Question

等级：初学者
语言：Java
IDE：Android Studio
案例：在后台连续从多个URL下载多个MP3文件。
问题：循环下载任务以下载所有URL。歌曲确实按以下路径下载，但并未完全下载（每首歌曲的下载时间为3秒/ 4秒，基本上更少）。不知道出什么问题，如果我能得到任何帮助，那将是很好的

从API接收mp3网址
使用以下代码下载它们。（问题）
获取所有路径并将其存储在数据库中

获取路径并连续一个接一个地播放。

private class DownloadTask extends AsyncTask<SongDetails, Integer, String> {
Context context;

public DownloadTask(Context context) {
    this.context = context;
}

@Override
protected void onPreExecute() {
    super.onPreExecute();
    Utilities.showProgressDialog(getActivity(), getFragmentManager());
}

@Override
protected String doInBackground(SongDetails... songDetails) {
    for (SongDetails songs : songDetails
    ) {
        donwloadsong(songs);
    }
    return null;
}

@Override
protected void onPostExecute(String s) {
    super.onPostExecute(s);
    Utilities.dismissProgressDialog();
}
}




 for (SongDetails songs : songDetails
    ) {
        downloadTask(songs);
    }


 public void downloadTask(SongDetails songs){
   HttpURLConnection httpURLConnection = null;
   try {
     URL url = new URL(songs.getUrl());
     httpURLConnection = (HttpURLConnection) url.openConnection();
     httpURLConnection.setRequestMethod("GET");
     httpURLConnection.connect();

    int fileLength = httpURLConnection.getContentLength();
         InputStream inputStream = new 
    BufferedInputStream(url.openStream(), 8192);
    OutputStream outputStream1;
    outputStream1 = new 
    FileOutputStream(Environment.getExternalStorageDirectory() + "/gbeduwarssongs/" + songDetails.getTitle().trim() + ".mp3");
    int count = 0;
         byte data[] = new byte[1024];
    int buffer_length;

    while ((buffer_length = inputStream.read(data)) != -1) {
        outputStream1.write(data, 0, count);
          count += buffer_length;
    }
    outputStream1.flush();
    outputStream1.close();
    inputStream.close();

} catch (Exception e) {
    e.printStackTrace();
    Log.e("Error", "Download Error Exception " + e.getMessage());
} finally {
    if (httpURLConnection != null)
        httpURLConnection.disconnect();
  }
}

Answer 1

宁可在新线程中调用迭代，也要先使用迭代，然后在每次迭代中启动新线程。希望对您有帮助。我正在发布代码以帮助您。

for (SongDetails songs : songDetails) {
        new DownloadTask(pass your song object in constructor).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
    }

，然后在doInBackground中调用您的下载方法。

Answer 2

我愿意为此使用DownloadManager或workmanager。 AsyncTask使用了一个坏主意。 memory leak有问题。 asyncTask仅使用one thread

The same question

在Android中后台下载多个MP3文件

2 个答案: