Scoped Storage Example

Deepak Rawat

11 October 2021

Scoped storage was a feature introduced in Android Q(10). This is now mandatory from Android 11 that all apps targeting this version have scoped storage implemented, these new improvements have privacy in mind.
In preview versions of android before Android 10, the runtime permission to read or write was required to access almost every file on disk, the Scoped storage feature is introduced mainly to avoid this situation. You can also check the official documentation: Click Here

Manage device storage

From Android 11, the apps can use the scoped storage model can access only their own app-specific cache files.
If your app needs to manage device storage check the below action to free the space.

1. Check for free space by invoking the ACTION_MANAGE_STORAGE intent action.
2. If there isn’t enough free space on the device, prompt the user to give your app consent to clear all caches.
To do so, invoke the ACTION_CLEAR_APP_CACHE intent action(It might affect device battery life and might remove a large number of files from the device.).

Let’s write a sample code to access storage.

AndroidManifest.xml for permission:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_MEDIA_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
android:maxSdkVersion="28"
/>

<uses-permission android:name="android.permission.INTERNET"/>

<uses-permission android:name="android.permission.ACCESS_MEDIA_LOCATION" />

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

android:maxSdkVersion="28"

ConstantHelpers.kt:

object ConstantHelpers {
const val OPEN_FILE_REQUEST_CODE = 2001
const val OPEN_FOLDER_REQUEST_CODE = 2002
const val CHOOSE_FILE = 2003
const val READ_EXTERNAL_STORAGE_PERMISSION = 2004
const val CREATE_FILE_REQUEST_CODE = 2005

var downloadUrl = "https://mobikuldemo.webkul.com/mobikulmp/pub/media/mobikul/splash/1080x2160/default/black_mp.jpg"

}

object ConstantHelpers {

const val OPEN_FILE_REQUEST_CODE = 2001

const val OPEN_FOLDER_REQUEST_CODE = 2002

const val CHOOSE_FILE = 2003

const val READ_EXTERNAL_STORAGE_PERMISSION = 2004

const val CREATE_FILE_REQUEST_CODE = 2005

var downloadUrl = "https://mobikuldemo.webkul.com/mobikulmp/pub/media/mobikul/splash/1080x2160/default/black_mp.jpg"

}

MainActivity.kt:

/*
This code is for Android 10 and above, if you are using the below android devices then you have to Handle the below version as per the older runtime permission required.
*/
class MainActivity : AppCompatActivity() {

lateinit var mContentViewBinding: ActivityMainBinding

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
mContentViewBinding = DataBindingUtil.setContentView(this, R.layout.activity_main)

clickListeners()
}

private fun clickListeners() {
mContentViewBinding.createFileBt.setOnClickListener {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
if (permissionToReadWrite) {
createFile()
} else {
permissionForReadWrite()
}
} else {
createFile()
}
}

mContentViewBinding.openFileBt.setOnClickListener {
openFile()
}

mContentViewBinding.openFolderBt.setOnClickListener {
openFolder()
}

mContentViewBinding.downloadImageDownloadBt.setOnClickListener {
downloadImage()
}
mContentViewBinding.downloadImageAppFolderBt.setOnClickListener {
downloadImageToAppFolder()
}
}

private fun createFile() {

val intent = Intent(Intent.ACTION_CREATE_DOCUMENT)
intent.addCategory(Intent.CATEGORY_OPENABLE)
intent.type = "text/plain"
intent.putExtra(Intent.EXTRA_TITLE, "Test.txt")
startActivityForResult(intent, CREATE_FILE_REQUEST_CODE)
}

private fun writeFileContent(uri: Uri?) {
try {
val file = uri?.let { this.contentResolver.openFileDescriptor(it, "w") }

file?.let {
val fileOutputStream = FileOutputStream(
it.fileDescriptor
)
val textContent = "This is the dummy text."

fileOutputStream.write(textContent.toByteArray())

fileOutputStream.close()
it.close()
}

} catch (e: FileNotFoundException) {
//print logs
} catch (e: IOException) {
//print logs
}

}

private fun downloadImage() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
if (permissionToReadWrite) {
downloadImageToDownloadFolder()
} else {
permissionForReadWrite()
}

} else {
downloadImageToDownloadFolder()
}
}

private fun downloadImageToAppFolder() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
if (permissionToReadWrite) {
downloadToAppFolder()
} else {
permissionForReadWrite()
}

