複製到SD卡打開失敗：ENOENT（沒有這樣的文件或目錄）

Question

我嘗試從資產複製到SD卡 這裏是我的代碼部分

private void CopyAssets(String folder) { 

     File folders = new File(Environment.getExternalStorageDirectory().toString()+"/beatscache/"+folder); 
     folders.mkdirs(); 
     AssetManager assetManager = getAssets(); 
     String[] files = null; 
       try { 
      files = assetManager.list(folder); 
     } catch (IOException e) { 
      Log.e("tag", e.getMessage()); 
     } 

     for(String filename : files) { 
      InputStream in = null; 
      OutputStream out = null; 
      try { 
       in = assetManager.open(folder+"/"+filename); // if files resides inside the "Files" directory itself 
       out = new FileOutputStream(Environment.getExternalStorageDirectory().toString()+"/"+"beatscache"+"/"+folder +"/" + filename); 
       copyFile(in, out); 
       in.close(); 
       in = null; 
       out.flush(); 
       out.close(); 
       out = null; 
      } catch(Exception e) { 
       Log.e("tag", e.getMessage()); 
      } 
     } 
    } 
    private void copyFile(InputStream in, OutputStream out) throws IOException { 
     byte[] buffer = new byte[1024]; 
     int read; 
     while((read = in.read(buffer)) != -1){ 
      out.write(buffer, 0, read); 
     } 
    } 

而且

CopyAssets("bin"); 

日誌顯示

E /標籤（3801）：到/ mnt/SD卡/ beatscache /斌/ alsa_ctl：打開失敗：ENOENT （沒有這樣的文件或二教區長）

我已經給讀取和寫入權限在AndroidManifest.xml 並檢查Environment.MEDIA_MOUNTED.equals（州）返回true。

並且文件夾沒有被創建。

你能告訴我我做錯了嗎？

Answer 1

檢查文件存在與否先再往前有你的內容

final File dir = new File(cEnvironment.getExternalStorageDirectory()+"/beatscache/"+folder +"/"); 
if(dir.exists()==false) 
{ 
dir.mkdirs(); //create folders where write files 
final File file = new File(dir, filename); 
}