How to use support FileProvider for sharing content to other apps?

Question

I\'m looking for a way to correctly share (not OPEN) an internal file with external application using Android Support library\'s FileProvider.

Following the example

Answer 1

Using FileProvider from support library you have to manually grant and revoke permissions(at runtime) for other apps to read specific Uri. Use Context.grantUriPermission and Context.revokeUriPermission methods.

For example:

//grant permision for app with package "packegeName", eg. before starting other app via intent
context.grantUriPermission(packageName, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);

//revoke permisions
context.revokeUriPermission(uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);

As a last resort, if you can't provide package name you can grant the permission to all apps that can handle specific intent:

//grant permisions for all apps that can handle given intent
Intent intent = new Intent();
intent.setAction(Intent.ACTION_SEND);
...
List<ResolveInfo> resInfoList = context.getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
for (ResolveInfo resolveInfo : resInfoList) {
    String packageName = resolveInfo.activityInfo.packageName;
    context.grantUriPermission(packageName, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
}

Alternative method according to the documentation:

• Put the content URI in an Intent by calling setData().
• Next, call the method Intent.setFlags() with either FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION or both.

• Finally, send the Intent to another app. Most often, you do this by calling setResult().

  Permissions granted in an Intent remain in effect while the stack of the receiving Activity is active. When the stack finishes, the
  permissions are automatically removed. Permissions granted to one
  Activity in a client app are automatically extended to other
  components of that app.

Btw. if you need to, you can copy source of FileProvider and change attachInfo method to prevent provider from checking if it is exported.

Answer 2

This solution works for me since OS 4.4. To make it work on all devices I added a workaround for older devices. This ensures that always the safest solution is used.

Manifest.xml:

    <provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="com.package.name.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
    </provider>

file_paths.xml:

<paths>
    <files-path name="app_directory" path="directory/"/>
</paths>

Java:

public static void sendFile(Context context) {
    Intent intent = new Intent(Intent.ACTION_SEND);
    intent.setType("text/plain");
    String dirpath = context.getFilesDir() + File.separator + "directory";
    File file = new File(dirpath + File.separator + "file.txt");
    Uri uri = FileProvider.getUriForFile(context, "com.package.name.fileprovider", file);
    intent.putExtra(Intent.EXTRA_STREAM, uri);
    intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    // Workaround for Android bug.
    // grantUriPermission also needed for KITKAT,
    // see https://code.google.com/p/android/issues/detail?id=76683
    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
        List<ResolveInfo> resInfoList = context.getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
        for (ResolveInfo resolveInfo : resInfoList) {
            String packageName = resolveInfo.activityInfo.packageName;
            context.grantUriPermission(packageName, attachmentUri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
        }
    }
    if (intent.resolveActivity(context.getPackageManager()) != null) {
        context.startActivity(intent);
    }
}

public static void revokeFileReadPermission(Context context) {
    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
        String dirpath = context.getFilesDir() + File.separator + "directory";
        File file = new File(dirpath + File.separator + "file.txt");
        Uri uri = FileProvider.getUriForFile(context, "com.package.name.fileprovider", file);
        context.revokeUriPermission(uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
    }
}

The permission is revoked with revokeFileReadPermission() in the onResume and onDestroy() methods of the Fragment or the Activity.

Answer 3

As far as I can tell this will only work on newer versions of Android, so you will probably have to figure out a different way to do it. This solution works for me on 4.4, but not on 4.0 or 2.3.3, so this will not be a useful way to go about sharing content for an app that's meant to run on any Android device.

In manifest.xml:

<provider
    android:name="android.support.v4.content.FileProvider"
    android:authorities="com.mydomain.myapp.SharingActivity"
    android:exported="false"
    android:grantUriPermissions="true">
    <meta-data
        android:name="android.support.FILE_PROVIDER_PATHS"
        android:resource="@xml/file_paths" />
</provider>

Take careful note of how you specify the authorities. You must specify the activity from which you will create the URI and launch the share intent, in this case the activity is called SharingActivity. This requirement is not obvious from Google's docs!

file_paths.xml:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <files-path name="just_a_name" path=""/>
</paths>

Be careful how you specify the path. The above defaults to the root of your private internal storage.

In SharingActivity.java:

Uri contentUri = FileProvider.getUriForFile(getActivity(),
"com.mydomain.myapp.SharingActivity", myFile);
Intent shareIntent = new Intent();
shareIntent.setAction(Intent.ACTION_SEND);
shareIntent.setType("image/jpeg");
shareIntent.putExtra(Intent.EXTRA_STREAM, contentUri);
shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivity(Intent.createChooser(shareIntent, "Share with"));

In this example we are sharing a JPEG image.

Finally it is probably a good idea to assure yourself that you have saved the file properly and that you can access it with something like this:

File myFile = getActivity().getFileStreamPath("mySavedImage.jpeg");
if(myFile != null){
    Log.d(TAG, "File found, file description: "+myFile.toString());
}else{
    Log.w(TAG, "File not found!");
}

Answer 4

I want to share something that blocked us for a couple of days: the fileprovider code MUST be inserted between the application tags, not after it. It may be trivial, but it's never specified, and I thought that I could have helped someone! (thanks again to piolo94)

Answer 5

Fully working code sample how to share file from inner app folder. Tested on Android 7 and Android 5.

AndroidManifest.xml

</application>
   ....
    <provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="android.getqardio.com.gmslocationtest"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths"/>
    </provider>
</application>

xml/provider_paths

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path
        name="share"
        path="external_files"/>
</paths>

Code itself

    File imagePath = new File(getFilesDir(), "external_files");
    imagePath.mkdir();
    File imageFile = new File(imagePath.getPath(), "test.jpg");

    // Write data in your file

    Uri uri = FileProvider.getUriForFile(this, getPackageName(), imageFile);

    Intent intent = ShareCompat.IntentBuilder.from(this)
                .setStream(uri) // uri from FileProvider
                .setType("text/html")
                .getIntent()
                .setAction(Intent.ACTION_VIEW) //Change if needed
                .setDataAndType(uri, "image/*")
                .addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

   startActivity(intent);

Answer 6

In my app FileProvider works just fine, and I am able to attach internal files stored in files directory to email clients like Gmail,Yahoo etc.

In my manifest as mentioned in the Android documentation I placed:

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.package.name.fileprovider"
        android:grantUriPermissions="true"
        android:exported="false">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/filepaths" />
    </provider>

And as my files were stored in the root files directory, the filepaths.xml were as follows:

 <paths>
<files-path path="." name="name" />

Now in the code:

 File file=new File(context.getFilesDir(),"test.txt");

 Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND_MULTIPLE);

 shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT,
                                     "Test");

 shareIntent.setType("text/plain");

 shareIntent.putExtra(android.content.Intent.EXTRA_EMAIL,
                                 new String[] {"email-address you want to send the file to"});

   Uri uri = FileProvider.getUriForFile(context,"com.package.name.fileprovider",
                                                   file);

                ArrayList<Uri> uris = new ArrayList<Uri>();
                uris.add(uri);

                shareIntent .putParcelableArrayListExtra(Intent.EXTRA_STREAM,
                                                        uris);


                try {
                   context.startActivity(Intent.createChooser(shareIntent , "Email:").addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));                                                      


                }
                catch(ActivityNotFoundException e) {
                    Toast.makeText(context,
                                   "Sorry No email Application was found",
                                   Toast.LENGTH_SHORT).show();
                }
            }

This worked for me.Hope this helps :)