} else {
downloadToAppFolder()
}
}

//Downloading file to Internal Folder
private fun downloadToAppFolder() {
try {
val file = File(
this.getExternalFilesDir(
null
), "test2.png"
)

if (!file.exists())
file.createNewFile()

var fileOutputStream: FileOutputStream? = null

fileOutputStream = FileOutputStream(file)
val bitmap = (ContextCompat.getDrawable(this, R.drawable.test) as BitmapDrawable).bitmap

bitmap?.compress(Bitmap.CompressFormat.PNG, 80, fileOutputStream)
Toast.makeText(
applicationContext,
getString(R.string.download_successful) + file.absolutePath,
Toast.LENGTH_LONG
).show()
} catch (e: Exception) {
e.printStackTrace()
}
}

private var permissionToReadWrite: Boolean = false
get() {
val permissionGrantedResult: Int = ContextCompat.checkSelfPermission(
this,
android.Manifest.permission.READ_EXTERNAL_STORAGE
)
return permissionGrantedResult == PackageManager.PERMISSION_GRANTED
}

//Request Permission For Read Storage
private fun permissionForReadWrite() {
ActivityCompat.requestPermissions(
this,
arrayOf(
android.Manifest.permission.READ_EXTERNAL_STORAGE
), READ_EXTERNAL_STORAGE_PERMISSION
)
}

private fun downloadImageToDownloadFolder() {
val mgr = getSystemService(Context.DOWNLOAD_SERVICE) as DownloadManager

val downloadUri = Uri.parse(downloadUrl)
val request = DownloadManager.Request(
downloadUri
)
request.setAllowedNetworkTypes(
DownloadManager.Request.NETWORK_WIFI or DownloadManager.Request.NETWORK_MOBILE
)
.setAllowedOverRoaming(false).setTitle("Image Sample")
.setDescription("Testing")
.setDestinationInExternalPublicDir(
Environment.DIRECTORY_DOWNLOADS,
"test1.jpg"
)

Toast.makeText(
applicationContext,
"Downloaded successfully to ${downloadUri?.path}",
Toast.LENGTH_LONG
).show()

mgr.enqueue(request)

}

private fun openFolder() {
val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE).apply {
flags = Intent.FLAG_GRANT_READ_URI_PERMISSION or
Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION
}
startActivityForResult(intent, OPEN_FOLDER_REQUEST_CODE)
}

private fun openFile() {
val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
//if you want to open PDF file
type = "application/pdf"
addCategory(Intent.CATEGORY_OPENABLE)
//Adding Read URI permission
flags = flags or Intent.FLAG_GRANT_READ_URI_PERMISSION
}
startActivityForResult(intent, OPEN_FILE_REQUEST_CODE)
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
if (resultCode == Activity.RESULT_OK) {
if (requestCode == OPEN_FILE_REQUEST_CODE) {
data?.data?.also { documentUri ->
//Permission needed if you want to retain access even after reboot
contentResolver.takePersistableUriPermission(
documentUri,
Intent.FLAG_GRANT_READ_URI_PERMISSION
)
Toast.makeText(this, documentUri.path.toString(), Toast.LENGTH_LONG).show()
}
} else if (requestCode == OPEN_FOLDER_REQUEST_CODE) {
val directoryUri = data?.data ?: return

//Taking permission to retain access
contentResolver.takePersistableUriPermission(
directoryUri,
Intent.FLAG_GRANT_READ_URI_PERMISSION
)
//Now you have access to the folder, you can easily view the content or do whatever you want.
val documentsTree = DocumentFile.fromTreeUri(application, directoryUri) ?: return
val childDocuments = documentsTree.listFiles().asList()
Toast.makeText(
this,
"Total Items Under this folder =" + childDocuments.size.toString(),
Toast.LENGTH_LONG
).show()

} else if (requestCode == CHOOSE_FILE)
else if (requestCode == CREATE_FILE_REQUEST_CODE) {
if (data != null) {
writeFileContent(data.data)
}

}
}
}
}

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This code is for Android 10 and above, if you are using the below android devices then you have to Handle the below version as per the older runtime permission required.

class MainActivity : AppCompatActivity() {

lateinit var mContentViewBinding: ActivityMainBinding

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

mContentViewBinding = DataBindingUtil.setContentView(this, R.layout.activity_main)

clickListeners()

}

private fun clickListeners() {

mContentViewBinding.createFileBt.setOnClickListener {

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {

if (permissionToReadWrite) {

createFile()

} else {

permissionForReadWrite()

}

} else {

createFile()

}

mContentViewBinding.openFileBt.setOnClickListener {

openFile()

}

mContentViewBinding.openFolderBt.setOnClickListener {

openFolder()

}

mContentViewBinding.downloadImageDownloadBt.setOnClickListener {

downloadImage()

}

mContentViewBinding.downloadImageAppFolderBt.setOnClickListener {

downloadImageToAppFolder()

