android share images from assets folder

android share images from assets folder - android

I'm trying to share an image from my assets folder. My code is:
Intent share = new Intent(Intent.ACTION_SEND);
share.setType("image/jpg");
share.putExtra(Intent.EXTRA_STREAM, Uri.parse("file:///assets/myImage.jpg"));
startActivity(Intent.createChooser(share, "Share This Image"));
but it doesn't work. Do you have any ideas?

It is possible to share files (images including) from the assets folder through a custom ContentProvider
You need to extend ContentProvider, register it in your manifest and implement the openAssetFile method. You can then assess the assets via Uris
#Override
public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException {
AssetManager am = getContext().getAssets();
String file_name = uri.getLastPathSegment();
if(file_name == null)
throw new FileNotFoundException();
AssetFileDescriptor afd = null;
try {
afd = am.openFd(file_name);
} catch (IOException e) {
e.printStackTrace();
}
return afd;
}

Complementing what #intrepidis answered:
You will need override methods like example class above:
package com.android.example;
import android.content.ContentProvider;
import android.net.Uri;
import android.content.res.AssetFileDescriptor;
import android.content.res.AssetManager;
import java.io.FileNotFoundException;
import android.content.ContentValues;
import android.database.Cursor;
import java.io.IOException;
import android.os.CancellationSignal;
public class AssetsProvider extends ContentProvider
{
#Override
public AssetFileDescriptor openAssetFile( Uri uri, String mode ) throws FileNotFoundException
{
Log.v( TAG, "AssetsGetter: Open asset file" );
AssetManager am = getContext( ).getAssets( );
String file_name = uri.getLastPathSegment( );
if( file_name == null )
throw new FileNotFoundException( );
AssetFileDescriptor afd = null;
try
{
afd = am.openFd( file_name );
}
catch(IOException e)
{
e.printStackTrace( );
}
return afd;//super.openAssetFile(uri, mode);
}
#Override
public String getType( Uri p1 )
{
// TODO: Implement this method
return null;
}
#Override
public int delete( Uri p1, String p2, String[] p3 )
{
// TODO: Implement this method
return 0;
}
#Override
public Cursor query( Uri p1, String[] p2, String p3, String[] p4, String p5 )
{
// TODO: Implement this method
return null;
}
#Override
public Cursor query( Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder, CancellationSignal cancellationSignal )
{
// TODO: Implement this method
return super.query( uri, projection, selection, selectionArgs, sortOrder, cancellationSignal );
}
#Override
public Uri insert( Uri p1, ContentValues p2 )
{
// TODO: Implement this method
return null;
}
#Override
public boolean onCreate( )
{
// TODO: Implement this method
return false;
}
#Override
public int update( Uri p1, ContentValues p2, String p3, String[] p4 )
{
// TODO: Implement this method
return 0;
}
}
I needed to override two times the query method.
And add these lines above tag in your androidmanifest.xml:
<provider
android:name="com.android.example.AssetsProvider"
android:authorities="com.android.example"
android:grantUriPermissions="true"
android:exported="true" />
And with this, all work like a charm :D

This blog explains it all:
http://nowherenearithaca.blogspot.co.uk/2012/03/too-easy-using-contentprovider-to-send.html
Basically, this goes in the manifest:
<provider android:name="yourclass.that.extendsContentProvider" android:authorities="com.yourdomain.whatever"/>
The content provider class has this:
#Override
public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException {
AssetManager am = getContext().getAssets();
String file_name = uri.getLastPathSegment();
if(file_name == null)
throw new FileNotFoundException();
AssetFileDescriptor afd = null;
try {
afd = am.openFd(file_name);
} catch (IOException e) {
e.printStackTrace();
}
return afd;//super.openAssetFile(uri, mode);
}
And the calling code does this:
Uri theUri = Uri.parse("content://com.yourdomain.whatever/someFileInAssetsFolder");
Intent theIntent = new Intent(Intent.ACTION_SEND);
theIntent.setType("image/*");
theIntent.putExtra(Intent.EXTRA_STREAM,theUri);
theIntent.putExtra(android.content.Intent.EXTRA_SUBJECT,"Subject for message");
theIntent.putExtra(android.content.Intent.EXTRA_TEXT, "Body for message");
startActivity(theIntent);

