问如何引用手机档案结构

EN

     /* Create a list of URIs, get a File,
      * and set its permissions
      */
    private Uri[] mFileUris = new Uri[10];
    String transferFile = "transferimage.jpg";
    File extDir = getExternalFilesDir(null);
    File requestFile = new File(extDir, transferFile);
    requestFile.setReadable(true, false);
    // Get a URI for the File and add it to the list of URIs
    fileUri = Uri.fromFile(requestFile);
    if (fileUri != null) {
        mFileUris[0] = fileUri;
    } else {
        Log.e("My Activity", "No File URI available for file.");
    }