Develop Reference

Android rename file successful but file is deleted

I want rename file and when use bellow code and rename file successful but after I don't see that file on my phone and the file is deleted. I requested 2 permissions READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE successful
My code to get all image in device and rename function
MainActivity{
getAllImages()
btn_rename.setOnClickListener{
var old_file=listImageFile.get(pos_selected)
var new_file=File(old_file.parent,new_name)
var check:Boolean=old_file.renameTo(new_file)
if(check){
// check return true
}
}
}
fun getAllImages() {
listImageFile= arrayListOf()
val allImages = arrayListOf<Uri>()
val imageProjection = arrayOf(
MediaStore.Images.Media.DATA,
)
val cursor = requireActivity().contentResolver.query(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
imageProjection,
null,
null
)
cursor.use {
if (cursor != null) {
val data = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA)
while (cursor.moveToNext()) {
var path = cursor.getString(data)
var file=File(path)
if(file.exists()){
listImageFile.add(
FileData(
file,
false
)
)
}
}
}
}
}

Whenever you create/rename/delete file, you must refresh the system files.
Try this below solution after rename the file:
btn_rename.setOnClickListener{
var old_file=listImageFile.get(pos_selected)
var new_file=File(old_file.parent,new_name)
var check:Boolean=old_file.renameTo(new_file)
if(check){
// check return true
MediaScannerConnection.scanFile(context, arrayOf(old_file.absolutePath),null,null)
MediaScannerConnection.scanFile(context, arrayOf(new_file.absolutePath),null,null)
}
}

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

File found using android MediaStore but BitmapFactory unable to decode it with path returned from MediaStore

I have searched high and low and not found an answer to my particular question, I hope someone can help.
I am developing this for Android 9 and above, the code I use for older releases works fine.
It's quite simple, I have stored an image in the MediaStore, I have found the image in the media store, I return its path, I check the path exists and it does, it also has a correct size and is visible in the android Gallery. So why when I try to open it with
val bitmap2 = BitmapFactory.decodeFile(fullPath)
bitmap2 comes back as null - no errors are generated by the above command. The parseAllImages function was taken from the web and tweaked slightly but seems to work ok as far as I can tell.
sample code
private fun setPic() {
if (mediaPath.isNotEmpty()) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val content = GalleryAdd.parseAllImages(requireActivity(), mediaPath)
val fullPath = content
if (File(fullPath).exists()) {
val tester = File(fullPath).length()
val bitmap2 = BitmapFactory.decodeFile(fullPath)
viewModel.setBitmap(bitmap2)
}
}
}
}
fun parseAllImages(act : Activity, name : String) : String {
try {
val projection =
arrayOf(MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID)
val cursor = act.contentResolver.query(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
projection, // Which columns to return
null, // Return all rows
null,
null
)
val size: Int = cursor!!.getCount()
/******* If size is 0, there are no images on the SD Card. */
if (size == 0) {
} else {
val thumbID = 0
if (cursor != null) {
while (cursor.moveToNext()) {
val file_ColumnIndex: Int =
cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA)
/**************** Captured image details */
/***** Used to show image on view in LoadImagesFromSDCard class */
val idColumn = cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID)
val path: String = cursor.getString(file_ColumnIndex)
val fileName =
path.substring(path.lastIndexOf("/") + 1, path.length)
if (fileName == name)
{
return path
}
}
}
}
} catch (e: Exception) {
e.printStackTrace()
}
return ""
}
Code snippet I use to write to the media store
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val resolver: ContentResolver = activity.contentResolver
val contentValues = ContentValues()
contentValues.put(
MediaStore.MediaColumns.DISPLAY_NAME,
fileName
)
contentValues.put(MediaStore.MediaColumns.MIME_TYPE, "image/jpg")
contentValues.put(
MediaStore.MediaColumns.RELATIVE_PATH,
Environment.DIRECTORY_PICTURES + File.separator + "fishy"
)
val imageUri: Uri? =
resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, contentValues)
val tester = imageUri.toString() + File.separator + Environment.DIRECTORY_PICTURES + File.separator + "fishy" + File.separator + fileName
scanLoc = fileName
fos = resolver.openOutputStream(imageUri!!)!!
val file = File(currentPhotoPath)
val ins: InputStream = file.inputStream()
ins.copyTo(fos)
}
Any help or can someone point me to sample code that can read a jpg image from the mediastore given it's name? It's not production ready so please forgive lack of error checks.
Thanks
Lee.

Getting list of images from a folder in android kotlin

I'm trying to get list of images from a folder using this function
var gpath:String = Environment.getExternalStorageDirectory().absolutePath
var spath = "testfolder"
var fullpath = File(gpath + File.separator + spath)
var list = imageReader(fullpath)
fun imageReader(root : File):ArrayList<File>{
val a : ArrayList<File> ? = null
val files = root.listFiles()
for (i in 0..files.size){
if (files[i].name.endsWith(".jpg")){
a?.add(files[i])
}
}
return a!!
}
but i have these exceptions :
java.lang.ArrayIndexOutOfBoundsException:length=3;index=3
kotin.kotlinNullPointerException
I've read about this problem but i have no idea how to fix it,
any help please?

