Develop Reference

How to send(share) csv file?

How to send(share) *csv file?
I have android app, wich create a csv file. And i want to share it: send to email, open at excel and so on.
I read tutorials:set up file sharing and sharing a file, but can not understand: is it for my option or not?
I declare a manifest:
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="com.nam1.name2.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/filepaths" />
</provider>
But what i should do next?
Can you tell me some simple code example (maybe git-repo) how to share file to another apps?
Thank you!
EDIT: I write some new code to share files (look at FileProvider example)
public class ExportActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_export);
Intent intentShareFile = new Intent(Intent.ACTION_SEND);
intentShareFile.setAction(Intent.ACTION_SEND);
File imagePath = new File(getApplicationContext().getFilesDir(), "statistics");
File newFile = new File(imagePath, "stat.csv");
CSVHelper csvHelper = new CSVHelper(SharedData.AllPlayersColl);
try {
String path=imagePath.getAbsolutePath();
csvHelper.SaveToCSV(path);
} catch (IOException e) {
e.printStackTrace();
}
Context context=getApplicationContext();
Uri contentUri = getUriForFile(context, "com.name1.name2.fileprovider", newFile);
List<ResolveInfo> resInfoList = getApplicationContext().getPackageManager()
.queryIntentActivities(intentShareFile, PackageManager.MATCH_DEFAULT_ONLY);
for (ResolveInfo resolveInfo : resInfoList) {
String packageName = resolveInfo.activityInfo.packageName;
getApplicationContext()
.grantUriPermission(packageName, contentUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
}
intentShareFile.setData(contentUri);
intentShareFile.setFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
setResult(100, intentShareFile);
startActivityForResult(intentShareFile,100);
}
}
Where CSVHelper is:
fun SaveToCSV(fileName: String?) {
if (fileName == null)
throw NullPointerException("fileName is null!")
val writer = CSVWriter(FileWriter(fileName), '\t')
// make csv file
writer.writeNext(firstLine);
}
And filepaths is:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<paths>
<files-path name="stat" path="statistics/" />
</paths>
But, i get a error:
Caused by: android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.SEND dat=content://com.name1.name2.fileprovider/stat/stat.csv flg=0x2 }
I want, that when i start an Intent a list of variants shows (at android device) : email_app,excel_app and so on. So, i want to send noname intent.

FileProvider is a helper class designed to share files as content:// URIs instead of file:// URIs which have been deprecated for some time and forbidden since API level 24.
You have declared the content provider, you need now to configure it, i.e. choose what file it can serve. This is done in the xml/filepath file that you have declared in the meta-data. You will then be able to generate shareable content URIs using FileProvider.getUriForFile().
There is a complete wrap up
Unfortunately not all application understand content:// URIs. If you need to share a file with a (very old or badly written) application which only handle file:// URIs you may still use them if you set the target level of your application to 23 or lower.

How to get orientation of image file, which was taken from FileProvider class?

Background
Targeting API 24 or above, instead of using a simple "Uri.fromFile" command, developers need to use FileProvider (or their own ContentProvider), in order to let other apps to access the app's files.
The problem
I try to open a camera app to let it save a file into my app's private storage, using this code:
final Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
final File photoFile = FileHelper.generateTempCameraFile(this);
mCameraCachedImageURI = FileProvider.getUriForFile(this, getPackageName()+ ".provider", photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCameraCachedImageURI);
takePictureIntent.setFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
startActivityForResult(takePictureIntent, REQ_CODE_PICK_IMAGE_FROM_CAMERA);
provider_paths.xml
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path name="external_files" path="."/>
</paths>
manifest file
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/provider_paths"/>
</provider>
This starts fine, as the camera app is launched, but in the returned result, I fail to get the orientation of the image file using code that previously worked fine:
#Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
super.onActivityResult(requestCode, resultCode, data);
int orientation = getOrientation(this,mCameraCachedImageURI );
...
public static int getOrientation(final Context context, final Uri photoUri) {
Cursor cursor = null;
try {
cursor = context.getContentResolver().query(photoUri,
new String[]{MediaStore.Images.ImageColumns.ORIENTATION}, null, null, null);
} catch (final Exception ignored) {
}
if (cursor == null) {
// fallback
return getOrientation(photoUri.getPath());
}
int result = 0;
if (cursor.getCount() > 0) {
cursor.moveToFirst();
result = cursor.getInt(0);
}
cursor.close();
return result;
}
public static int getOrientation(final String filePath) {
if (TextUtils.isEmpty(filePath))
return 0;
try {
final ExifInterface exifInterface = new ExifInterface(filePath);
final int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_NORMAL);
int rotate = 0;
switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_270:
rotate = 270;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
rotate = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_90:
rotate = 90;
break;
}
return rotate;
} catch (final IOException ignored) {
}
return 0;
}
This will crash, because the cursor doesn't have any columns while running this code.
Not only that, but even the fallback function (when changing the code to use it) doesn't work, as it adds an additional part to the path of the file ("external" in this case).
What I've found
It seems that the contentResolver uses the FileProvider here, instead of what was used on previous versions of Android.
Thing is, I need the ContentProvider of this URI in order to grant the camera app permission to access this file...
The question
How do I get the orientation using the above code (or even a better code), using the new FileProvider Uri ? Maybe I can force the ContentResolver to use the previously ContentProvider to get the needed column's data of the cursor?
Do I really have to create my own ContentProvider here?

