java - Email from internal storage

Question

On my application I write a file to the internal storage as covered on android developer. Then later on I wish to email the file I wrote into the internal storage. Here is my code and the error I am getting, any help will be appreciated.

FileOutputStream fos = openFileOutput(xmlFilename, MODE_PRIVATE);
fos.write(xml.getBytes());
fos.close();
Intent intent = new Intent(android.content.Intent.ACTION_SEND);
intent.setType("text/plain");
...
Uri uri = Uri.fromFile(new File(xmlFilename));
intent.putExtra(android.content.Intent.EXTRA_STREAM, uri);
startActivity(Intent.createChooser(intent, "Send eMail.."));

And the error is

file:// attachment path must point to file://mnt/sdcard. Ignoring attachment file://...

Answer 1

I think you may have found a bug (or at least unnecessary limitation) in the android Gmail client. I was able to work around it, but it strikes me as too implementation specific, and would need a little more work to be portable:

First CommonsWare is very much correct about needing to make the file world readable:

fos = openFileOutput(xmlFilename, MODE_WORLD_READABLE);

Next, we need to work around Gmail's insistence on the /mnt/sdcard (or implementation specific equivalent?) path:

Uri uri = Uri.fromFile(new File("/mnt/sdcard/../.."+getFilesDir()+"/"+xmlFilename));

At least on my modified Gingerbread device, this is letting me Gmail an attachment from private storage to myself, and see the contents using the preview button when I receive it. But I don't feel very "good" about having to do this to make it work, and who knows what would happen with another version of Gmail or another email client or a phone which mounts the external storage elsewhere.