suspend fun copy(oldFile: File, newFile: File): Boolean{
return withContext(Dispatchers.IO) {
var inputStream: InputStream? = null
var outputStream: OutputStream? = null
try {
val fileReader = ByteArray(4096)
inputStream = oldFile.inputStream()
outputStream = FileOutputStream(newFile)
while (true) {
val read: Int = inputStream.read(fileReader)
if (read == -1) {
break
}
outputStream.write(fileReader, 0, read)
}
outputStream.flush()
true
} catch (e: IOException) {
Log.e(TAG, "${e.message}")
false
} finally {
inputStream?.close()
outputStream?.close()
}
}
}
In the above code, if I cancel the job that is running the function, does the copying gets cancelled or do I have to manually check for state of the job inside while loop using ensureActive()?
Related
I wrote an App, in Kotlin with Android Studio that write some strings to a file.
All work, I can write and read inside the App, but I can't see the file looking in Documents folder.
How can I use the folder Documents as a storage space?
Thank you
These are the function I use:
fun saveTextFile(view: View, nomeFile: String, testo: String, contesto: Context){
var fileStream: FileOutputStream
try {
fileStream = contesto.openFileOutput(nomeFile, MODE_APPEND) // OK esegue append
fileStream.write(testo.toByteArray())
fileStream.close()
}catch (e: Exception){
e.printStackTrace()
}
}
fun readTextFile(view: View, nomeFile: String, contesto: Context): String{
var fileInputStream: FileInputStream? = null
fileInputStream = contesto.openFileInput(nomeFile)
var inputStreamReader: InputStreamReader = InputStreamReader(fileInputStream)
val bufferedReader: BufferedReader = BufferedReader(inputStreamReader)
val stringBuilder: StringBuilder = StringBuilder()
var text: String? = null
while ({ text = bufferedReader.readLine(); text }() != null) {
stringBuilder.append(text)
}
inputStreamReader.close();
return(stringBuilder.toString())
}
Thank you, Livio
For writing in Documents folder of your device , you just need to make use of MediaStore for the same. You can take input for this function anything that you want like String , bitmap , PdfDocument and other's too .
For Your UseCase you can do the following ,
Global Variable :
private var imageUri: Uri? = null
override suspend fun saveDocument(context : Context, text : String) {
withContext(Dispatchers.IO) {
try {
val collection =
MediaStore.Files.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val dirDest = File(
Environment.DIRECTORY_DOCUMENTS,
context.getString(R.string.app_name)
)
val date = System.currentTimeMillis()
val fileName = "$date.txt"
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, fileName)
put(MediaStore.MediaColumns.RELATIVE_PATH,
"$dirDest${File.separator}")
put(MediaStore.Files.FileColumns.IS_PENDING, 1)
}
}
val imageUri = context.contentResolver.insert(collection, contentValues)
withContext(Dispatchers.IO) {
imageUri?.let { uri ->
context.contentResolver.openOutputStream(uri, "w").use { out -> out?.write(text.toByteArray())
}
contentValues.clear()
contentValues.put(MediaStore.Files.FileColumns.IS_PENDING, 0)
context.contentResolver.update(uri, contentValues, null, null)
}
}
} catch (e: FileNotFoundException) {
null
}
}
}
For Updating the already existing file , do the following . After creating file for the first time I have saved the imageUri in a global variable (If you want to store it permanently / or for a while you can use Jetpack Datastore / Shared Preference to save the same ):
suspend fun updateData(context: Context,text : String){
withContext(Dispatchers.IO) {
try {
val collection =
MediaStore.Files.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val dirDest = File(
Environment.DIRECTORY_DOCUMENTS,
context.getString(R.string.app_name)
)
val fileName = "test.txt"
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, fileName)
put(
MediaStore.MediaColumns.RELATIVE_PATH,
"$dirDest${File.separator}"
)
put(MediaStore.Files.FileColumns.IS_PENDING, 1)
}
withContext(Dispatchers.IO) {
imageUri?.let { uri ->