A Uri is not a file. You are calling getPath() on a Uri and are treating it as if it were a file path. That only works if the scheme in the Uri is file. In your case, it is not.
You already have a File object pointing to the file. It is called photoFile. Hold onto that in a field of your activity, and save it in the saved instance state Bundle (as your process might get terminated while the camera app is in the foreground). Then, use photoFile. Don't use the built-in ExifInterface though, as it has security flaws.
How do I get the orientation using the above code (or even a better code), using the new FileProvider Uri ?
You don't. Use photoFile.
Maybe I can force the ContentResolver to use the previously ContentProvider to get the needed column's data of the cursor?
I have no idea why you would expect the getOrientation() that takes a Uri to work. You are querying the MediaStore for data about a Uri that does not come from the MediaStore.
Do I really have to create my own ContentProvider here?
No, because FileProvider is not your problem. You would have the same flawed getOrientation() methods with your own ContentProvider.

Trying to takePersistableUriPermission() fails for custom DocumentsProvider via ACTION_OPEN_DOCUMENT

I am trying to write a custom DocumentsProvider that allows other apps to take persistable permissions to the Uris it provides
I have a DocumentsProvider that I declare in my AndroidManufest.xml as follows
<provider
android:name="com.cgogolin.myapp.MyContentProvider"
android:authorities="com.cgogolin.myapp.MyContentProvider"
android:grantUriPermissions="true"
android:exported="true"
android:permission="android.permission.MANAGE_DOCUMENTS"
android:enabled="#bool/atLeastKitKat">
<intent-filter>
<action android:name="android.content.action.DOCUMENTS_PROVIDER" />
</intent-filter>
</provider>
and my app has the MANAGE_DOCUMENTS permission set
<uses-permission android:name="android.permission.MANAGE_DOCUMENTS" />
(apparently this is not necessary but adding/removing it also doesn't matter).
I can then see my provider when I open the ACTION_OPEN_DOCUMENT picker UI with
Intent openDocumentIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
openDocumentIntent.addCategory(Intent.CATEGORY_OPENABLE);
openDocumentIntent.setType("application/pdf");
openDocumentIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION|Intent.FLAG_GRANT_WRITE_URI_PERMISSION|Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION);
startActivityForResult(openDocumentIntent, EDIT_REQUEST);
and, after picking a file from my provider there, in the onActivityResult() method of my App I can then successfully open the file provided by my DocumentsProvider via the Uri I get from intent.getData().
However, trying to persist read or write permissions with
getContentResolver().takePersistableUriPermission(uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
or
getContentResolver().takePersistableUriPermission(uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
always fails with an exception like
No permission grant found for UID 10210 and Uri content://com.cgogolin.myapp.MyContentProvider/document/tshjhczf.pdf
If I pick a file from the google drive or downloads provider in the picker UI taking permissions in this way works. So I think the problem is in my provider.
Why is there no permission grant created despite me specifying android:grantUriPermissions="true"?
How can I convince Android to create such a permission grant for me?
After all I don't think I can do it myself, as I cannot know the UID of the process that opened the picker UI, or at least not that I knew how.