Many apps require you to provide name and size of the image. So here is an improved code (using Google's FileProvider code as an example):
public class AssetsProvider extends ContentProvider {
private final static String LOG_TAG = AssetsProvider.class.getName();
private static final String[] COLUMNS = {
OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE };
#Override
public boolean onCreate() {
return true;
}
#Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
/**
* Source: {#link FileProvider#query(Uri, String[], String, String[], String)} .
*/
if (projection == null) {
projection = COLUMNS;
}
final AssetManager am = getContext().getAssets();
final String path = getRelativePath(uri);
long fileSize = 0;
try {
final AssetFileDescriptor afd = am.openFd(path);
fileSize = afd.getLength();
afd.close();
} catch(IOException e) {
Log.e(LOG_TAG, "Can't open asset file", e);
}
final String[] cols = new String[projection.length];
final Object[] values = new Object[projection.length];
int i = 0;
for (String col : projection) {
if (OpenableColumns.DISPLAY_NAME.equals(col)) {
cols[i] = OpenableColumns.DISPLAY_NAME;
values[i++] = uri.getLastPathSegment();
} else if (OpenableColumns.SIZE.equals(col)) {
cols[i] = OpenableColumns.SIZE;
values[i++] = fileSize;
}
}
final MatrixCursor cursor = new MatrixCursor(cols, 1);
cursor.addRow(values);
return cursor;
}
#Override
public String getType(Uri uri) {
/**
* Source: {#link FileProvider#getType(Uri)} .
*/
final String file_name = uri.getLastPathSegment();
final int lastDot = file_name.lastIndexOf('.');
if (lastDot >= 0) {
final String extension = file_name.substring(lastDot + 1);
final String mime = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
if (mime != null) {
return mime;
}
}
return "application/octet-stream";
}
#Override
public Uri insert(Uri uri, ContentValues values) {
return null;
}
#Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return 0;
}
#Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
return 0;
}
#Override
public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException {
final AssetManager am = getContext().getAssets();
final String path = getRelativePath(uri);
if(path == null) {
throw new FileNotFoundException();
}
AssetFileDescriptor afd = null;
try {
afd = am.openFd(path);
} catch(IOException e) {
Log.e(LOG_TAG, "Can't open asset file", e);
}
return afd;
}
private String getRelativePath(Uri uri) {
String path = uri.getPath();
if (path.charAt(0) == '/') {
path = path.substring(1);
}
return path;
}
}

Since none of the other answers here worked for me (in 2019) I made a workaround by copying the asset to the app's internal file directory and then sharing this file.
In my case, I needed to share a pdf file from the assets folder.
In the AndroidManifest.xml add a file provider (no need to use a custom one):
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/filepaths" />
</provider>
Create a filepaths.xml file in res/xml/
<?xml version="1.0" encoding="utf-8"?>
<paths>
<files-path
name="root"
path="/" />
</paths>
Of course you should use a subdirectory here if you manage other files in your app directory.
Now in the class where you want to trigger the share intent.
1. Create an empty file in the files directory
private fun createFileInFilesDir(filename: String): File {
val file = File(filesDir.path + "/" + filename)
if (file.exists()) {
if (!file.delete()) {
throw IOException()
}
}
if (!file.createNewFile()) {
throw IOException()
}
return file
}
2. Copy the content of the asset to the file
private fun copyAssetToFile(assetName: String, file: File) {
val buffer = ByteArray(1024)
val inputStream = assets.open(assetName)
val outputStream: OutputStream = FileOutputStream(file)
while (inputStream.read(buffer) > 0) {
outputStream.write(buffer)
}
}
3. Create a share intent for the file
private fun createIntentForFile(file: File, intentAction: String): Intent {
val uri = FileProvider.getUriForFile(this, applicationContext.packageName + ".provider", file)
val intent = Intent(intentAction)
intent.flags = Intent.FLAG_GRANT_READ_URI_PERMISSION
intent.setDataAndType(uri, "application/pdf")
return intent
}
4. Execute 1-3 and fire the intent
private fun sharePdfAsset(assetName: String, intentAction: String) {
try {
val file = createFileInFilesDir(assetName)
copyAssetToFile(assetName, file)
val intent = createIntentForFile(file, intentAction)
startActivity(Intent.createChooser(intent, null))
} catch (e: IOException) {
e.printStackTrace()
AlertDialog.Builder(this)
.setTitle(R.string.error)
.setMessage(R.string.share_error)
.show()
}
}
5. Call the function
sharePdfAsset("your_pdf_asset.pdf", Intent.ACTION_SEND)
If you want to delete the file after sharing it, you probably could use startActivityForResult() and delete it afterwards. By changing the intentAction you can also use this process for an "open with..." action by using Intent.ACTION_VIEW.
For assets, filesDir, ... you need to be in an Activity or have a Context of course.

AFAIK, there's no way to share an image from the assets folder. But it's possible to share resources from the res folder.

To share from assets folder I can only recommend the cwac-provider library (StreamProvider).
Among avoiding to develop your own content provider, it adds some support for capricious legacy apps (check USE_LEGACY_CURSOR_WRAPPER).

Related

Creating file from Uri

I'm trying to upload a image to php, for that I need to send a File to the server. So I am trying to create a file from the data parameter.
But I got this error Cannot resolve constructor File
Here's my code:
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
// Get the url from data
Uri selectedImageUri = data.getData();
if (null != selectedImageUri) {
// File
File imageFilePath = new File(selectedImageUri);

The appropriate way is to getContentResolver().openInputStream(uri_of_your_file); and using a FileOutputStream to your desired path and then use that file.
As from Commonsware answer
You can use ContentResolver and openInputStream() to get an
InputStream on the content represented by the Uri. You can create a
FileOutputStream on some file that you control. And, you can use Java
I/O to copy from the InputStream to the OutputStream, making your own
copy of the content in a file that you control.
Sample code for doing that,
InputStream in = getContentResolver().openInputStream("your_uri_here");
OutputStream out = new FileOutputStream(new File("your_file_here"));
byte[] buf = new byte[1024];
int len;
while((len=in.read(buf))>0){
out.write(buf,0,len);
}
out.close();
in.close();

#GeekDroid's answer is correct, but I thought I would provide more info to help clarify.
I've also created a library that will return the file path from an Uri when selecting a File from MediaStore.
I've created a class that will copy/create a new file inside your application's directory. This is done on the background thread, as it should be done.
I have also created a callback interface to get the "status" and display a ProgressBar
Here is the interface(You can change the name and callbacks to whatever):
interface CallBackTask {
void onCopyPreExecute();
void onCopyProgressUpdate(int progress);
void onCopyPostExecute(String path, boolean wasSuccessful, String reason);
}
Here is the class to copy the file:
public class CopyFileAsyncTask extends AsyncTask<Uri, Integer, String> {
private Uri mUri;
private CallBackTask callback;
private WeakReference<Context> mContext;
private String pathPlusName;
private File folder;
private Cursor returnCursor;
private InputStream is = null;
private String errorReason = "";
DownloadAsyncTask(Uri uri, Context context, CallBackTask callback) {
this.mUri = uri;
mContext = new WeakReference<>(context);
this.callback = callback;
}
#Override
protected void onPreExecute() {
callback.onCopyPreExecute();
Context context = mContext.get();
if (context != null) {
folder = context.getExternalFilesDir("Temp");
returnCursor = context.getContentResolver().query(mUri, null, null, null, null);
try {
is = context.getContentResolver().openInputStream(mUri);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
int post = values[0];
callback.onCopyProgressUpdate(post);
}
#Override
protected String doInBackground(Uri... params) {
File file = null;
int size = -1;
try {
try {
if (returnCursor != null && returnCursor.moveToFirst()){
if (mUri.getScheme() != null)
if (mUri.getScheme().equals("content")) {
int sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE);
size = (int) returnCursor.getLong(sizeIndex);
}else if (mUri.getScheme().equals("file")) {
File ff = new File(mUri.getPath());
size = (int) ff.length();
}
}
}
finally {
if (returnCursor != null)
returnCursor.close();
}
pathPlusName = folder + "/" + getFileName(mUri, mContext.get());
file = new File(folder + "/" + getFileName(mUri, mContext.get()));
BufferedInputStream bis = new BufferedInputStream(is);
FileOutputStream fos = new FileOutputStream(file);
byte[] data = new byte[1024];
long total = 0;
int count;
while ((count = bis.read(data)) != -1) {
if (!isCancelled()) {
total += count;
if (size != -1) {
publishProgress((int) ((total * 100) / size));
}
fos.write(data, 0, count);
}
}
fos.flush();
fos.close();
} catch (IOException e) {
errorReason = e.getMessage();
}
return file.getAbsolutePath();
}
private String getFileName(Uri uri, Context context) {
String result = null;
if (uri.getScheme() != null) {
if (uri.getScheme().equals("content")) {
Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
if (cursor != null && cursor.moveToFirst()) {
result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
}
if (cursor != null) {
cursor.close();
}
}
}
if (result == null) {
result = uri.getPath();
assert result != null;
int cut = result.lastIndexOf('/');
if (cut != -1) {
result = result.substring(cut + 1);
}
}
return result;
}
protected void onPostExecute(String result) {
if(result == null){
callback.onCopyPostExecute(pathPlusName, false, errorReason);
}else {
callback.onCopyPostExecute(pathPlusName, true, "");
}
}
}
In your Activity you should do the following:
import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ContextThemeWrapper;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
public class ExampleActivity extends AppCompatActivity implements CallBackTask{
Button someBtn;
Uri someUri = .... //This is just an example, you should provide your own Uri
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_example);
someBtn = findViewById(R.id.someBtn);
someBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
CopyFileAsyncTask asyntask = new CopyFileAsyncTask(someUri, ExampleActivity.this, ExampleActivity.this);
asyntask.execute();
}
});
}
ProgressBar mProgressBar;
TextView percentText;
private AlertDialog mdialog;
#Override
public void onCopyPreExecute() {
final AlertDialog.Builder mPro = new AlertDialog.Builder(new ContextThemeWrapper(this, R.style.myDialog));
#SuppressLint("InflateParams") final View mPView = LayoutInflater.from(this).inflate(R.layout.dailog_layout, null);
percentText = mPView.findViewById(R.id.percentText);
mProgressBar = mPView.findViewById(R.id.mProgressBar);
mProgressBar.setMax(100);
mPro.setView(mPView);
mdialog = mPro.create();
mdialog.show();
}
#Override
public void onCopyProgressUpdate(int progress) {
String progressPlusPercent = progress + "%";
percentText.setText(progressPlusPercent);
mProgressBar.setProgress(progress);
}
#Override
public void onCopyPostExecute(String path, boolean wasSuccessful, String reason) {
if (mdialog != null && mdialog.isShowing()) {
mdialog.cancel();
}
if (wasSuccessful){
Toast.makeText(this, "File was created at - "+path, Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(this, "Error - "+reason, Toast.LENGTH_SHORT).show();
}
}
}
You can cancel the copying of the file at any time, by calling:
if (asyntask!=null){
asyntask.cancel(true);
}
If you want to implement it exactly as I did and display a ProgressBar while the file is being copied, then here is the layout and style of my dialog:
R.style.myDialog:
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="myDialog" parent="Theme.AppCompat.Dialog.Alert">
<item name="android:windowNoTitle">true</item>
<item name="android:background">#fff</item>
<item name="android:windowBackground">#null</item>
<item name="android:windowFrame">#null</item>
<item name="android:windowIsFloating">true</item>
<item name="android:backgroundDimEnabled">true</item>
</style>
</resources>
R.layout.dailog_layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:id="#+id/loadContent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:padding="20dp">
<RelativeLayout
android:id="#+id/dotRel"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/percentText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginBottom="15dp"
android:text="0 %"
android:textColor="#android:color/black"
android:textSize="25sp" />
<ProgressBar
android:id="#+id/mProgressBar"
style="#android:style/Widget.ProgressBar.Horizontal"
android:layout_width="match_parent"
android:layout_height="5dp"
android:layout_below="#+id/percentText"
android:progressDrawable="#drawable/progressbar" />
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
Here is the dialog while the file is being copied:
Conclusion:
With the above, your file will be copied to /storage/emulated/0/Android/data/yourPackageName/files/Temp/YourFile.jpg. While the files are being copied a progress dialog will be displayed indicating the progress as a percentage (this is useful for when copying large files). If there was an error while copying the file, the reason will be provided in onCopyPostExecute
This will work with file and content Uri's.