}

private fun createFile() {

val intent = Intent(Intent.ACTION_CREATE_DOCUMENT)

intent.addCategory(Intent.CATEGORY_OPENABLE)

intent.type = "text/plain"

intent.putExtra(Intent.EXTRA_TITLE, "Test.txt")

startActivityForResult(intent, CREATE_FILE_REQUEST_CODE)

}

private fun writeFileContent(uri: Uri?) {

try {

val file = uri?.let { this.contentResolver.openFileDescriptor(it, "w") }

file?.let {

val fileOutputStream = FileOutputStream(

it.fileDescriptor

)

val textContent = "This is the dummy text."

fileOutputStream.write(textContent.toByteArray())

fileOutputStream.close()

it.close()

}

} catch (e: FileNotFoundException) {

//print logs

} catch (e: IOException) {

//print logs

}

private fun downloadImage() {

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {

if (permissionToReadWrite) {

downloadImageToDownloadFolder()

} else {

permissionForReadWrite()

}

} else {

downloadImageToDownloadFolder()

}

private fun downloadImageToAppFolder() {

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {

if (permissionToReadWrite) {

downloadToAppFolder()

} else {

permissionForReadWrite()

}

} else {

downloadToAppFolder()

}

//Downloading file to Internal Folder

private fun downloadToAppFolder() {

try {

val file = File(

this.getExternalFilesDir(

null

), "test2.png"

)

if (!file.exists())

file.createNewFile()

var fileOutputStream: FileOutputStream? = null

fileOutputStream = FileOutputStream(file)

val bitmap = (ContextCompat.getDrawable(this, R.drawable.test) as BitmapDrawable).bitmap

bitmap?.compress(Bitmap.CompressFormat.PNG, 80, fileOutputStream)

Toast.makeText(

applicationContext,

getString(R.string.download_successful) + file.absolutePath,

Toast.LENGTH_LONG

).show()

} catch (e: Exception) {

e.printStackTrace()

}

private var permissionToReadWrite: Boolean = false

get() {

val permissionGrantedResult: Int = ContextCompat.checkSelfPermission(

this,

android.Manifest.permission.READ_EXTERNAL_STORAGE

)

return permissionGrantedResult == PackageManager.PERMISSION_GRANTED

}

//Request Permission For Read Storage

private fun permissionForReadWrite() {

ActivityCompat.requestPermissions(

this,

arrayOf(

android.Manifest.permission.READ_EXTERNAL_STORAGE

), READ_EXTERNAL_STORAGE_PERMISSION

)

}

private fun downloadImageToDownloadFolder() {

val mgr = getSystemService(Context.DOWNLOAD_SERVICE) as DownloadManager

val downloadUri = Uri.parse(downloadUrl)

val request = DownloadManager.Request(

downloadUri

)

request.setAllowedNetworkTypes(

DownloadManager.Request.NETWORK_WIFI or DownloadManager.Request.NETWORK_MOBILE

)

.setAllowedOverRoaming(false).setTitle("Image Sample")

.setDescription("Testing")

.setDestinationInExternalPublicDir(

Environment.DIRECTORY_DOWNLOADS,

"test1.jpg"

)

Toast.makeText(

applicationContext,

"Downloaded successfully to ${downloadUri?.path}",

Toast.LENGTH_LONG

).show()

mgr.enqueue(request)

}

private fun openFolder() {

val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE).apply {

flags = Intent.FLAG_GRANT_READ_URI_PERMISSION or

Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION

}

startActivityForResult(intent, OPEN_FOLDER_REQUEST_CODE)

}

private fun openFile() {

val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {

//if you want to open PDF file

type = "application/pdf"

addCategory(Intent.CATEGORY_OPENABLE)

//Adding Read URI permission

flags = flags or Intent.FLAG_GRANT_READ_URI_PERMISSION

}

startActivityForResult(intent, OPEN_FILE_REQUEST_CODE)

}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {

super.onActivityResult(requestCode, resultCode, data)

if (resultCode == Activity.RESULT_OK) {

if (requestCode == OPEN_FILE_REQUEST_CODE) {

data?.data?.also { documentUri ->

//Permission needed if you want to retain access even after reboot

contentResolver.takePersistableUriPermission(

documentUri,

Intent.FLAG_GRANT_READ_URI_PERMISSION

)

Toast.makeText(this, documentUri.path.toString(), Toast.LENGTH_LONG).show()

}

} else if (requestCode == OPEN_FOLDER_REQUEST_CODE) {

val directoryUri = data?.data ?: return

//Taking permission to retain access

contentResolver.takePersistableUriPermission(

directoryUri,

Intent.FLAG_GRANT_READ_URI_PERMISSION

)