For Null Pointer you may need to change and pass fullpath instead of path inside var list = imageReader(path).
Wrong
var fullpath = File(gpath + File.separator + spath)
var list = imageReader(path)
Right
var gpath:String = Environment.getExternalStorageDirectory().absolutePath
var spath = "testfolder"
var fullpath = File(gpath + File.separator + spath)
var list = imageReader(fullpath)
EDIT 1
I have made few changes to function and apply it inside override fun onCreate as below.
var gpath: String = Environment.getExternalStorageDirectory().absolutePath
var spath = "Download"
var fullpath = File(gpath + File.separator + spath)
Log.w("fullpath", "" + fullpath)
imageReaderNew(fullpath)
Function
fun imageReaderNew(root: File) {
val fileList: ArrayList<File> = ArrayList()
val listAllFiles = root.listFiles()
if (listAllFiles != null && listAllFiles.size > 0) {
for (currentFile in listAllFiles) {
if (currentFile.name.endsWith(".jpeg")) {
// File absolute path
Log.e("downloadFilePath", currentFile.getAbsolutePath())
// File Name
Log.e("downloadFileName", currentFile.getName())
fileList.add(currentFile.absoluteFile)
}
}
Log.w("fileList", "" + fileList.size)
}
}
Logcat Output
W/fullpath: /storage/emulated/0/Download
E/downloadFilePath: /storage/emulated/0/Download/download.jpeg
E/downloadFileName: download.jpeg
E/downloadFilePath: /storage/emulated/0/Download/images.jpeg
E/downloadFileName: images.jpeg
E/downloadFilePath: /storage/emulated/0/Download/images (1).jpeg
E/downloadFileName: images (1).jpeg

fun imageReader(root : File):ArrayList<File>{
val a : ArrayList<File> ? = null
val files = root.listFiles()
for (i in 0..files.size-1){
if (files[i].name.endsWith(".jpg")){
a?.add(files[i])
}
}
return a!!
}

The above answer is right but it declares a as null and then in loop uses null save. Therefore it detects images but does not add them to the list and the list returns null.
fun imageReader(root: File): ArrayList < File > {
val a: ArrayList < File > = ArrayList()
if (root.exists()) {
val files = root.listFiles()
if (files.isNotEmpty()) {
for (i in 0..files.size - 1) {
if (files[i].name.endsWith(".jpg")) {
a.add(files[i])
}
}
}
}
return a!!
}

By using MediaStore we can achieve count of image inside a folder and we will add one more check to prevent getting image of subfolders of current folder.
fun getImageCountInDirectory(context: Context, directoryPath: String): Int {
var imageCount = 0
val uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
val sortOrder = MediaStore.Images.Media.DATE_MODIFIED + " DESC"
val selection = "${MediaStore.Images.Media.DATA} like ? and ${MediaStore.Images.Media.DATA} not like ?"
val selectionArgs = arrayOf("$directoryPath/%", "$directoryPath/%/%") // use % as a wildcard character to select all files inside the directory, and exclude subdirectories
val cursor = context.contentResolver.query(
uri,
null,
selection,
selectionArgs,
sortOrder
)
if (cursor != null) {
imageCount = cursor.count
cursor.close()
}
return imageCount
}
This function will return an integer value and it is the total number of image files inside the folder. And we are using the not like operator and adding %/% to the selectionArgs array to select all files whose path doesn't contain a subdirectory.

Android: Read a file without external storage permission

I don't want my app to require any permissions, but I want the user to be able to select a file for reading. My app doesn't need arbitrary access to the filesystem. However, all openfiledialog implementations I have researched so far seem to assume permission to access external storage.
One workaround I can think of is to configure my app to be among the list of apps to open a certain type of file. I haven't tried this, but I hope this would work without permission to access external storage. However, user guidance would be less then ideal in this case. I would prefer a solution with a dialog and have the user pick the file.
I think this requirement does not undermine security, because the user has full control over the file my app can read. Is this possible somehow?

However, all openfiledialog implementations I have researched so far seem to assume permission to access external storage.
Set your minSdkVersion to 19, then use ACTION_OPEN_DOCUMENT, part of the Storage Access Framework.
Or, if you need your minSdKVersion to be below 19, use ACTION_GET_CONTENT on the older devices.
You will get a Uri back via onActivityResult(). Use a ContentResolver and methods like openInputStream() to consume the content identified by that Uri.
I haven't tried this, but I hope this would work without permission to access external storage
Only if you exclude file: Uri values. For example, an <intent-filter> that supports only content: Uri values would work.