EDIT:
My previous answer wasn't good. You are suppose to use "android.permission.MANAGE_DOCUMENTS" for security reasons.
Only System UI picker will be able to list your documents.
But you don't need this permission in the manifest of the application that opens documents.
Actually you should not to be able to gain this permission as it is system permission.
I've just tested it and call to takePersistableUriPermission form onActivityResult was successful.
I used DocumentProvider with mock data (one root, 3 txt documents).
If it still doesn't work for you there could be some issue with your document provider.
EDIT2:
Sample code
package com.example.test;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.os.CancellationSignal;
import android.os.ParcelFileDescriptor;
import android.provider.DocumentsProvider;
import java.io.FileNotFoundException;
public class MyContentProvider extends DocumentsProvider {
private final static String[] rootColumns = new String[]{
"_id", "root_id", "title", "icon"
};
private final static String[] docColumns = new String[]{
"_id", "document_id", "_display_name", "mime_type", "icon"
};
MatrixCursor matrixCursor;
MatrixCursor matrixRootCursor;
#Override
public boolean onCreate() {
matrixRootCursor = new MatrixCursor(rootColumns);
matrixRootCursor.addRow(new Object[]{1, 1, "TEST", R.mipmap.ic_launcher});
matrixCursor = new MatrixCursor(docColumns);
matrixCursor.addRow(new Object[]{1, 1, "a.txt", "text/plain", R.mipmap.ic_launcher});
matrixCursor.addRow(new Object[]{2, 2, "b.txt", "text/plain", R.mipmap.ic_launcher});
matrixCursor.addRow(new Object[]{3, 3, "c.txt", "text/plain", R.mipmap.ic_launcher});
return true;
}
#Override
public Cursor queryRoots(String[] projection) throws FileNotFoundException {
return matrixRootCursor;
}
#Override
public Cursor queryDocument(String documentId, String[] projection)
throws FileNotFoundException {
return matrixCursor;
}
#Override
public Cursor queryChildDocuments(String parentDocumentId, String[] projection,
String sortOrder)
throws FileNotFoundException {
return matrixCursor;
}
#Override
public ParcelFileDescriptor openDocument(String documentId, String mode,
CancellationSignal signal)
throws FileNotFoundException {
int id;
try {
id = Integer.valueOf(documentId);
} catch (NumberFormatException e) {
throw new FileNotFoundException("Incorrect document ID " + documentId);
}
String filename = "/sdcard/";
switch (id) {
case 1:
filename += "a.txt";
break;
case 2:
filename += "b.txt";
break;
case 3:
filename += "c.txt";
break;
default:
throw new FileNotFoundException("Unknown document ID " + documentId);
}
return ParcelFileDescriptor.open(new File(filename),
ParcelFileDescriptor.MODE_READ_WRITE);
}
}
Note:
You can use constants from DocumentsContract.Document and DocumentsContract.Root.
I'm not sure whether "_id" is required.
EDIT3:
Updated sample code to open documents from /sdcard.
Added read/write external storage permissions.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest
package="com.example.test"
xmlns:android="http://schemas.android.com/apk/res/android">
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name">
<provider
android:name="com.example.test.MyContentProvider"
android:authorities="com.example.test.document"
android:enabled="true"
android:exported="#bool/atLeastKitKat"
android:grantUriPermissions="true"
android:permission="android.permission.MANAGE_DOCUMENTS">
<intent-filter>
<action android:name="android.content.action.DOCUMENTS_PROVIDER"/>
</intent-filter>
</provider>
</application>
</manifest>
Client app
New project with an empty activity, no permission added.
Open document
Intent openDocumentIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
openDocumentIntent.addCategory(Intent.CATEGORY_OPENABLE);
openDocumentIntent.setType("text/plain");
openDocumentIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION
| Intent.FLAG_GRANT_WRITE_URI_PERMISSION
| Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION);
startActivityForResult(openDocumentIntent, 1);
onActivityResult
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case 1: // TODO: Use constant
if (resultCode == RESULT_OK) {
if (data == null) return; // TODO: Show error
Uri uri = data.getData();
if (uri == null) return; // TODO: Show error
getContentResolver().takePersistableUriPermission(uri,
Intent.FLAG_GRANT_READ_URI_PERMISSION);
InputStream is = null;
try {
is = getContentResolver().openInputStream(uri);
// Just for quick sample (I know what I will read)
byte[] buffer = new byte[1024];
int read = is.read(buffer);
String text = new String(buffer, 0, read);
((TextView) findViewById(R.id.text)).setText(text);
} catch (IOException e) {
e.printStackTrace();
} finally {
if (is != null) try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
break;
}
}

