Apps often have a need to offer one or more of their files to another app. For example, an image gallery may want to offer files to image editors, or a file management app may want to allow users to copy and paste files between areas in external storage. One way a sending app can share a file is to respond to a request from the receiving app.
In all cases, the only secure way to offer a file from your app to another app is to send the
receiving app the file's content URI and grant temporary access permissions to that URI.
Content URIs with temporary URI access permissions are secure because they apply only to the
app that receives the URI, and they expire automatically. The Android
FileProvider component provides the method
generating a file's content URI.
If you want to share small amounts of text or numeric data between apps, you should send an
Intent that contains the data. To learn how to send simple data with an
Intent, see the training class
Sharing Simple Data.
This class explains how to securely share files from your app to another app using content URIs
generated by the Android
FileProvider component and
temporary permissions that you grant to the receiving app for the content URI.
FileProviderto retrieve file information including MIME type and file size.