HttpURLConnection c = (HttpURLConnection) url.openConnection();
        c.setRequestMethod("GET");
        c.setDoOutput(true);
        c.connect();

        String PATH = Environment.getExternalStorageDirectory()
                + "/application/";
        Log.v("PATH", "PATH: " + PATH);
        File file = new File(PATH);
        file.mkdirs();
        String fileName;
        fileName = Name + ".mp4";

        File outputFile = new File(file, fileName);
        FileOutputStream fos = new FileOutputStream(outputFile);

        InputStream is = c.getInputStream();

        byte[] buffer = new byte[1024];
        int len1 = 0;
        while ((len1 = is.read(buffer)) != -1) {
            fos.write(buffer, 0, len1);
        }
        fos.close();
        is.close();
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}