Android open InputStream from relative uri to ACTION_OPEN_DOCUMENT?

问题

I'am trying to open multiple files relative to a json configuration file in android 4.4 (api level 19), I used

Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType({mime});
this.startActivityForResult(intent, {code});

to let the user find te configuration file, and from there open multiple files that I know the path from the config file.

But i get

Caused by: java.lang.SecurityException: 
Permission Denial: reading com.android.providers.downloads.DownloadStorageProvider
uri content://com.android.providers.downloads.documents/document/raw:/storage/emulated/0/Download/{relative file}
requires that you obtain access using ACTION_OPEN_DOCUMENT or related APIs

I dont want to use user interfaces to open the other files, so I tried adding the following permissions without getting any results

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MANAGE_DOCUMENTS "/>

I would rather have the files separated and not in a blob or a zip file

回答1:

ACTION_OPEN_DOCUMENT only gives you access to exactly the file (or files, if you use EXTRA_ALLOW_MULTIPLE) that the user selects.

You can use ACTION_OPEN_DOCUMENT_TREE to allow the user to select a folder - you'll then get access to all files in that folder (and their subfolders).

回答2:

If you need to let the user choose multiple files from a file chooser, you can do the following:

It's part of my app, you can adjust it for your needs. This works starting from API 18

private void openFileChooser() {
    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
    i.setType("*/*");
    i.putExtra(Intent.EXTRA_LOCAL_ONLY, true);
    i.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
    startActivityForResult(i, REQUEST_CODE_DOC_ALL_FILES);
}

Then here is how you get the selected Uris:

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

if (requestCode == REQUEST_CODE_DOC_ALL_FILES && resultCode == Activity.RESULT_OK) {

        if (data == null || (data.getData() == null && data.getClipData() == null)) {
            Toast.makeText(getContext(), R.string.invalid_source, Toast.LENGTH_SHORT).show();
            return;
        }


        //get result after user action (selecting files) and transform it into array of Uris
        Uri[] uriPaths;
        if (data.getData() != null) { // only one uri was selected by user
            uriPaths = new Uri[1];
            uriPaths[0] = data.getData();
        } else if (data.getClipData() != null) {
            int selectedCount = data.getClipData().getItemCount();
            uriPaths = new Uri[selectedCount];
            for (int i = 0; i < selectedCount; i++) {
                uriPaths[i] = data.getClipData().getItemAt(i).getUri();
            }
        } 
}

来源：https://stackoverflow.com/questions/53246026/android-open-inputstream-from-relative-uri-to-action-open-document