Question

我想在使用DownloadManager点击按钮时更新应用程序的sqlite数据库。

但它说“java.lang.IllegalArgumentException：Not a file URI：/data/user/0/com.example.laudien.listviewtesting/databases/Employees”

我做错了什么？我需要获得许可吗？互联网许可已经在清单中。

以下是我的updateDb（）方法的代码：

private void updateDb() {
    DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE); // create download manager
    DownloadFinishedReceiver receiver = new DownloadFinishedReceiver(); // create broadcast receiver
    registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE)); // register the receiver
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(DATABASE_URL)); // create a download request

    // delete database file if it exists
    File databaseFile = new File(getDatabasePath(DATABASE_NAME).getAbsolutePath());
    if(databaseFile.exists())
        databaseFile.delete();

    request//.setNotificationVisibility(DownloadManager.Request.VISIBILITY_HIDDEN) // not visible
        .setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI) // only via wifi
        .setDestinationUri(Uri.parse("file:" + getDatabasePath(DATABASE_NAME).getAbsolutePath())); // set path in app dir
    downloadManager.enqueue(request); // enqueue the download request
}

Answer 1

您的路径/data/user/0/com.example.laudien.listviewtesting是您应用的私密内存。您是使用getFilesDir()获得的。其他应用无法访问。包括下载管理器。请改用getExternalStorageDirectory()给出的外部记忆。

Answer 2

对于想要将敏感文件下载到应用的私有文件夹的任何人，我不得不说下载管理器无法访问内部存储中的这些文件夹。但解决方案是在广播接收器中移动下载的文件。例如将这样的行放在 BroadcastReceiver 中：

String destinationFileName = "test.mp4";
String filePath = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
copyFile(Uri.parse(filePath).getPath(), context.getFilesDir() + "/" + destinationFileName);

和 copyFile 是这样的方法：

private void copyFile(String inFileName, String outFileName) throws IOException {

    InputStream myInput = new FileInputStream(inFileName);

    OutputStream myOutput = new FileOutputStream(outFileName);

    // Transfer bytes from the input file to the output file
    byte[] myBuffer = new byte[1024];
    int length;
    while ((length = myInput.read(myBuffer)) > 0)
        myOutput.write(myBuffer, 0, length);

    // Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close();
}

将数据库文件下载到app目录

2 个答案: