Develop Reference

How to write a file in android shared internal/external storage?

I am currently working with one of my app updates and I am looking for a way to save some files at the root of shared internal storage.
Don't confuse with the word shared here. I just meant here with the phone's internal/external storage which holds a large amount of data.
Now coming to the main point, I have an app that uses the FFmpeg library for android and it records the live streams and saves it into the phone's storage.
Now here's the problem I don't want to save this file in my app package folder.
e.g: /storage/emulated/0/Android/data/com.app.package/files/...
I want to save this video file in the root of the storage folder where I can create a special folder for my app just like WhatsApp then save all required data in it only.
e.g: /storage/emulated/0/MyApp/...
To be more concise I want my app just like WhatsApp which has a separate folder in internal storage for storing its app-related data.
Now, so far I tried these.
getExternalFilesDir(null)?.absolutePath -> /storage/emulated/0/Android/data/com.app.package/files
getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)?.absolutePath -> /storage/emulated/0/Android/data/com.app.package/files/Download
externalCacheDir?.absolutePath -> /storage/emulated/0/Android/data/com.app.package/cache
filesDir?.absolutePath -> /data/user/0/com.app.package/files
Environment.getRootDirectory().absolutePath -> /system
Environment.getExternalStorageDirectory().absolutePath -> /storage/emulated/0
Environment.getExternalStoragePublicDirectory("").absolutePath -> /storage/emulated/0
Now these to methods can work for me but they are deprecated getExternalStorageDirectory() & getExternalStoragePublicDirectory()
Just keep in mind my solution is related to the WhatsApp storage folder.
I searched a lot but not so much help as I don't want to go with just a copy-paste and hack solutions. I want to do it in a clean way.
I am trying to open a File Picker via intent for this I have set permission
....
....
and for intent.
val intent = Intent(Intent.ACTION_OPEN_DOCUMENT)
intent.type = "*/*"
intent.flags = Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
startActivityForResult(Intent.createChooser(intent, "Select .... file"), RC)
Now here on Android 10, a file picker is not opening and this works perfectly if I add the requestLegacyExternalStorage flag in the manifest.
Or
if I set android:maxSdkVersion="29" also worked but here google wants to use Some SAF or Media Store API but I don't get it I just want to pick a file just a simple txt nothing else.

You can save video file to external storage using this:
#RequiresApi(api = Build.VERSION_CODES.Q)
#Throws(FileNotFoundException::class)
fun addToApiAbove29Gallery(
context: Context,
file: File?,
fileName: String?,
destinationPath: String?,
action: () -> Unit
) {
val valuesvideos: ContentValues
valuesvideos = ContentValues()
valuesvideos.put(
MediaStore.Video.Media.RELATIVE_PATH, Environment.DIRECTORY_DCIM
+ File.separator + context.resources.getString(R.string.app_name)
+ File.separator + File(destinationPath).name
)
valuesvideos.put(MediaStore.Video.Media.TITLE, "${fileName}.mp4")
valuesvideos.put(MediaStore.Video.Media.DISPLAY_NAME, "${fileName}.mp4")
valuesvideos.put(MediaStore.Video.Media.MIME_TYPE, "video/mp4")
valuesvideos.put(MediaStore.Video.Media.DATE_ADDED, System.currentTimeMillis() / 1000)
valuesvideos.put(MediaStore.Video.Media.DATE_TAKEN, System.currentTimeMillis())
valuesvideos.put(MediaStore.Video.Media.IS_PENDING, 1)
val resolver = context.contentResolver
val collection = MediaStore.Video.Media.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val uriSavedVideo = resolver.insert(collection, valuesvideos)
val pfd = context.contentResolver.openFileDescriptor(uriSavedVideo!!, "w")
val executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors())
val handler = Handler(Looper.getMainLooper())
executor.execute {
if (pfd != null) {
try {
val out =
FileOutputStream(pfd.fileDescriptor)
val inputStream = FileInputStream(file)
val buf = ByteArray(8192)
var len: Int
while (inputStream.read(buf).also { len = it } > 0) {
out.write(buf, 0, len)
}
out.close()
inputStream.close()
pfd.close()
valuesvideos.clear()
valuesvideos.put(MediaStore.Video.Media.IS_PENDING, 0)
try {
setExifFromUri(
context,
uriSavedVideo,
File(destinationPath)
)
} catch (e: IOException) {
e.printStackTrace()
}
} catch (e: Exception) {
e.printStackTrace()
}
handler.post {
context.contentResolver.update(uriSavedVideo, valuesvideos, null, null)
action()
}
}
}
}
Note that this code is only for android 10 and above, because you can easily save the video file to ecternal storage below android 10.