You can try this;
try {
Uri uri = data.getData();
String selectedFilePath = FilePath.getPath(getActivity(), uri);
final File file = new File(selectedFilePath);
new UploadFileToServer().execute(file);
}
catch (Exception e)
{
e.printStackTrace();
}
and define FilePath class like this;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
public class FilePath {
/**
* Method for return file path of Gallery image/ Document / Video / Audio
*
* #param context
* #param uri
* #return path of the selected image file from gallery
*/
public static String getPath(final Context context, final Uri uri) {
// check here to KITKAT or new version
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/"
+ split[1];
}
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"),
Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] { split[1] };
return getDataColumn(context, contentUri, selection,
selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* #param context
* The context.
* #param uri
* The Uri to query.
* #param selection
* (Optional) Filter used in the query.
* #param selectionArgs
* (Optional) Selection arguments used in the query.
* #return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri,
String selection, String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = { column };
try {
cursor = context.getContentResolver().query(uri, projection,
selection, selectionArgs, null);
if (cursor != null && cursor.moveToFirst()) {
final int index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* #param uri
* The Uri to check.
* #return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri
.getAuthority());
}
/**
* #param uri
* The Uri to check.
* #return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri
.getAuthority());
}
/**
* #param uri
* The Uri to check.
* #return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri
.getAuthority());
}
/**
* #param uri
* The Uri to check.
* #return Whether the Uri authority is Google Photos.
*/
public static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri
.getAuthority());
}
}

One line solution for your problem
File imageFile = new File(selectedImageUri.getPath());
You missed
.getPath()

How to create file using android Uri
It may seem difficult to create a java.io.File from an android.net.Uri, since there is no direct way to convert an android.net.Uri into java.net.URI. But if you have the ApplicationContext you can do it very easily.
Here's how to do it from inside a fragment class.
fun createFile(uri: Uri) {
try {
requireContext().applicationContext.contentResolver.openFileDescriptor(uri, "w")?.use { fd ->
FileOutputStream(fd).use { fos ->
// do your job on the FileOutputStream
// also use background thread
fos.close()
}
}
} catch (e: Exception) {
}
}
Note: File operations throws multiple exceptions, so handle them carefully. And also do file operations in worker threads.

you can use this funtion for get file from uri in new android and older:
fun getFileFromUri(context: Context, uri: Uri?): File? {
uri ?: return null
uri.path ?: return null
var newUriString = uri.toString()
newUriString = newUriString.replace(
"content://com.android.providers.downloads.documents/",
"content://com.android.providers.media.documents/"
)
newUriString = newUriString.replace(
"/msf%3A", "/image%3A"
)
val newUri = Uri.parse(newUriString)
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (newUri.path?.contains("/document/image:") == true) {
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(newUri).split(":")[1])
} else {
databaseUri = newUri
selection = null
selectionArgs = null
}
try {
val column = "_data"
val projection = arrayOf(column)
val cursor = context.contentResolver.query(
databaseUri,
projection,
selection,
selectionArgs,
null
)
cursor?.let {
if (it.moveToFirst()) {
val columnIndex = cursor.getColumnIndexOrThrow(column)
realPath = cursor.getString(columnIndex)
}
cursor.close()
}
} catch (e: Exception) {
Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = realPath.ifEmpty {
when {
newUri.path?.contains("/document/raw:") == true -> newUri.path?.replace(
"/document/raw:",
""
)
newUri.path?.contains("/document/primary:") == true -> newUri.path?.replace(
"/document/primary:",
"/storage/emulated/0/"
)
else -> return null
}
}
return if (path.isNullOrEmpty()) null else File(path)
}

Unable to access file from uri

I am trying to access a file using Storage Access Framework which I have stored in locally and send it to server. but when ever I try to get file using URI I get NullPointerException. However I get the URI of file. but catches exception when converting to file by getting path.
Minimum API is 17
uriString =
content://com.android.providers.downloads.documents/document/349
warantyButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(Intent. ACTION_OPEN_DOCUMENT );
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("*/*");
Intent i = Intent.createChooser(intent, "File");
getActivity().startActivityForResult(i, FILE_REQ_CODE);
//Toast.makeText(getContext(),"Files",Toast.LENGTH_SHORT).show();
}
});
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == FILE_REQ_CODE) {
if (resultCode == RESULT_OK) {
String path="";
Uri uri = data.getData();
if (uri != null) {
try {
file = new File(getPath(getContext(),uri));
if(file!=null){
ext = getMimeType(uri);
sendFileToServer(file,ext);
}
} catch (Exception e) {
Toast.makeText(getContext(),getString(R.string.general_error_retry),Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
}
}
}
public static String getPath(Context context, Uri uri) throws URISyntaxException {
if ("content".equalsIgnoreCase(uri.getScheme())) {
String[] projection = { "_data" };
Cursor cursor = null;
try {
cursor = context.getContentResolver().query(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow("_data");
if (cursor.moveToFirst()) {
return cursor.getString(column_index);
}
} catch (Exception e) {
// Eat it
}
}
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}

