AsyncTask用0B下載的文件

我試圖用AsyncTask下載文件，並且下載的所有文件都有0b。我不知道該怎麼辦。有人可以幫忙嗎？請幫助我，我花了整整一天的時間。我的錯誤在哪裏？我從來沒有使用過AsyncTask，我用例子編寫了這段代碼。AsyncTask用0B下載的文件

一些代碼：

public class DownloadProgramTask extends AsyncTask<Void,Void,Void> { 
    int id; 
    MYDBHelperFromApi mydbHelperFromApi; 
    Program program; 
    List<Asana> asanaList; 

    public DownloadProgramTask(int id, MYDBHelperFromApi mydbHelperFromApi){ 

     this.id = id; 
     this.mydbHelperFromApi = mydbHelperFromApi; 

    } 
    @Override 
    protected Void doInBackground(Void...params) { 

     program = mydbHelperFromApi.getProgramForStart(id); 
     asanaList = program.getAsanasList(); 

     final String FILE_PATH_PROGRAM_VOICE = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Programs/Voice/"+id+"/"; 

     List<String> voiceList = new ArrayList<>(); 
     List<File> fileList = new ArrayList<>(); 
     File dirVoice = new File(FILE_PATH_PROGRAM_VOICE); 
     fileList.add(dirVoice); 
     for (File f:fileList) { 
      if (!f.exists()) 
       f.mkdirs(); 
     } 
     for (Asana a:asanaList) { 

      File voiceFile = new File(dirVoice, a.getPose_id() + ".mp3"); 

      if (!voiceFile.exists()) { 
       voiceList.add(a.getVoice()); 
       download(MYurl.BASE_URL + a.getVoice(), voiceFile.getPath()); 
       Log.e("LINK",MYurl.BASE_URL + a.getVoice()); 
       Log.e("Path voice", "" + voiceFile.getPath()); 

      } 
     } 

     return null; 
    } 
    public void download(String s, String Path_file) { 
     InputStream input = null; 
     OutputStream output = null; 
     HttpURLConnection connection = null; 
     try { 
      URL url = new URL(s); 
      connection = (HttpURLConnection) url.openConnection(); 
      connection.connect(); 

      if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) { 
       Log.d("Something went wrong"," "+s); 
      } 


      int fileLength = connection.getContentLength(); 


      input = connection.getInputStream(); 
      output = new FileOutputStream(Path_file); 

      byte data[] = new byte[4096]; 
      long total = 0; 
      int count; 
      while ((count = input.read(data)) != -1) { 

       if (isCancelled()) { 
        input.close(); 
       } 
       total += count; 

      } 
     } catch (Exception e) { 
      Log.e("Exception", e.toString()); 
     } finally { 
      try { 
       if (output != null) 
        output.close(); 
       if (input != null) 
        input.close(); 
      } catch (IOException ignored) { 
      } 

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

來源

2015-10-15 R.D

是'Log.e（「異常」，e.toString（））之前;'打印你的任何異常？我問，因爲你正在創建一個文件，然後再下載，這將解釋爲什麼你有一個0字節的文件，如果下載導致一些異常。 –

你是哪裏的輸出流寫？

加入這行while循環下載方法：

outputStream.write(data, 0, count);

來源

2015-10-15 15:22:12 dex

你試過關閉FileOutputStream之前進行刷新？

儘量把output.flush();output.close();

try { 
    if (output != null) { 
    output.flush(); 
    output.close(); 
    } 
    if (input != null) 
    input.close(); 
} catch (IOException ignored) { 
}

來源

2015-10-15 15:36:33

AsyncTask用0B下載的文件

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