When working with SAF, the expected behavior on API 19-25 is that a SecurityException is thrown for URIs from your own DocumentProvider.
This has changed on API 26 and above which now allows persistable URI permission for URIs even from your own process (no official docs but an observation through testing)
But even if you get a SecurityException while trying to take persistable URI permission you'd still always have access to URIs exposed from your own DocumentsProvider.
Thus it'd be a good idea to catch and ignore the SecurityException when the content authority is from your own process.
Note: If your app contains a DocumentsProvider and also persists URIs returned from ACTION_OPEN_DOCUMENT, ACTION_OPEN_DOCUMENT_TREE, or ACTION_CREATE_DOCUMENT, be aware that you won’t be able to persist access to your own URIs via takePersistableUriPermission() — despite it failing with a SecurityException, you’ll always have access to URIs from your own app. You can add the boolean EXTRA_EXCLUDE_SELF to your Intents if you want to hide your own DocumentsProvider(s) on API 23+ devices for any of these actions.
Here's a note from official Android Developers blog that confirms this behavior - https://medium.com/androiddevelopers/building-a-documentsprovider-f7f2fb38e86a

Create and Share a File from Internal Storage

My goal is to create a XML file on internal storage and then send it through the share Intent.
I'm able to create a XML file using this code
FileOutputStream outputStream = context.openFileOutput(fileName, Context.MODE_WORLD_READABLE);
PrintStream printStream = new PrintStream(outputStream);
String xml = this.writeXml(); // get XML here
printStream.println(xml);
printStream.close();
I'm stuck trying to retrieve a Uri to the output file in order to share it. I first tried to access the file by converting the file to a Uri
File outFile = context.getFileStreamPath(fileName);
return Uri.fromFile(outFile);
This returns file:///data/data/com.my.package/files/myfile.xml but I cannot appear to attach this to an email, upload, etc.
If I manually check the file length, it's proper and shows there is a reasonable file size.
Next I created a content provider and tried to reference the file and it isn't a valid handle to the file. The ContentProvider doesn't ever seem to be called a any point.
Uri uri = Uri.parse("content://" + CachedFileProvider.AUTHORITY + "/" + fileName);
return uri;
This returns content://com.my.package.provider/myfile.xml but I check the file and it's zero length.
How do I access files properly? Do I need to create the file with the content provider? If so, how?
Update
Here is the code I'm using to share. If I select Gmail, it does show as an attachment but when I send it gives an error Couldn't show attachment and the email that arrives has no attachment.
public void onClick(View view) {
Log.d(TAG, "onClick " + view.getId());
switch (view.getId()) {
case R.id.share_cancel:
setResult(RESULT_CANCELED, getIntent());
finish();
break;
case R.id.share_share:
MyXml xml = new MyXml();
Uri uri;
try {
uri = xml.writeXmlToFile(getApplicationContext(), "myfile.xml");
//uri is "file:///data/data/com.my.package/files/myfile.xml"
Log.d(TAG, "Share URI: " + uri.toString() + " path: " + uri.getPath());
File f = new File(uri.getPath());
Log.d(TAG, "File length: " + f.length());
// shows a valid file size
Intent shareIntent = new Intent();
shareIntent.setAction(Intent.ACTION_SEND);
shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
shareIntent.setType("text/plain");
startActivity(Intent.createChooser(shareIntent, "Share"));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
break;
}
}
I noticed that there is an Exception thrown here from inside createChooser(...), but I can't figure out why it's thrown.
E/ActivityThread(572): Activity
com.android.internal.app.ChooserActivity has leaked IntentReceiver
com.android.internal.app.ResolverActivity$1#4148d658 that was
originally registered here. Are you missing a call to
unregisterReceiver()?
I've researched this error and can't find anything obvious. Both of these links suggest that I need to unregister a receiver.
ChooserActivity has leaked IntentReceiver
Why does Intent.createChooser() need a BroadcastReceiver and how to implement?
I have a receiver setup, but it's for an AlarmManager that is set elsewhere and doesn't require the app to register / unregister.
Code for openFile(...)
In case it's needed, here is the content provider I've created.
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
String fileLocation = getContext().getCacheDir() + "/" + uri.getLastPathSegment();
ParcelFileDescriptor pfd = ParcelFileDescriptor.open(new File(fileLocation), ParcelFileDescriptor.MODE_READ_ONLY);
return pfd;
}

