设置DownloadManager的目标路径

我使用下面的代码,但不知道文件下载到哪里。没有任何文件存储在给定路径。代码中需要什么更正。代码在开头创建文件夹。

  String path = Environment.getExternalStorageDirectory().getPath() + "/Myapp/Videos";
        System.out.println(path);
        File folder = new File(path);
        if (folder.canExecute()) {
            System.out.println("Video  Folder Found");

        } else {
            folder.mkdirs();
        }

        DownloadManager.Request request = new DownloadManager.Request(uri);
        request.setDescription("Selected Video is being downloaded");
        request.allowScanningByMediaScanner();
        request.setTitle("Downloading Video");
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
        request.setDestinationInExternalFilesDir(mContext, null, title + ".mp4");
        DownloadManager manager = (DownloadManager) mContext.getSystemService(Context.DOWNLOAD_SERVICE);
        manager.enqueue(request);

        return null;