如何从Media真实路径获取可写DocumentFile Uri？

Question

I have a situation in Lollipop where I have:

1. Directory tree ( DocumentFile ) which is granted from user.

2. A collection of audio files that need to modify retrieved from media provider.

    Uri mediaUri = Uri.withAppendedPath(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, "45"); 

Then, how to write a stream into one of those files?

I think, this https://stackoverflow.com/a/30514269/615025 gives a work around. Copy bytes of the file to cache directory, do modification on the temporary file and then copy the bytes back to the original file.

DocumentFile is a new mechanism which allows us to modify files in Lollipop. It is not the same case with this post how to get contact photo URI Thanks

Answer 1

You can open an outputStream directly from a Uri using ContentResolver.openOutputStream(Uri) For example,

OutputStream fos;
fos = new BufferedOutputStream(context.getContentResolver().openOutputStream(uri));

Optionally, openOutputStream takes a string to specify mode. ie

openOutputStream(uri, "w");

to write or

openOutputStream(uri, "wa");

to append.