It is possible to expose a file stored in your apps private directory via a ContentProvider. Here is some example code I made showing how to create a content provider that can do this.
Manifest
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.providertest"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="11" android:targetSdkVersion="15" />
<application android:label="#string/app_name"
android:icon="#drawable/ic_launcher"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<provider
android:name="MyProvider"
android:authorities="com.example.prov"
android:exported="true"
/>
</application>
</manifest>
In your ContentProvider override openFile to return the ParcelFileDescriptor
#Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
File cacheDir = getContext().getCacheDir();
File privateFile = new File(cacheDir, "file.xml");
return ParcelFileDescriptor.open(privateFile, ParcelFileDescriptor.MODE_READ_ONLY);
}
Make sure you have copied your xml file to the cache directory
private void copyFileToInternal() {
try {
InputStream is = getAssets().open("file.xml");
File cacheDir = getCacheDir();
File outFile = new File(cacheDir, "file.xml");
OutputStream os = new FileOutputStream(outFile.getAbsolutePath());
byte[] buff = new byte[1024];
int len;
while ((len = is.read(buff)) > 0) {
os.write(buff, 0, len);
}
os.flush();
os.close();
is.close();
} catch (IOException e) {
e.printStackTrace(); // TODO: should close streams properly here
}
}
Now any other apps should be able to get an InputStream for your private file by using the content uri (content://com.example.prov/myfile.xml)
For a simple test, call the content provider from a seperate app similar to the following
private class MyTask extends AsyncTask<String, Integer, String> {
#Override
protected String doInBackground(String... params) {
Uri uri = Uri.parse("content://com.example.prov/myfile.xml");
InputStream is = null;
StringBuilder result = new StringBuilder();
try {
is = getApplicationContext().getContentResolver().openInputStream(uri);
BufferedReader r = new BufferedReader(new InputStreamReader(is));
String line;
while ((line = r.readLine()) != null) {
result.append(line);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try { if (is != null) is.close(); } catch (IOException e) { }
}
return result.toString();
}
#Override
protected void onPostExecute(String result) {
Toast.makeText(CallerActivity.this, result, Toast.LENGTH_LONG).show();
super.onPostExecute(result);
}
}

So Rob's answer is correct I assume but I did it a bit differently. As far as I understand, with the setting in in provider:
android:exported="true"
you are giving public access to all your files?! Anyway, a way to give only access to some files is to define file path permissions in the following way:
<provider
android:authorities="com.your.app.package"
android:name="android.support.v4.content.FileProvider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths" />
</provider>
and then in your XML directory you define file_paths.xml file as follows:
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<files-path path="/" name="allfiles" />
<files-path path="tmp/" name="tmp" />
</paths>
now, the "allfiles" gives the same kind of public permission I guess as the option android:exported="true" but you don't really want that I guess so to define a subdirectory is the next line. Then all you have to do is store the files you want to share, there in that dir.
Next what you have to do is, as also Rob says, obtain a URI for this file. This is how I did it:
Uri contentUri = FileProvider.getUriForFile(context, "com.your.app.package", sharedFile);
Then, when I have this URI, I had to attach to it permissions for other app to use it. I was using or sending this file URI to camera app. Anyway this is the way how I got the other app package info and granted permissions to the URI:
PackageManager packageManager = getPackageManager();
List<ResolveInfo> list = packageManager.queryIntentActivities(cameraIntent, PackageManager.MATCH_DEFAULT_ONLY);
if (list.size() < 1) {
return;
}
String packageName = list.get(0).activityInfo.packageName;
grantUriPermission(packageName, sharedFileUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
ClipData clipData = ClipData.newRawUri("CAMFILE", sharedFileUri);
cameraIntent.setClipData(clipData);
cameraIntent.setFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
cameraIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivityForResult(cameraIntent, GET_FROM_CAMERA);
I left the code for camera as I did not want to take some other example I did not work on. But this way you see that you can attach permissions to URI itself.
The camera's thing is that I can set it via ClipData and then additionally set permissions. I guess in your case you only need FLAG_GRANT_READ_URI_PERMISSION as you are attaching a file to an email.
Here is the link to help on FileProvider as I based all of my post on the info I found there. Had some trouble finding a package info for camera app though.
Hope it helps.

