如何加速文件存储访问？

Question

我正在尝试获取包含用户内部存储上的MP3文件的所有文件夹的列表。

这里是我打电话用于此目的的递归函数 -

public void listAllMusicFiles(String pathToDirectory) { 
     String lastFolderPath = ""; 
     int mp3Count = 0; 
     File f = new File(pathToDirectory); 
     File[] files = f.listFiles(); 
     for (File inFile : files) { 
      if (inFile.isDirectory()) { 
       //reset last folder path 
       lastFolderPath = ""; 
       Log.d("Directory ", inFile.getPath()); 
       listAllMusicFiles(inFile.getPath()); 
      } else { 
       if (inFile.getAbsolutePath().endsWith(".mp3") || inFile.getAbsolutePath().endsWith(".MP3")) { 
        mp3Count++; 
        Log.wtf("MP3 Count", mp3Count + " "); 

        //add each folder only once 
        String folderName = inFile.getParentFile().getName(); 
        String folderPath = inFile.getParentFile().getPath(); 
        Log.e("FOUND in", folderPath); 

        //create a new Folder object 
        Folder currentFolder = new Folder(folderName, folderPath, mp3Count + ""); 

        if (!lastFolderPath.equals(folderPath)) { 
         Log.d("NEW", folderPath); 
         lastFolderPath = folderPath; 
         folderArrayList.add(currentFolder); 
        } else { 
         Log.d("OLD", folderPath); 
         //find a Folder object in folderArrayList where the object's path matches current folderPath 
         for (Folder folder : folderArrayList) { 
          String currentPath = folder.getFolder_Path(); 
          if (currentPath.equals(folderPath)) { 
           //found a match 
           //update count 
           folder.setFolder_Song_Count(mp3Count + ""); 
          } 
         } 
        } 
       } 
      } 
     } 
    } 

当我运行我的设备上运行此代码，我能列出所需文件夹中RecyclerView，但随着延迟大约6-7秒。

我已经将此任务移至AsyncTask中，以便我的UIThread不会由于此密集操作而挂起。

但是当谈到提高文件系统性能时，我完全不知所措。请帮助。谢谢 ！

Answer 1

而是在一个ArrayList，并在下一步通过完整列表迭代存储currentFolder找到该文件夹​​和更新的价值，你可以简单地使用HashMap中这样

HashMap<String, Folder> folders = new HashMap<>(); 

    public void listAllMusicFiles(String pathToDirectory) { 

     int mp3Count = 0; 
     File f = new File(pathToDirectory); 
     File[] files = f.listFiles(); 

     Folder folder; 
     String folderName, folderPath; 

     for (File inFile : files) { 
      if (inFile.isDirectory()) { 
       //reset last folder path 
       Log.d("Directory ", inFile.getPath()); 
       listAllMusicFiles(inFile.getPath()); 
      } else { 
       if (inFile.getAbsolutePath().endsWith(".mp3") || inFile.getAbsolutePath().endsWith(".MP3")) { 
        mp3Count++; 
        Log.wtf("MP3 Count", mp3Count + " "); 

        //add each folder only once 
        folderName = inFile.getParentFile().getName(); 
        folderPath = inFile.getParentFile().getPath(); 

        Log.e("FOUND in", folderPath); 

        if (folders.containsKey(folderPath)) { 

         folder = folders.get(folderPath); 
         folder.setFolder_Song_Count(mp3Count + ""); 
         folders.put(folderPath, folder); 
        } else { 

         folder = new Folder(folderName, folderPath, mp3Count + ""); 
         folders.put(folderPath, folder); 
        } 

       } 
      } 
     } 
    }