未知网址 content://downloads/my_downloads

Question

我正在使用下载管理器下载一些多媒体文件并对它们进行分类。我也在使用Crashlytics，这是我在不同设备和不同版本的Android上经常遇到的错误:

java.lang.IllegalArgumentException: Unknown URL content://downloads/my_downloads
   at android.content.ContentResolver.insert(ContentResolver.java:862)
   at android.app.DownloadManager.enqueue(DownloadManager.java:1252)
   at com.myapp.LessonFragment$DownloadClickListener.onClick(SourceFile:570)
   at android.view.View.performClick(View.java:4262)
   at android.view.View$PerformClick.run(View.java:17351)
   at android.os.Handler.handleCallback(Handler.java:615)
   at android.os.Handler.dispatchMessage(Handler.java:92)
   at android.os.Looper.loop(Looper.java:137)
   at android.app.ActivityThread.main(ActivityThread.java:4921)
   at java.lang.reflect.Method.invokeNative(Method.java)
   at java.lang.reflect.Method.invoke(Method.java:511)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
   at dalvik.system.NativeStart.main(NativeStart.java)

你可以在下面看到我的代码:

private class DownloadClickListener implements View.OnClickListener {
    @Override
    public void onClick(View view) {
        // Check if download manager available before request
        if (!DownloadHelper.isDownloadManagerAvailable(getActivity())) {
            // Build custom alert dialog
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            builder.setMessage(R.string.download_manager_disabled);
            builder.setCancelable(false);
            builder.setPositiveButton(R.string.ok, (dialog, which) -> {
                dialog.dismiss();
            });
            // Create and display alert dialog
            AlertDialog dialog = builder.create();
            dialog.show();
            return;
        }

        // Display short toast on download clicked
        Toast.makeText(getActivity(), R.string.lesson_download_start, Toast.LENGTH_SHORT).show();

        // Get attach from view tag
        Attache attache = (Attache) view.getTag();

        // Get lesson using lesson id
        Lesson lesson = new Select().from(Lesson.class)
                .where(Condition.column("id").is(attache.getLessonId()))
                .querySingle();

        // Set file name from url and attache name
        Uri uri = Uri.parse(attache.getFile());
        String fileName = attache.getName() + '.'
                + MimeTypeMap.getFileExtensionFromUrl(attache.getFile());

        // Check if path directory not exist and create it
        String filePath = Environment.getExternalStorageDirectory() + "/myapp/" + lesson.getTitle() + "/";
        File path = new File(filePath);
        if (!path.exists() || !path.isDirectory()) {
            if (!path.mkdirs()) {
                Timber.e("Could not create path directory.");
            }
        }

        // Check if file exist and then delete it
        File file = new File(filePath, fileName);
        if (file.exists() && file.isFile()) {
            if (file.delete()) {
                Timber.v("%s just deleted.", fileName);
            }
        }

        // Create download manager request using url
        DownloadManager.Request request = new DownloadManager.Request(uri);
        request.setTitle(attache.getName());
        request.setDestinationInExternalPublicDir("/myapp/" + lesson.getTitle(), fileName);

        // Using DownloadManager for download attache file
        DownloadManager manager = (DownloadManager) getActivity().getSystemService(Context.DOWNLOAD_SERVICE);
        manager.enqueue(request);
    }
}

Answer 1

异常是由禁用的下载管理器引起的。没有办法直接激活/停用下载管理器，因为它是系统应用程序，我们没有访问它的权限。

唯一的替代方法是将用户重定向到下载管理器应用程序的设置。

try {
     //Open the specific App Info page:
     Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
     intent.setData(Uri.parse("package:" + "com.android.providers.downloads"));
     startActivity(intent);

} catch ( ActivityNotFoundException e ) {
     e.printStackTrace();

     //Open the generic Apps page:
     Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_APPLICATIONS_SETTINGS);
     startActivity(intent);
}

Answer 2

我遇到了异常java.lang.IllegalArgumentException：未知的URI：内容：//下载/public_downloads/7505在从下载中获取doucuments。这个解决方案对我有用。

else if (isDownloadsDocument(uri)) {
            String fileName = getFilePath(context, uri);
            if (fileName != null) {
                return Environment.getExternalStorageDirectory().toString() + "/Download/" + fileName;
            }

            String id = DocumentsContract.getDocumentId(uri);
            if (id.startsWith("raw:")) {
                id = id.replaceFirst("raw:", "");
                File file = new File(id);
                if (file.exists())
                    return id;
            }

            final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
            return getDataColumn(context, contentUri, null, null);
        }

这是用于获取filepath的方法

   public static String getFilePath(Context context, Uri uri) {

    Cursor cursor = null;
    final String[] projection = {
            MediaStore.MediaColumns.DISPLAY_NAME
    };

    try {
        cursor = context.getContentResolver().query(uri, projection, null, null,
                null);
        if (cursor != null && cursor.moveToFirst()) {
            final int index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DISPLAY_NAME);
            return cursor.getString(index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}

Answer 3

对于那些收到错误未知URI： content：//down/public_downloads的人。我设法通过在这个答案中得到@Common sware给出的提示来解决这个问题。我在GitHub上找到了FileUtils类。这里InputStream方法用于从下载目录中获取文件。

 // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);

                if (id != null && id.startsWith("raw:")) {
                    return id.substring(4);
                }

                String[] contentUriPrefixesToTry = new String[]{
                        "content://downloads/public_downloads",
                        "content://downloads/my_downloads",
                        "content://downloads/all_downloads"
                };

                for (String contentUriPrefix : contentUriPrefixesToTry) {
                    Uri contentUri = ContentUris.withAppendedId(Uri.parse(contentUriPrefix), Long.valueOf(id));
                    try {
                        String path = getDataColumn(context, contentUri, null, null);
                        if (path != null) {
                            return path;
                        }
                    } catch (Exception e) {}
                }

                // path could not be retrieved using ContentResolver, therefore copy file to accessible cache using streams
                String fileName = getFileName(context, uri);
                File cacheDir = getDocumentCacheDir(context);
                File file = generateFileName(fileName, cacheDir);
                String destinationPath = null;
                if (file != null) {
                    destinationPath = file.getAbsolutePath();
                    saveFileFromUri(context, uri, destinationPath);
                }

                return destinationPath;
            }