//Now you have access to the folder, you can easily view the content or do whatever you want.

val documentsTree = DocumentFile.fromTreeUri(application, directoryUri) ?: return

val childDocuments = documentsTree.listFiles().asList()

Toast.makeText(

this,

"Total Items Under this folder =" + childDocuments.size.toString(),

Toast.LENGTH_LONG

).show()

} else if (requestCode == CHOOSE_FILE)

else if (requestCode == CREATE_FILE_REQUEST_CODE) {

if (data != null) {

writeFileContent(data.data)

}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<layout>

<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/nested_scroll"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<androidx.appcompat.widget.LinearLayoutCompat
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical">

<Button
android:id="@+id/create_file_bt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="@dimen/spacing_normal"
android:layout_marginTop="@dimen/spacing_huge"
android:layout_marginEnd="@dimen/spacing_normal"
android:padding="@dimen/spacing_normal"
android:text="@string/create_a_dummy_file" />

<Button
android:id="@+id/open_file_bt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/spacing_normal"
android:padding="@dimen/spacing_normal"
android:text="@string/open_files" />

<Button
android:id="@+id/open_folder_bt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/spacing_normal"
android:padding="@dimen/spacing_normal"
android:text="@string/open_folder" />

<Button
android:id="@+id/download_image_download_bt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/spacing_normal"
android:padding="@dimen/spacing_normal"
android:text="@string/download_image_url_to_downloads" />

<Button
android:id="@+id/download_image_app_folder_bt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/spacing_normal"
android:padding="@dimen/spacing_normal"
android:text="@string/download_image_to_app_folder" />

</androidx.appcompat.widget.LinearLayoutCompat>
</androidx.core.widget.NestedScrollView>

</layout>

<?xml version="1.0" encoding="utf-8"?>

<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@+id/nested_scroll"

android:layout_width="match_parent"

android:layout_height="wrap_content">

<androidx.appcompat.widget.LinearLayoutCompat

android:layout_width="match_parent"

android:layout_height="match_parent"

android:gravity="center"

android:orientation="vertical">

<Button

android:id="@+id/create_file_bt"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_marginStart="@dimen/spacing_normal"

android:layout_marginTop="@dimen/spacing_huge"

android:layout_marginEnd="@dimen/spacing_normal"

android:padding="@dimen/spacing_normal"

android:text="@string/create_a_dummy_file" />

<Button

android:id="@+id/open_file_bt"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="@dimen/spacing_normal"

android:padding="@dimen/spacing_normal"

android:text="@string/open_files" />

<Button

android:id="@+id/open_folder_bt"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="@dimen/spacing_normal"

android:padding="@dimen/spacing_normal"

android:text="@string/open_folder" />

<Button

android:id="@+id/download_image_download_bt"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="@dimen/spacing_normal"

android:padding="@dimen/spacing_normal"

android:text="@string/download_image_url_to_downloads" />

<Button

android:id="@+id/download_image_app_folder_bt"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="@dimen/spacing_normal"

android:padding="@dimen/spacing_normal"

android:text="@string/download_image_to_app_folder" />

</androidx.appcompat.widget.LinearLayoutCompat>

</androidx.core.widget.NestedScrollView>

</layout>

string.xml:

<resources>
<string name="app_name">Scoped Storage Example</string>
<string name="file_operations_demo">File Operations Demo</string>
<string name="create_a_dummy_file">Create a Dummy File</string>
<string name="open_files">Open files</string>
<string name="open_folder">Open Folder</string>
<string name="download_image_to_app_folder">Download Image to App Folder</string>
<string name="download_image_url_to_downloads">Download Image from Url to Downloads</string>
<string name="download_successful">Image Download successful to: </string>
</resources>

<string name="app_name">Scoped Storage Example</string>

<string name="file_operations_demo">File Operations Demo</string>

<string name="create_a_dummy_file">Create a Dummy File</string>

<string name="open_files">Open files</string>

<string name="open_folder">Open Folder</string>

<string name="download_image_to_app_folder">Download Image to App Folder</string>

<string name="download_image_url_to_downloads">Download Image from Url to Downloads</string>

<string name="download_successful">Image Download successful to: </string>

</resources>

dimens.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<dimen name="text_size_large">30sp</dimen>
<dimen name="spacing_normal">8dp</dimen>
<dimen name="spacing_huge">48dp</dimen>
</resources>

<?xml version="1.0" encoding="utf-8"?>

</resources>

. . . . . . . . .

That’s it from my side for today, thanks for reading it until now. You can check our other android blogs Click Here.