I am trying to access a file using Storage Access Framework which I have stored in locally and send it to server.
Your users are welcome to choose anything they want, which does not include files that you can access directly (e.g., in Google Drive, on removable storage).
but catches exception when converting to file by getting path
You cannot "convert to file by getting path". The path portion of a content Uri is a meaningless set of characters that identifies the particular piece of content. Next, you will think that all computers have a file on their local filesystem at the path /questions/43818723/unable-to-access-file-from-uri, just because https://stackoverflow.com/questions/43818723/unable-to-access-file-from-uri happens to be a valid Uri.
So, get rid of getPath().
Use ContentResolver and openInputStream() to get an InputStream on the content. Either use that stream directly or use it in conjunction with a FileOutputStream on your own file, to make a local copy of the content that you can use as a file.

#CommonsWare answer is correct
here is code snippet
To read file content from Uri :
// Use ContentResolver to access file from Uri
InputStream inputStream = null;
try {
inputStream = mainActivity.getContentResolver().openInputStream(uri);
assert inputStream != null;
// read file content
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String mLine;
StringBuilder stringBuilder = new StringBuilder();
while ((mLine = bufferedReader.readLine()) != null) {
stringBuilder.append(mLine);
}
Log.d(TAG, "reading file :" + stringBuilder);
To save file from Uri to local copy inside your app dir :
String dirPath = "/data/user/0/-your package name -/newLocalFile.name"
try (InputStream ins = mainActivity.getContentResolver().openInputStream(uri)) {
File dest = new File(dirPath);
try (OutputStream os = new FileOutputStream(dest)) {
byte[] buffer = new byte[4096];
int length;
while ((length = ins.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
os.flush();
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
e.printStackTrace();
}

Try Below Code For Getting Path:
public String getPath(Uri uri) throws URISyntaxException {
final boolean needToCheckUri = Build.VERSION.SDK_INT >= 19;
String selection = null;
String[] selectionArgs = null;
// Uri is different in versions after KITKAT (Android 4.4), we need to
// deal with different Uris.
if (needToCheckUri && DocumentsContract.isDocumentUri(mainActivity, uri)) {
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
return Environment.getExternalStorageDirectory() + "/" + split[1];
} else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
uri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
} else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("image".equals(type)) {
uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
uri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
selection = "_id=?";
selectionArgs = new String[] {
split[1]
};
}
}
if ("content".equalsIgnoreCase(uri.getScheme())) {
String[] projection = {
MediaStore.Images.Media.DATA
};
Cursor cursor = null;
try {
cursor = mainActivity.getContentResolver()
.query(uri, projection, selection, selectionArgs, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
if (cursor.moveToFirst()) {
return cursor.getString(column_index);
}
} catch (Exception e) {
}
} else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}`/**
* #param uri The Uri to check.
* #return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* #param uri The Uri to check.
* #return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* #param uri The Uri to check.
* #return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}`

File picker in xamarin forms application

I using a renderer to pick a file from the system to and showing it in the application. I used
Intent intent = new Intent(Intent.ActionOpenDocument);
intent.SetType("file/*");
intent.AddCategory(Intent.CategoryOpenable);
String[] mimeTypes = { "text/csv", "text/comma-separated-values" ,"application/pdf","image/*"};
intent.SetType("*/*");
intent.PutExtra(Intent.ExtraMimeTypes, mimeTypes);
((FormsAppCompatActivity)Forms.Context).StartActivityForResult(intent, 7007);
And i got the data in OnActivityResult in MainActivity . Now that i have the Android.Net.Uri with me i want to find the absolute file path . here i used
public String getRealPathFromURI(Android.Net.Uri contentUri)
{
String res = null;
String[] proj = {Android.Provider.MediaStore.Images.Media.InterfaceConsts.Data};
ICursor cursor = ContentResolver.Query(contentUri, proj, null, null, null);
if (cursor.MoveToFirst())
{
int column_index = cursor.GetColumnIndexOrThrow(Android.Provider.MediaStore.Images.Media.InterfaceConsts.Data);
res = cursor.GetString(column_index);
}
cursor.Close();
return res;
}
I am testing in a Marshmallow device but i am getting null value as return every time. Any Guidance?