None of the above answers helped. My problem was the point of passing intent extras but I'll walk you through all the steps to share a file.
Step 1: Create a Content Provider
This will make the file accessible to whichever app you want to share with.
Paste the following in the Manifest.xml file inside the <application></applicatio> tags
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="{YOUR_PACKAGE_NAME}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/provider_paths" />
</provider>
Step 2: Define paths accessible by the content provider
Do this by creating a file called provider_paths.xml (or a name of your choice) under res/xml. Put the following code in the file
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path
name="external"
path="." />
<external-files-path
name="external_files"
path="." />
<cache-path
name="cache"
path="." />
<external-cache-path
name="external_cache"
path="." />
<files-path
name="files"
path="." />
</paths>
Step 3: Create the Intent to share the file
Intent intentShareFile = new Intent(Intent.ACTION_SEND);
Uri uri = FileProvider.getUriForFile(getApplicationContext(), getPackageName() + ".fileprovider", fileToShare);
intentShareFile.setDataAndType(uri, URLConnection.guessContentTypeFromName(fileToShare.getName()));
//Allow sharing apps to read the file Uri
intentShareFile.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
//Pass the file Uri instead of the path
intentShareFile.putExtra(Intent.EXTRA_STREAM,
uri);
startActivity(Intent.createChooser(intentShareFile, "Share File"));

If you need to permission other apps to see your app's private files (for Share, or otherwise) you might be able to save some time and just use v4 compat library's FileProvider

This is what i'm using:
I combined some answers and used the current AndroidX Doku:
Sharing files Android Development
Basic Process: You change the manifest to make it possible for other apps to access your local files. the filepath's that are allowed to be accessed from outside are found in the res/xml/filepaths.xml. When sharing you create an intent to share and set a Flag that temporarily allowed the other app to access your local files. Android documentation claims this is the secure way to share files
Step1: Add FileProvider to Manifest
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="com.YOUR.APP.PACKAGE.fileprovider"
android:grantUriPermissions="true"
android:exported="false">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/filepaths" />
</provider>
Step2: Add filepaths.xml to res/xml (if XML folder does not exists just create it yourself)
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<files-path path="share/" name="share" />
</paths>
Step3: Use a function like this to start a file share. this function moves the file to the predefined share folder and creates a Url to it. the ShareDir is the File pointing to the files/share/ directory. the copy_File function copies the given file to the share directory in order to be accessible from the outside.
The function also makes it possible to Send the File as email with given header and body. if not needed just set it to empty strings
public void ShareFiles(Activity activity, List<File> files, String header, String body) {
ArrayList<Uri> uriList = new ArrayList<>();
if(files != null) {
for (File f : files) {
if (f.exists()) {
File file_in_share = copy_File(f, ShareDir);
if(file_in_share == null)
continue;
// Use the FileProvider to get a content URI
try {
Uri fileUri = FileProvider.getUriForFile(
activity,
"com.YOUR.APP.PACKAGE.fileprovider",
file_in_share);
uriList.add(fileUri);
} catch (IllegalArgumentException e) {
Log.e("File Selector",
"The selected file can't be shared: " + f.toString());
}
}
}
}
if(uriList.size() == 0)
{
Log.w("StorageModule", "ShareFiles: no files to share");
return;
}
Intent intent = new Intent(Intent.ACTION_SEND_MULTIPLE);
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.setType("text/html");
intent.putExtra(Intent.EXTRA_SUBJECT, header);
intent.putExtra(Intent.EXTRA_TEXT, body);
intent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uriList);
activity.startActivity(Intent.createChooser(intent, "Share Files"));
}