Android 11 Resolve file access issue without use of MANAGE_EXTERNAL_STORAGE.
I have added code for get doc file and Upload to server.
AndroidManifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application
android:preserveLegacyExternalStorage="true"
android:requestLegacyExternalStorage="true"
</application>
Now, Add this lib in your project
https://github.com/FivesoftCode/FilePicker
Add below code to Activity/Fragment
FilePicker.from(activity)
.setFileTypes(FilePicker.IMAGE, FilePicker.VIDEO) //Set file types you want to pick.
.setAllowMultipleFiles(true) //Allow user to select multiple files
.setListener { files -> //Wait for results
if (files != null && files.size > 0) {
//Do something with uris.
for (items in files) {
val extension: String = getMimeType(activity!!,items)!!
if (extension == "pdf") {
val cacheDir: String = context!!.cacheDir.toString()
val getCopyFilePath = copyFileToInternalStorage(context!!,items,cacheDir)
Log.e("TAG", "getPathToUploadDoc: " + getCopyFilePath )
}
}
} else {
//Add msg here...
}
}
.setTitle("Pick a file from My Files")
.pick() //Open file picker
Add below method for get Mime Type
fun getMimeType(context: Context, uri: Uri): String? {
val extension: String?
//Check uri format to avoid null
extension = if (uri.scheme == ContentResolver.SCHEME_CONTENT) {
//If scheme is a content
val mime = MimeTypeMap.getSingleton()
mime.getExtensionFromMimeType(context.contentResolver.getType(uri))
} else {
//If scheme is a File
//This will replace white spaces with %20 and also other special characters. This will avoid returning null values on file name with spaces and special characters.
MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(File(uri.path)).toString())
}
return extension
}
fun getFiledetails(uri: Uri,context: Context,getCopyFilePath:String): NormalFile? {
// var result: String? = null
if (uri.scheme == "content") {
val cursor: Cursor = context.contentResolver.query(uri,
FileLoader.FILE_PROJECTION, null, null, null)!!
try {
if (cursor != null && cursor.moveToFirst()) {
// result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME))
val path: String = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA))
if (path != null && path != "") {
//Create a File instance
cursor.getLong(cursor.getColumnIndexOrThrow(BaseColumns._ID))
// cursor.getLong(cursor.getColumnIndexOrThrow(BaseColumns._ID)).toInt()
cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.TITLE))
// cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA))
cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.SIZE))
cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATE_ADDED))
cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.MIME_TYPE))
}
}
} finally {
cursor.close()
}
}
/*if (result == null) {
result = uri.path
val cut = result!!.lastIndexOf('/')
if (cut != -1) {
result = result.substring(cut + 1)
}
}*/
return file
}
fun copyFileToInternalStorage(context: Context?,uri: Uri, newDirName: String): String? {
val returnCursor = context!!.contentResolver.query(
uri, arrayOf(
OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE
), null, null, null
)
/*
* Get the column indexes of the data in the Cursor,
* * move to the first row in the Cursor, get the data,
* * and display it.
* */
val nameIndex = returnCursor!!.getColumnIndex(OpenableColumns.DISPLAY_NAME)
val sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE)
returnCursor.moveToFirst()
val name = returnCursor.getString(nameIndex)
val size = java.lang.Long.toString(returnCursor.getLong(sizeIndex))
val output: File
output = if (newDirName != "") {
val dir = File(/*context!!.filesDir.toString() + "/" +*/ newDirName)
if (!dir.exists()) {
dir.mkdir()
}
File(/*context!!.filesDir.toString() + "/" +*/ newDirName + "/" + name)
} else {
File(context!!.filesDir.toString() + "/" + name)
}
try {
val inputStream: InputStream? = context!!.contentResolver.openInputStream(uri)
val outputStream = FileOutputStream(output)
var read = 0
val bufferSize = 1024
val buffers = ByteArray(bufferSize)
while (inputStream?.read(buffers).also { read = it!! } != -1) {
outputStream.write(buffers, 0, read)
}
inputStream?.close()
outputStream.close()
} catch (e: Exception) {
Log.e("Exception", e.message!!)
}
return output.path
}
For upload Doc
implementation 'net.gotev:uploadservice:2.1'
var uploadId = UUID.randomUUID().toString()
val url = ServerConfig.MAIN_URL
uploadReceiver.setDelegate(this)
uploadReceiver.setUploadID(uploadId)
val data = MultipartUploadRequest(mContext, uploadId, url)
.addFileToUpload(path, "attachment")
.addHeader("Authentication", getMD5EncryptedString())
.addParameter(USER_ID,1)
.setMaxRetries(5)
.startUpload()
fun getMD5EncryptedString(): String {
val encTarget = ServerConfig.AUTHENTICATE_VALUE //Any pwd
var mdEnc: MessageDigest? = null
try {
mdEnc = MessageDigest.getInstance("MD5")
} catch (e: NoSuchAlgorithmException) {
println("Exception while encrypting to md5")
e.printStackTrace()
}
mdEnc!!.update(encTarget.toByteArray(), 0, encTarget.length)
var md5 = BigInteger(1, mdEnc.digest()).toString(16)
while (md5.length < 32) {
md5 = "0$md5"
}
return md5
}