You can take a look to this plugin...
There is a IOUtil.cs class
public class IOUtil
{
public static string getPath (Context context, Android.Net.Uri uri)
{
bool isKitKat = Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat;
// DocumentProvider
if (isKitKat && DocumentsContract.IsDocumentUri (context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument (uri)) {
var docId = DocumentsContract.GetDocumentId (uri);
string [] split = docId.Split (':');
var type = split [0];
if ("primary".Equals (type, StringComparison.OrdinalIgnoreCase)) {
return Android.OS.Environment.ExternalStorageDirectory + "/" + split [1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument (uri)) {
string id = DocumentsContract.GetDocumentId (uri);
Android.Net.Uri contentUri = ContentUris.WithAppendedId (
Android.Net.Uri.Parse ("content://downloads/public_downloads"), long.Parse (id));
return getDataColumn (context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument (uri)) {
var docId = DocumentsContract.GetDocumentId (uri);
string [] split = docId.Split (':');
var type = split [0];
Android.Net.Uri contentUri = null;
if ("image".Equals (type)) {
contentUri = MediaStore.Images.Media.ExternalContentUri;
} else if ("video".Equals (type)) {
contentUri = MediaStore.Video.Media.ExternalContentUri;
} else if ("audio".Equals (type)) {
contentUri = MediaStore.Audio.Media.ExternalContentUri;
}
var selection = "_id=?";
var selectionArgs = new string [] {
split[1]
};
return getDataColumn (context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".Equals (uri.Scheme, StringComparison.OrdinalIgnoreCase)) {
return getDataColumn (context, uri, null, null);
}
// File
else if ("file".Equals (uri.Scheme, StringComparison.OrdinalIgnoreCase)) {
return uri.Path;
}
return null;
}
public static string getDataColumn (Context context, Android.Net.Uri uri, string selection,
string [] selectionArgs)
{
ICursor cursor = null;
var column = "_data";
string [] projection = {
column
};
try {
cursor = context.ContentResolver.Query (uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.MoveToFirst ()) {
int column_index = cursor.GetColumnIndexOrThrow (column);
return cursor.GetString (column_index);
}
} finally {
if (cursor != null)
cursor.Close ();
}
return null;
}
/**
* #param uri The Uri to check.
* #return Whether the Uri authority is ExternalStorageProvider.
*/
public static bool isExternalStorageDocument (Android.Net.Uri uri)
{
return "com.android.externalstorage.documents".Equals (uri.Authority);
}
/**
* #param uri The Uri to check.
* #return Whether the Uri authority is DownloadsProvider.
*/
public static bool isDownloadsDocument (Android.Net.Uri uri)
{
return "com.android.providers.downloads.documents".Equals (uri.Authority);
}
/**
* #param uri The Uri to check.
* #return Whether the Uri authority is MediaProvider.
*/
public static bool isMediaDocument (Android.Net.Uri uri)
{
return "com.android.providers.media.documents".Equals (uri.Authority);
}
public static byte [] readFile (string file)
{
try {
return readFile (new File (file));
} catch (Exception ex) {
System.Diagnostics.Debug.Write (ex);
return new byte [0];
}
}
public static byte [] readFile (File file)
{
// Open file
var f = new RandomAccessFile (file, "r");
try {
// Get and check length
long longlength = f.Length ();
var length = (int)longlength;
if (length != longlength)
throw new IOException ("Filesize exceeds allowed size");
// Read file and return data
byte [] data = new byte [length];
f.ReadFully (data);
return data;
} catch (Exception ex) {
System.Diagnostics.Debug.Write (ex);
return new byte [0];
} finally {
f.Close ();
}
}
public static string GetMimeType (string url)
{
string type = null;
var extension = MimeTypeMap.GetFileExtensionFromUrl (url);
if (extension != null) {
type = MimeTypeMap.Singleton.GetMimeTypeFromExtension (extension);
}
return type;
}
}
it works in this way
protected override void OnActivityResult (int requestCode, [GeneratedEnum] Result resultCode, Intent data)
{
base.OnActivityResult (requestCode, resultCode, data);
if (resultCode == Result.Canceled) {
// Notify user file picking was cancelled.
OnFilePickCancelled ();
Finish ();
} else {
System.Diagnostics.Debug.Write (data.Data);
try {
var _uri = data.Data;
var filePath = IOUtil.getPath (context, _uri);
if (string.IsNullOrEmpty (filePath))
filePath = _uri.Path;
var file = IOUtil.readFile (filePath);
var fileName = GetFileName (context, _uri);
OnFilePicked (new FilePickerEventArgs (file, fileName, filePath));
} catch (Exception readEx) {
// Notify user file picking failed.
OnFilePickCancelled ();
System.Diagnostics.Debug.Write (readEx);
} finally {
Finish ();
}
}
}

Instead of using Android specific code in your Forms project, you can also use one of the FilePicker plugins that are available on NuGet. You can use this directly in your Forms project instead of jumping into an Android implementation.
The currently most actively maintained package is this one: https://github.com/jfversluis/FilePicker-Plugin-for-Xamarin-and-Windows (note: I'm one of the contributors to the project).
Picking files is as easy as calling var result = await PickFile() and checking the result object. See also the sample code mentioned in the README.md of the Github project.

Share Assets Using fileprovider

Followed https://developer.android.com/training/secure-file-sharing/index.html and able to share files in the internal directory(/data/data/package/files/xxx/) of app to client app using fileprovider.
How to share the files in assets folder(instead of internal directory) to the client app.
Thanks

See CWAC-Provider from CommonsWare which is a library to do precisely what you want.