How to get path /storage/emulated/0/Download/file_name.mime_type for Android 10 and above

I am saving a file inside the Downloads directory of the device (Android 11) to be viewed later by my app. I'm allowing multiple file types like pdf, word etc. I was able to save the file like this: (I got this code sample from here)
#TargetApi(29)
private suspend fun downloadQ(
url: String,
filename: String,
mimeType: String
) =
withContext(Dispatchers.IO) {
val response = ok.newCall(Request.Builder().url(url).build()).execute()
if (response.isSuccessful) {
val values = ContentValues().apply {
put(MediaStore.Downloads.DISPLAY_NAME, filename)
put(MediaStore.Downloads.MIME_TYPE, mimeType)
put(MediaStore.Downloads.IS_PENDING, 1)
}
val resolver = context.contentResolver
val uri =
resolver.insert(MediaStore.Downloads.EXTERNAL_CONTENT_URI, values)
uri?.let {
resolver.openOutputStream(uri)?.use { outputStream ->
val sink = outputStream.sink().buffer()
response.body()?.source()?.let { sink.writeAll(it) }
sink.close()
}
values.clear()
values.put(MediaStore.Downloads.IS_PENDING, 0)
resolver.update(uri, values, null, null)
} ?: throw RuntimeException("MediaStore failed for some reason")
} else {
throw RuntimeException("OkHttp failed for some reason")
}
}
But when I tried to retrieve the file, I tried with the following ways that did not work:
val idColumn = cursor.getColumnIndexOrThrow(MediaStore.Downloads._ID)
val id = cursor.getLong(idColumn)
Log.d("uri id ","$id")
val contentUri = ContentUris.withAppendedId(MediaStore.Downloads.EXTERNAL_CONTENT_URI,id)
This approach threw an exception:
java.lang.IllegalArgumentException: Failed to find configured root that contains /external/downloads/78
I got this ID (here 78) from the query and cursor from ContentResolver.query() and I hoped it to return the Uri from which I could get the File.
The second approach was this:
val uri = MediaStore.Downloads.getContentUri("external",id)
uri.path?.let { filePath ->
Log.d("uri path ",filePath)
val file = File(filePath)
} ?: Log.d("uri path ","null")
I used external as the directory based on this answer, but this approach also threw the same exception
java.lang.IllegalArgumentException: Failed to find configured root that contains /external/downloads/78
At the end what ended up working was hardcoding something like this after I used a file explorer app to view the exact directory path:
val file = File("storage/emulated/0/Download/$name.$extension")
So my question is, how do I get the value of this path dynamically, and is this path the same for all devices that can be used like this way?
EDIT: I also wanted to know if I am using the filename and it's extension to view the file, then if user downloads another file with same name then how do I make sure that correct file is opened? (even if i make a separate directory for my app inside Download, user could still download the same file twice that has a name like storage/emulated/0/Download/myDir/file(2).extension )

Try with the following code it will help you.
private fun readFile(){
val FILENAME = "user_details.txt"
val dir = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
File(
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
.toString() + "/" + "folderName"
)
} else {
File(
Environment.getExternalStorageDirectory()
.toString() + "/${Environment.DIRECTORY_DOWNLOADS}/" + "folderName"
)
}
dir.apply {
if(this.exists()) File(this, FILENAME).apply {
FileInputStream(this).apply {
val stringBuffer = StringBuffer()
var i: Int
while (this.read().also { i = it } != -1) {
stringBuffer.append(i.toChar())
}
close()
}
}
}
}

You can use
{Environment.DIRECTORY_DOWNLOADS} + "/folderName/file_name.mime_type"

/storage/emulated/0/Download/12d82c65-00a5-4c0a-85bc-238c28005c33.bin

How to delete a temporary file in Download folder on Android 10

Simple to do in every system but Android, but I have and app that needs to create a csv file in SHARED EXTERNAL Download folder. Shutdown/restart phone/app and the file persist. Then I need to delete the file (persistent URI somewhere?) before I recreate it with new data. (if exists() delete)
I see all kinds of doc pointing to SAF for this process, but can find no examples anywhere of how to perform this simple process of create/delete. If is can do this on API 28 and it work on 29+ that would be great.
Without SAF I've done this:
fun writeCSV() {
val CSV_HEADER = "Last,First\n"
val mockData = "Tester,Joe\n"
val contentValues = ContentValues()
contentValues.put(MediaStore.Downloads.DISPLAY_NAME, "aTest.csv")
contentValues.put(MediaStore.Downloads.MIME_TYPE, "text/csv")
contentValues.put(MediaStore.Downloads.IS_PENDING, true)
val uri = MediaStore.Downloads.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val fileUri = contentResolver.insert(uri, contentValues)
if (fileUri != null) {
try {
val outputStream = contentResolver.openOutputStream(fileUri)
outputStream!!.write(CSV_HEADER.toByteArray())
outputStream!!.write(mockData.toByteArray())
outputStream!!.close()
contentValues.put(MediaStore.Images.Media.IS_PENDING, false)
contentResolver.update(fileUri, contentValues, null, null)
} catch (e: IOException) {
e.printStackTrace()
}
}
}
The problem is when fun is called again I need to delete this file and recreate it with new data because Android creates "aTest (1).csv" instead of overwriting it.