context.contentResolver.openOutputStream(uri, "wa").use { out ->
out?.write(text.toByteArray())
}
contentValues.clear()
contentValues.put(MediaStore.Files.FileColumns.IS_PENDING, 0)
context.contentResolver.update(uri, contentValues, null, null)
}
}
} catch (e: FileNotFoundException) {
null
}
}
}
For Reading the File , Do the following :
suspend fun read(context: Context, source: Uri): String = withContext(Dispatchers.IO) {
val resolver: ContentResolver = context.contentResolver
resolver.openInputStream(source)?.use { stream -> stream.readText() }
?: throw IllegalStateException("could not open $source")
}
private fun InputStream.readText(charset: Charset = Charsets.UTF_8): String =
readBytes().toString(charset)
This is how the final code looks like :
class MainActivity : AppCompatActivity() {
private lateinit var btn: Button
private var imageUri: Uri? = null
private lateinit var btn2: Button
private lateinit var btn3 : Button
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
btn = findViewById(R.id.btnAdd)
btn2 = findViewById(R.id.getText)
btn3 = findViewById(R.id.updateText)
btn.setOnClickListener {
lifecycleScope.launch {
saveDocument(applicationContext, "Original ")
}
}
btn3.setOnClickListener {
lifecycleScope.launch {
updateData(applicationContext,"Appended")
}
}
btn2.setOnClickListener {
lifecycleScope.launch {
imageUri?.let { it1 ->
val data = read(applicationContext, it1)
Toast.makeText(applicationContext, "The data is $data ", Toast.LENGTH_LONG)
.show()
}
}
}
}
suspend fun saveDocument(context: Context, text: String) {
withContext(Dispatchers.IO) {
try {
val collection =
MediaStore.Files.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val dirDest = File(
Environment.DIRECTORY_DOCUMENTS,
context.getString(R.string.app_name)
)
val date = System.currentTimeMillis()
val fileName = "test.txt"
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, fileName)
put(
MediaStore.MediaColumns.RELATIVE_PATH,
"$dirDest${File.separator}"
)
put(MediaStore.Files.FileColumns.IS_PENDING, 1)
}
imageUri = context.contentResolver.insert(collection, contentValues)
withContext(Dispatchers.IO) {
imageUri?.let { uri ->
context.contentResolver.openOutputStream(uri, "w").use { out ->
out?.write(text.toByteArray())
}
contentValues.clear()
contentValues.put(MediaStore.Files.FileColumns.IS_PENDING, 0)
context.contentResolver.update(uri, contentValues, null, null)
}
}
} catch (e: FileNotFoundException) {
null
}
}
}
suspend fun updateData(context: Context, text: String) {
withContext(Dispatchers.IO) {
try {
val collection =
MediaStore.Files.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val dirDest = File(
Environment.DIRECTORY_DOCUMENTS,
context.getString(R.string.app_name)
)
val fileName = "test.txt"
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, fileName)
put(
MediaStore.MediaColumns.RELATIVE_PATH,
"$dirDest${File.separator}"
)
put(MediaStore.Files.FileColumns.IS_PENDING, 1)
}
withContext(Dispatchers.IO) {
imageUri?.let { uri ->
context.contentResolver.openOutputStream(uri, "wa").use { out ->
out?.write(text.toByteArray())
}
contentValues.clear()
contentValues.put(MediaStore.Files.FileColumns.IS_PENDING, 0)
context.contentResolver.update(uri, contentValues, null, null)
}
}
} catch (e: FileNotFoundException) {
null
}
}
}
suspend fun read(context: Context, source: Uri): String = withContext(Dispatchers.IO) {
val resolver: ContentResolver = context.contentResolver
resolver.openInputStream(source)?.use { stream -> stream.readText() }
?: throw IllegalStateException("could not open $source")
}
private fun InputStream.readText(charset: Charset = Charsets.UTF_8): String =
readBytes().toString(charset)
I have three buttons . With the first I create a file , then the uri gets stored in the global variable . Then onClick of second button I add to the already existing file and then read the file using the third button using the same imageUri stored in the global variable
This is the demo for the same . Check when the buttons are being pressed and the output in the form of Toast at the bottom .