This is the way i used finally, hope this will help someone.
Added provider in manifest file
<provider
android:name=".AssetsProvider"
android:authorities="yourpackage.provider"
android:exported="true"
android:grantUriPermissions="true"
android:readPermission="yourpermission"></provider>
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:screenOrientation="landscape">
<intent-filter>
<action android:name="android.intent.action.PICK" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.OPENABLE" />
<data android:mimeType="application/octet-stream" />
</intent-filter>
</activity>
Following inProvider Activity onCreate() to get assets list and return uriArray to caller (Consumer App)
String[] assetFilesList = null;
// Get Asset Mangaer
AssetManager assetManager = getAssets();
try {
assetFilesList = assetManager.list();
} catch (IOException e) {
Log.e(TAG, Log.getStackTraceString(e));
}
// Set up an Intent to send back to apps that request files
mResultIntent = new Intent("yourpackage.ACTION_SEND_MULTIPLE");
// new Uri list
ArrayList<Uri> uriArrayList = new ArrayList<>();
// Set the Activity's result to null to begin with
setResult(Activity.RESULT_CANCELED, null);
Uri fileUri;
if (assetFilesList != null) {
for (String currFile : assetFilesList) {
Log.i(TAG, "Adding File " + currFile);
// parse and create uri
fileUri = Uri.parse("content://" + this.getPackageName() + ".provider/" + currFile);
// add current file uri to the list
uriArrayList.add(fileUri);
}
}
else {
Log.e(TAG, "files array is pointing to null");
}
if (uriArrayList.size() != 0) {
// Put the UriList Intent
mResultIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uriArrayList);
mResultIntent.setType("application/octet-stream");
// Set the result
this.setResult(Activity.RESULT_OK, mResultIntent);
} else {
// Set the result to failed
mResultIntent.setDataAndType(null, "");
this.setResult(RESULT_CANCELED, mResultIntent);
}
// Finish Activity and return Result to Caller
finish();
My Assets Provider Class, I have not implemented query, update etc... as these are not necessary for my case.
public class AssetsProvider extends ContentProvider {
static final String TAG = "AssetsProvider";
#Override
public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException {
Log.v(TAG, "AssetsGetter: Open asset file " + uri.toString());
AssetManager am = getContext().getAssets();
String file_name = uri.getLastPathSegment();
if (file_name == null)
throw new FileNotFoundException();
AssetFileDescriptor afd = null;
try {
afd = am.openFd(file_name);
} catch (IOException e) {
Log.e(TAG, Log.getStackTraceString(e));
}
return afd;
}
#Override
public String getType(Uri p1) {
// TODO: Implement this method
return null;
}
#Override
public int delete(Uri p1, String p2, String[] p3) {
// TODO: Implement this method
return 0;
}
#Override
public Cursor query(Uri p1, String[] p2, String p3, String[] p4, String p5) {
// TODO: Implement this method
return null;
}
#Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder, CancellationSignal cancellationSignal) {
// TODO: Implement this method
return super.query(uri, projection, selection, selectionArgs, sortOrder, cancellationSignal);
}
#Override
public Uri insert(Uri p1, ContentValues p2) {
// TODO: Implement this method
return null;
}
#Override
public boolean onCreate() {
// TODO: Implement this method
return false;
}
#Override
public int update(Uri p1, ContentValues p2, String p3, String[] p4) {
// TODO: Implement this method
return 0;
}
}
Gradle build options to avoid compression for assets files (these are the types of files i had in assets)
aaptOptions {
noCompress '.json' , '.xls'
}
Following in the Consumer activity
In onCreate() -- setPackage() is required since we want send ACTION_PICK to specific application
Intent mRequestFileIntent = new Intent(Intent.ACTION_PICK);
mRequestFileIntent.setPackage("yourAssetsProviderpackage");
mRequestFileIntent.setType("application/octet-stream");
try {
startActivityForResult(mRequestFileIntent, 0);
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "Install Assets Provider app before start", Toast.LENGTH_LONG).show();
finish();
}
Added Override method onActivityResult()
public void onActivityResult(int requestCode, int resultCode,
Intent returnIntent) {
// If the selection didn't work
if (resultCode != Activity.RESULT_OK) {
// Exit without doing anything else
Log.e(TAG, "Activity returned fail");
} else {
// get array list
ArrayList<Uri> uriArrayList = returnIntent.getParcelableArrayListExtra(Intent.EXTRA_STREAM);
// create directory in internal storage to store the assets from uri list
String toPath = this.getFilesDir().getPath();
if (uriArrayList != null) {
AssetFileDescriptor mInputAFD;
for (int i = 0; i < uriArrayList.size(); i++) {
// Get the file's content URI
Uri returnUri = uriArrayList.get(i);
try {
mInputAFD = getContentResolver().openAssetFileDescriptor(returnUri, "r");
// Get file name
String fileName = returnUri.getLastPathSegment();
Log.i(TAG, "URI " + returnUri.toString() + " fileName " + fileName);
// Create dest filename and copy
File dest = new File(toPath + "/" + fileName);
copyRaw(mInputAFD, dest);
} catch (Exception e) {
Log.e(TAG, Log.getStackTraceString(e));
// Break loop at first exception
break;
}
}
}
}
}
CopyRaw method to copy the file using AssetFileDescriptor
public void copyRaw(AssetFileDescriptor fd, File destinationFile) throws IOException {
FileChannel sourceChannel = new FileInputStream(fd.getFileDescriptor()).getChannel();
FileChannel destinationChannel = new FileOutputStream(destinationFile).getChannel();
sourceChannel.transferTo(fd.getStartOffset(), fd.getLength(), destinationChannel);
}
Add Permission in Consumer manifest file
<uses-permission android:name="yourpermission" />