How can we access an expansion file in Android Q?

I'm writing an app that needs an expansion file and I want to ensure it will be compatible with Android Q. It seems the documentation provided does not address the changes in Android Q. In Android Q, getExternalStorageDirectory() won't be able to be used so how can we access the expansion file?

From the documentation linked to in the question, we know that an expansion file's name has the form:
[main|patch].<expansion-version>.<package-name>.obb
and the getObbDir() method returns the specific location for expansion files in the following form:
<shared-storage>/Android/obb/<package-name>/
So, the question is how do we access such files?
To answer this question, I have taken a directory containing five APK files and created an OBB file named "main.314159.com.example.opaquebinaryblob.obb" using JOBB. My intention is to mount and read this OBB file to display the APK file names and the count of entries in each APK (read as Zip files) in a small demo app.
The demo app will also try to create/read test files in various directories under the external storage directory.
The following was performed on a Pixel XL emulator running the latest available version of "Q" (Android 10.0 (Google APIs)). The app has the following characterisics:
targetSdkVersion 29
minSdkVersion 18
No explicit permissions
specified in the manifest
I peeked ahead to see what directory getObbDir() returns for this little app and found that it is
/storage/emulated/0/Android/obb/com.example.opaquebinaryblob
so I uploaded my OBB file to
/storage/emulated/0/Android/obb/com.example.opaquebinaryblob/main.314159.com.example.opaquebinaryblob.obb
using Android Studio. Here is where the file wound up.
So, can we mount and read this OBB file? Can we create/read files in other directories within the external files path? Here is what the app reports on API 29:
The only files that are accessible reside in /storage/emulated/0/Android/obb/com.example.opaquebinaryblob. Other files in the hierarchy cannot be either created or read. (Interestingly, though, the existence of these files could be determined.)
For the preceding display, the app opens the OBB file and reads it directly without mounting it.
When we try to mount the OBB file and dump its contents, this is what is reported:
Which is what we expect. In short, it looks like Android Q is restricting access to the external files directory while allowing targeted access based up the package name of the app.
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var myObbFile: File
private lateinit var mStorageManager: StorageManager
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
obbDumpText.movementMethod = ScrollingMovementMethod()
val sb = StringBuilder()
val extStorageDir = Environment.getExternalStorageDirectory()
sb.appendln("getExternalStorageDirectory() reported at $extStorageDir").appendln()
myObbFile = File(obbDir, BLOB_FILE_NAME)
val obbDir = obbDir
sb.appendln("obbDir reported at $obbDir").appendln()
myObbFile = File(obbDir, BLOB_FILE_NAME)
val directoryPathList = listOf(
"$extStorageDir",
"$extStorageDir/Pictures",
"$extStorageDir/Android/obb/com.example.anotherpackage",
"$extStorageDir/Android/obb/$packageName"
)
var e: Exception?
for (directoryPath in directoryPathList) {
val fileToCheck = File(directoryPath, TEST_FILE_NAME)
e = checkFileReadability(fileToCheck)
if (e == null) {
sb.appendln("$fileToCheck is accessible.").appendln()
} else {
sb.appendln(e.message)
try {
sb.appendln("Trying to create $fileToCheck")
fileToCheck.createNewFile()
sb.appendln("Created $fileToCheck")
e = checkFileReadability(fileToCheck)
if (e == null) {
sb.appendln("$fileToCheck is accessible").appendln()
} else {
sb.appendln("e").appendln()
}
} catch (e: Exception) {
sb.appendln("Could not create $fileToCheck").appendln(e).appendln()
}
}
}
if (!myObbFile.exists()) {
sb.appendln("OBB file doesn't exist: $myObbFile").appendln()
obbDumpText.text = sb.toString()
return
}
e = checkFileReadability(myObbFile)
if (e != null) {
// Need to request READ_EXTERNAL_STORAGE permission before reading OBB file
sb.appendln("Need READ_EXTERNAL_STORAGE permission.").appendln()
obbDumpText.text = sb.toString()
return
}
sb.appendln("OBB is accessible at")
.appendln(myObbFile).appendln()
mStorageManager = getSystemService(Context.STORAGE_SERVICE) as StorageManager
obbDumpText.text = sb.toString()
}
private fun dumpMountedObb(obbMountPath: String) {
val obbFile = File(obbMountPath)
val sb = StringBuilder().appendln("Dumping OBB...").appendln()
sb.appendln("OBB file path is $myObbFile").appendln()
sb.appendln("OBB mounted at $obbMountPath").appendln()
val listFiles = obbFile.listFiles()
if (listFiles == null || listFiles.isEmpty()) {
Log.d(TAG, "No files in obb!")
return
}
sb.appendln("Contents of OBB").appendln()
for (listFile in listFiles) {
val zipFile = ZipFile(listFile)
sb.appendln("${listFile.name} has ${zipFile.entries().toList().size} entries.")
.appendln()
}
obbDumpText.text = sb.toString()
}
private fun checkFileReadability(file: File): Exception? {
if (!file.exists()) {
return IOException("$file does not exist")
}
var inputStream: FileInputStream? = null
try {
inputStream = FileInputStream(file).also { input ->
input.read()
}
} catch (e: IOException) {
return e
} finally {
inputStream?.close()
}
return null
}
fun onClick(view: View) {
mStorageManager.mountObb(
myObbFile.absolutePath,
null,
object : OnObbStateChangeListener() {
override fun onObbStateChange(path: String, state: Int) {
super.onObbStateChange(path, state)
val mountPath = mStorageManager.getMountedObbPath(myObbFile.absolutePath)
dumpMountedObb(mountPath)
}
}
)
}
companion object {
const val BLOB_FILE_NAME = "main.314159.com.example.opaquebinaryblob.obb"
const val TEST_FILE_NAME = "TestFile.txt"
const val TAG = "MainActivity"
}
}
activity_main.xml
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="16dp"
tools:context=".MainActivity">
<TextView
android:id="#+id/obbDumpText"
android:layout_width="0dp"
android:layout_height="0dp"
android:scrollbars="vertical"
android:text="Click the button to view content of the OBB."
android:textColor="#android:color/black"
app:layout_constraintBottom_toTopOf="#+id/dumpMountObb"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="spread_inside" />
<Button
android:id="#+id/dumpMountObb"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="onClick"
android:text="Dump\nMounted OBB"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/obbDumpText"
app:layout_constraintVertical_bias="0.79" />
</androidx.constraintlayout.widget.ConstraintLayout>
For a follow-up as stated here:
Since Android 4.4 (API level 19), apps can read OBB expansion files without external storage permission. However, some implementations of Android 6.0 (API level 23) and later still require permission, so you will need to declare the READ_EXTERNAL_STORAGE permission in the app manifest and ask for permission at runtime...
Does this apply to Android Q? It is not clear. The demo shows that it does not for the emulator. I hope that this is something that will be consistent across devices.

