如何从url下载Android文件中的mp3文件并将其保存在SD卡中？ 这是我正在使用的代码

Question

public void DownloadFromUrl(String imageURL, String fileName) {  
  //this is the downloader method
  try {
       URL url = new URL("http://picosong.com/wvaV");
       File file = new File(fileName);

       long startTime = System.currentTimeMillis();
       Log.d("ImageManager", "download begining");
                    Log.d("ImageManager", "download url:" + url);
                    Log.d("ImageManager", "downloaded file name:" + fileName);
                    /* Open a connection to that URL. */
                    URLConnection ucon = url.openConnection();

                    /*
                     * Define InputStreams to read from the URLConnection.
                     */
                    InputStream is = ucon.getInputStream();
                    BufferedInputStream bis = new BufferedInputStream(is);

                    /*
                     * Read bytes to the Buffer until there is nothing more to read(-1).
                     */
                    ByteArrayBuffer baf = new ByteArrayBuffer(50);
                    int current = 0;
                    while ((current = bis.read()) != -1) {
                            baf.append((byte) current);
                    }

                    /* Convert the Bytes read to a String. */
                    FileOutputStream fos = new FileOutputStream(file);
                    fos.write(baf.toByteArray());
                    fos.close();
                    Log.d("ImageManager", "download ready in"
                                    + ((System.currentTimeMillis() - startTime) / 1000)
                                    + " sec");

            } catch (IOException e) {
                    Log.d("ImageManager", "Error: " + e);
            } 
    }
  }

Answer 1

尝试以下代码下载文件。

private void startDownload() {
    String url = "http://farm1.static.flickr.com/114/298125983_0e4bf66782_b.jpg";
    new DownloadFileAsync().execute(url);
}

class DownloadFileAsync extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

    @Override
    protected String doInBackground(String... aurl) {
        int count;
        try {
            URL url = new URL(aurl[0]);
            URLConnection conexion = url.openConnection();
            conexion.connect();
            int lenghtOfFile = conexion.getContentLength();
            Log.d("ANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);
            InputStream input = new BufferedInputStream(url.openStream());
            OutputStream output = new FileOutputStream("/sdcard/some_photo_from_gdansk_poland.jpg");
            byte data[] = new byte[1024];
            long total = 0;
            while ((count = input.read(data)) != -1) {
            total += count;
            publishProgress(""+(int)((total*100)/lenghtOfFile));
            output.write(data, 0, count);
        }

        output.flush();
        output.close();
        input.close();
    } catch (Exception e) {}
        return null;
    }

    protected void onProgressUpdate(String... progress) {
        Log.d("ANDRO_ASYNC",progress[0]);
        mProgressDialog.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String unused) {
        dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
    }
}

有关更多信息，请参阅以下链接。

下载文件

Answer 2

试试这个代码

try{

File cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),"Folder Name");
if(!cacheDir.exists())
   cacheDir.mkdirs();

File f=new File(cacheDir,songname+".mp3");
URL url = new URL(yoururl); 

            InputStream input = new BufferedInputStream(url.openStream());
            OutputStream output = new FileOutputStream(f);

            byte data[] = new byte[1024];
            long total = 0;
            int count=0;
            while ((count = input.read(data)) != -1) {
                total++;
                Log.e("while","A"+total);

                output.write(data, 0, count);
            }

            output.flush();
            output.close();
            input.close();
}
Catch(Exception e){e.printStackTrace();}