I am working on Bluetooth receiving and sending data. I can send data via Bluetooth but it doesn't work the receive data. I want to get string data and split it. And the split data will show the list view. Since data import is not working, I created string data and called the split method, but it didn't work here either in a release. Can you help me?
Here are my Activity codes;
var mUUID: UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB")
var mBluetoothSocket: BluetoothSocket? = null
lateinit var mProgress: ProgressDialog
lateinit var mBluetoothAdapter: BluetoothAdapter
var mIsConnected: Boolean = false
lateinit var mAddress: String
lateinit var inputStream: InputStream
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityListBinding.inflate(layoutInflater)
val view = binding.root
setContentView(view)
mAddress = intent.getStringExtra(MainActivity.EXTRA_ADDRESS).toString()
ConnectToDevice(this).execute()
run()
binding.deneme.setOnClickListener {
sendCommand("denemebeyza")
Log.d("mesajBT", "onCreate: mesaj gonderildi")
}
val string2: String = "deneme, deneme02K, deneme90,klm08B,bitti."
splitList(string2)
}
private fun sendCommand(input: String) {
if (mBluetoothSocket != null) {
try {
mBluetoothSocket!!.outputStream.write(input.toByteArray())
} catch (e: IOException) {
e.printStackTrace()
}
}
}
fun run() {
val LOGTAG: String ="ReadListString"
Log.i(LOGTAG, Thread.currentThread().name)
val buffer = ByteArray(8)
var bytes: Int
val text1: TextView = binding.text2
var readText : String
Log.d("mesajBt", "mesaj metodu")
//Loop to listen for received bluetooth messages
if (mBluetoothSocket != null) {
while (true) {
bytes = try {
bytes = inputStream.read(buffer) ?:0
readText = String(buffer, 0, bytes)
Log.e("Arduino Message", readText)
} catch (e: IOException) {
e.printStackTrace()
Log.d("Else", "message alinamadi.")
break
}
text1.text =readText
}
}
}
fun splitList(output: String) {
val listView : ListView= binding.list1
val textView: TextView= binding.text1
if (mBluetoothSocket != null) {
try {
val list: List<String> = output.split(",").toList()
var arrayAdapter: ArrayAdapter<*>
for (it in list) {
Log.e("TAG", "splitList: $list ")
val list2: ArrayList<String> = ArrayList(list)
textView.text = list2.toString()
}
arrayAdapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, list)
listView.adapter=arrayAdapter
} catch (e: IOException) {
e.printStackTrace()
}
// [A, B, C, D]
}
}
private class ConnectToDevice(c: Context) : AsyncTask<Void, Void, String>() {
private var connectSuccess: Boolean = true
#SuppressLint("StaticFieldLeak")
val context: Context = c
#Deprecated("Deprecated in Java")
override fun onPreExecute() {
super.onPreExecute()
mProgress = ProgressDialog.show(
context,
context.getString(R.string.connecting),
context.getString(R.string.connecting)
)
}
#SuppressLint("MissingPermission")
override fun doInBackground(vararg p0: Void?): String? {
try {
if (mBluetoothSocket == null || !mIsConnected) {
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter()
val device: BluetoothDevice = mBluetoothAdapter.getRemoteDevice(mAddress)
mBluetoothSocket = device.createInsecureRfcommSocketToServiceRecord(mUUID)
BluetoothAdapter.getDefaultAdapter().cancelDiscovery()
mBluetoothSocket!!.connect()
inputStream = mBluetoothSocket!!.inputStream
}
}catch (e: IOException) {
connectSuccess = false
e.printStackTrace()
}
return null
}
override fun onPostExecute(result: String?) {
super.onPostExecute(result)
if (!connectSuccess) {
Log.i("data", "couldn't connect")
} else {
mIsConnected = true
}
mProgress.dismiss()
}
}
}
Here is debugged console log.e output
Thanks, advance :)
I/ReadList-run: main
E/mesajBt: mesaj metodu
W/BluetoothAdapter:getBluetoothService() called with no BluetoothManagerCallback
W/libEGL: EGLNativeWindowType 0xc9a7d808 disconnect failed
W/libEGL:EGLNativeWindowType 0xc95be008 disconnect failed
I/InputMethodManager: startInputInner mService.startInputOrWindowGainedFocus E/ViewRootImpl:sendUserActionEvent() returned.