Downloading file and saving it to download folder using kotlin in Android

I am trying to download an apk file from the web server and store it in the download folder. I am using fuel library
Fuel.download("https://mypath/app.apk").destination {
response, url -> val dir = File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString()) File(dir, "abcd.apk")
}.progress {
readBytes, totalBytes -> val progress = readBytes.toFloat() / totalBytes.toFloat()
Log.d("log",progress.toString())
}.response {
req, res, result -> Log.d("log","download completed ")
Log.d("log",Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString() + "/abcd.apk")
}
I am getting bytesArray in response but the file is not saving to download folder. I have write_external_storage on my Manifest file. Please let me know what am I missing?

As you mentioned in comment that you are using targetSdkVersion as 23. Beginning with Android 6.0 (API level 23), if you set targetSdkVersion as 23 in your app you have to implement rumtime permission in your app.
To implement it please refer official documentation here Requesting Permissions at Run Time

fun storeImage(link: String) : String {
val policy: StrictMode.ThreadPolicy = StrictMode.ThreadPolicy.Builder().permitAll().build()
StrictMode.setThreadPolicy(policy)
val cw = ContextWrapper(applicationContext)
val directory: File = cw.getDir("imageDir", Context.MODE_PRIVATE)
val pictureFile = File(directory, "backgroundImage.gif")
URL(link).openStream().use { input ->
FileOutputStream(pictureFile).use { output ->
input.copyTo(output)
Log.e("DD GIF", "storeImage: FILE SAVED" )
return "SAVED"
}
}
}
it is working for me.