在Android中下载图像URL时出现FileNotFoundException

Question

我在Android中下载图片网址时出现问题，我有一个Facebook相册图片网址，当我尝试将图片下载到移动存储时，我收到了Exception FileNotFound。代码如下。任何人有解决方案请帮助我。 感谢Advance。请不要评价我。

    protected Void doInBackground(String... strings) {
        try
        {
            URL url = new URL(photos.get(1).getPictureUrl());
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("POST");
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.connect();

            File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_DCIM), "Image");
            if (! mediaStorageDir.exists()){
                if (! mediaStorageDir.mkdirs()){
                    mediaStorageDir   =   new File("storage/emmc"+File.separator);
                }

            }
            String filename="downloadedFile.png";
            Log.i("Local filename:",""+filename);
            File file = new File(mediaStorageDir,filename);
            if(file.createNewFile())
            {
                file.createNewFile();
            }
            FileOutputStream fileOutput = new FileOutputStream(file);
            InputStream inputStream = urlConnection.getInputStream();
            int totalSize = urlConnection.getContentLength();
            int downloadedSize = 0;
            byte[] buffer = new byte[1024];
            int bufferLength = 0;
            while ( (bufferLength = inputStream.read(buffer)) > 0 )
            {
                fileOutput.write(buffer, 0, bufferLength);
                downloadedSize += bufferLength;
                Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
            }
            fileOutput.close();
            if(downloadedSize==totalSize) filepath=file.getPath();
        }
        catch (MalformedURLException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            filepath=null;
            e.printStackTrace();
        }

        Log.i("filepath:"," "+filepath) ;
        return null;
    }