Convert file uri to content uri

i want to choose a file (via file chooser) from astro manager (in my case a *.pdf or *.doc) but the uri contains only the file path ("sdcard/my_folder/test.pdf"). For my application i need the content path like that from image chooser (content://media/external/images/media/2
). Is there any way to convert a "file:///" to "content://" uri?
Or has anybody an other idea how to solve that problem?
best regards
UPDATE: the main problem is that after i choose my file with filechooser valuecallback.onReceiveValue(uri) method adds a "/" behind the path. So i get an uri like this: "sdcard/my_folder/test.pdf/" and my application thinks pdf is a folder. When i use content uri from image chooser it works.

Like #CommmonsWare said, there is no easy way to convert any type of files into content:// .
But here is how I convert an image File into content://
public static Uri getImageContentUri(Context context, File imageFile) {
String filePath = imageFile.getAbsolutePath();
Cursor cursor = context.getContentResolver().query(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
new String[] { MediaStore.Images.Media._ID },
MediaStore.Images.Media.DATA + "=? ",
new String[] { filePath }, null);
if (cursor != null && cursor.moveToFirst()) {
int id = cursor.getInt(cursor
.getColumnIndex(MediaStore.MediaColumns._ID));
Uri baseUri = Uri.parse("content://media/external/images/media");
return Uri.withAppendedPath(baseUri, "" + id);
} else {
if (imageFile.exists()) {
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.DATA, filePath);
return context.getContentResolver().insert(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
} else {
return null;
}
}
}

Here is a simpler way to consider, which may be suitable for you.
I use it for sharing downloaded images on google plus from my android app:
/**
* Converts a file to a content uri, by inserting it into the media store.
* Requires this permission: <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
*/
protected static Uri convertFileToContentUri(Context context, File file) throws Exception {
//Uri localImageUri = Uri.fromFile(localImageFile); // Not suitable as it's not a content Uri
ContentResolver cr = context.getContentResolver();
String imagePath = file.getAbsolutePath();
String imageName = null;
String imageDescription = null;
String uriString = MediaStore.Images.Media.insertImage(cr, imagePath, imageName, imageDescription);
return Uri.parse(uriString);
}

One simple way to achieve this could be by using MediaScannerConnection
File file = new File("pathname");
MediaScannerConnection.scanFile(getContext(), new String[]{file.getAbsolutePath()}, null /*mimeTypes*/, new MediaScannerConnection.OnScanCompletedListener() {
#Override
public void onScanCompleted(String s, Uri uri) {
// uri is in format content://...
}
});

This works for me and what I use in my Share Folder app:
Create a folder called xml under resources
Add a file_paths.xml to it, with following line in it:
<files-path name="internal" path="/"/>
Add a File provider authority in the manifest, as:
<provider android:name="android.support.v4.content.FileProvider"
android:authorities="com.dasmic.filebrowser.FileProvider"
android:windowSoftInputMode="stateHidden|adjustResize"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths" />
</provider>
4.Transfer file to a different intent with 'content://' as follows:
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); //Required for Android 8+
Uri data = FileProvider.getUriForFile(this, "com.dasmic.filebrowser.FileProvider", file);
intent.setDataAndType(data, type);
startActivity(intent);

you can achieve it my using FileProvider
step 1:
create a java file and extends it with FileProvider
public class MyFileProvider extends FileProvider {
}
step 2:
create an xml resource file in res/xml/ directory and copy this code in it
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="external_files" path="."/>
</paths>
step 3:
in your manifest file, under <Application> tag add this code
<provider
android:name="MyFileProvider" <!-- java file created above -->
android:authorities="${applicationId}.MyFileProvider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/provider_paths"/> <!-- xml file created above -->
</provider>
Step 4:
use this code to get Uri in content:// format
Uri uri = FileProvider.getUriForFile(CameraActivity.this, "your.package.name.MyFileProvider", file /* file whose Uri is required */);
Note:
you may need to add read permission
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

try this:
Uri myUri = Uri.fromFile(new File("/sdcard/cats.jpg"));
Or with:
Uri myUri = Uri.parse(new File("/sdcard/cats.jpg").toString());