Share SQLite database from Android app, without intermediate copy

I want to allow users of my Android app to export the SQLite database file for content they create. My current solution copies the file to private storage (/data/data/com.package.name/files/Content.db), then creates a URI for this file and opens the Share dialog. This is working, allowing me to export the database file using Dropbox, for example. Here is the code I'm using, partially adapted from https://stackoverflow.com/a/2661882 -
private void exportContent() {
copyContentToPrivateStorage();
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("application/octet-stream");
Uri uri = new FileProvider().getDatabaseURI(this);
intent.putExtra(Intent.EXTRA_STREAM, uri);
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivity(Intent.createChooser(intent, "Backup via:"));
}
private void copyContentToPrivateStorage() {
// From https://stackoverflow.com/a/2661882
try {
File data = Environment.getDataDirectory();
File sd = getFilesDir();
if (sd.canWrite()) {
String currentDBPath = "//data//com.package.name//databases//Content.db";
String backupDBPath = "Content.db";
File currentDB = new File(data, currentDBPath);
File backupDB = new File(sd, backupDBPath);
if (currentDB.exists()) {
FileChannel src = new FileInputStream(currentDB).getChannel();
FileChannel dst = new FileOutputStream(backupDB).getChannel();
dst.transferFrom(src, 0, src.size());
src.close();
dst.close();
}
}
} catch (Exception e) {
Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
}
}
public class FileProvider extends android.support.v4.content.FileProvider {
public Uri getDatabaseURI(Context c) {
File exportFile = new File(c.getFilesDir(), "Content.db");
Uri uri = getUriForFile(c, "com.package.name.fileprovider", exportFile);
c.grantUriPermission("*", uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
return uri;
}
}
It seems like I should be able to directly create a URI from the existing database path, instead of doing an intermediate copy. Is there a way to do this?
I could keep doing the intermediate copy, but I believe it would be bad practice to leave the second copy of the database in the data directory longer than necessary. Is there a way to clean it up and delete it after the chosen app has finished using the URI to share the file?

I solved this on my own. I'm documenting it here, per Neil's request.
This is where I launch the export/backup from my activity:
public class MyActivity {
private void exportUserContent() {
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("application/octet-stream");
Uri uri = new FileProvider().getDatabaseURI(this);
intent.putExtra(Intent.EXTRA_STREAM, uri);
startActivity(Intent.createChooser(intent, "Backup via:"));
}
}
The FileProvider:
public class FileProvider extends android.support.v4.content.FileProvider {
public Uri getDatabaseURI(Context c) {
// https://developer.android.com/reference/android/support/v4/content/FileProvider.html
// old approach that worked until 2020-ish
// File data = Environment.getDataDirectory();
// String dbName = "UserContent.db";
// String currentDBPath = "//data//com.url.myapp//databases//" + dbName;
// File exportFile = new File(data, currentDBPath);
File exportFile = c.getDatabasePath(dbName); // new approach
return getFileUri(c, exportFile);
}
public Uri getFileUri(Context c, File f){
return getUriForFile(c, "com.url.myapp.fileprovider", f);
}
}
Inside AndroidManifest.xml:
<manifest ...>
<application ...>
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="com.url.myapp.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/filepaths" />
</provider>
Inside \app\src\main\res\xml\filepaths.xml
(I think the first entry is the relevant one, but I'll include the whole file for completeness):
<paths>
<files-path
path="../databases/"
name="mydatabases"/>
<files-path
path=""
name="migrations"/>
<external-path
path=""
name="external"/>
</paths>

Share the SQLite database using content providers. This tutorial can guide you more on SQLite database and content provider: Android SQLite DB and Content Provider

Here's how I solved this with a custom ContentProvider:
import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.net.Uri;
import android.os.ParcelFileDescriptor;
import android.provider.OpenableColumns;
import java.io.File;
import java.io.FileNotFoundException;
/**
* ContentProvider to share SQLite database
*
* Credit: https://android.googlesource.com/platform/frameworks/support/+/android-support-lib-19.1.0/v4/java/android/support/v4/content/FileProvider.java
*/
public class MyProvider extends ContentProvider {
private final File file = new File("/data/data/com.example.provider/databases", "mydatabase.db");
#Override
public boolean onCreate() {
return true;
}
#Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
if (projection == null) {
projection = new String[] { OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE };
}
String[] cols = new String[projection.length];
Object[] values = new Object[projection.length];
int i = 0;
for (String col : projection) {
if (OpenableColumns.DISPLAY_NAME.equals(col)) {
cols[i] = OpenableColumns.DISPLAY_NAME;
values[i++] = file.getName();
} else if (OpenableColumns.SIZE.equals(col)) {
cols[i] = OpenableColumns.SIZE;
values[i++] = file.length();
}
}
cols = copyOf(cols, i);
values = copyOf(values, i);
final MatrixCursor cursor = new MatrixCursor(cols, 1);
cursor.addRow(values);
return cursor;
}
#Override
public String getType(Uri uri) {
return "application/octet-stream";
}
#Override
public Uri insert(Uri uri, ContentValues values) {
throw new UnsupportedOperationException("No external inserts");
}
#Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
throw new UnsupportedOperationException("No external updates");
}
#Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return 0;
}
#Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
}
private static String[] copyOf(String[] original, int newLength) {
final String[] result = new String[newLength];
System.arraycopy(original, 0, result, 0, newLength);
return result;
}
private static Object[] copyOf(Object[] original, int newLength) {
final Object[] result = new Object[newLength];
System.arraycopy(original, 0, result, 0, newLength);
return result;
}
}
Then in the manifest:
<provider
android:name="com.example.appname.MyProvider"
android:authorities="com.example.provider">
</provider>

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

android share images from assets folder - android

AFAIK, there's no way to share an image from the assets folder. But it's possible to share resources from the res folder.

To share from assets folder I can only recommend the cwac-provider library (StreamProvider). Among avoiding to develop your own content provider, it adds some support for capricious legacy apps (check USE_LEGACY_CURSOR_WRAPPER).

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