I/InputMethodManager: startInputInner - mService.startInputOrWindowGainedFocus
Since there will be commas between words in data coming from Bluetooth, I used a comma as a separator in the split method. After some research, I corrected a few mistakes. You can change the value of the bytes as 8-16-32-64 according to the incoming data type and size.
Receive method is here
private fun run() {
//Loop to listen for received bluetooth messages
if (mBluetoothSocket != null) {
val TAG: String = "ReadList-run"
Log.i(TAG, Thread.currentThread().name)
val buffer = ByteArray(1024)
var bytes: Int
var readText: String
Log.e("mesajBt", "mesaj metodu")
while (true) {
try {
bytes = inputStream.read(buffer)
readText = String(buffer, 0, bytes)
Log.e("Arduino Message", readText)
splitlist(readText)
break
} catch (e: IOException) {
e.printStackTrace()
Log.d("Else", "message alinamadi.")
break
}
}
}
}
Here is my split method
fun splitList(output: String) {
if (mBluetoothSocket != null) {
try {
val list: List<String> = output.split(",").toList()
for (it in list) {
Log.e("TAG", "splitList: $list ")
}
} catch (e: IOException) {
e.printStackTrace()
}
// [A, B, C, D]
}
}
Will the following code leak resources when the Kotlin coroutine is canceled?
General: The code is nested inside a ViewModel!
The method retrievePDFDocument will get triggered in the onStart Event of a Fragment.
fun retrievePDFDocument() {
job = viewModelScope.launch {
withContext(Dispatchers.IO) {
downloadFile(assetPath.value!!)
}
}
}
And here the suspend function:
private fun downloadFile(strPdfUrl: String): File? {
var inputStream: InputStream? = null
val lenghtOfFile: Int //lenghtOfFile is used for calculating download progress
//this is where the file will be seen after the download
var fileOut: FileOutputStream? = null
var localPDFFile: File? = null
if(strPdfUrl.isBlank())
return localPDFFile
try {
val pdfUrl = URL(strPdfUrl)
val urlConnection = pdfUrl.openConnection() as HttpURLConnection
if (urlConnection.responseCode == 200) {
//file input is from the url
inputStream = BufferedInputStream(urlConnection.inputStream)
lenghtOfFile = urlConnection.contentLength
localPDFFile = File(localPdfDirectory, pdfFileName.value!!)
fileOut = FileOutputStream(localPDFFile)
//here’s the download code
val buffer = ByteArray(1024)
var total: Long = 0
while (true) {
// If coroutine is cancelled
// a CancellationException will be thrown here
// Do not more work then necesarry
coroutineContext.ensureActive()
val length = inputStream.read(buffer)
if (length <= 0) break
total += length.toLong()
_currProgress.postValue( (total * 100 / lenghtOfFile).toInt() )
fileOut.write(buffer, 0, length)
}
}
} catch (e: IOException) {
Log.e("PdfViewerViewModel - downloadFile Error: ${e.message}")
localPdfFile?.delete() // remove partially downloaded file
localPDFFile = null
} catch (e1: CancellationException) {
Log.e("PdfViewerViewModel - downloadFile CancellationException: ${e1.message}")
localPdfFile?.delete() // remove partially downloaded file
localPdfFile = null
finally {
try {
inputStream?.close()
fileOut?.apply {
flush()
close()
}
} catch (e1: IOException) { //do nothing here }
}
return localPDFFile
}
Kindly regards
Frank
#Update 10.04.2020
Implementation with coroutineContext.ensureActive() and catching the exception
The traditional approach in Java to execute an external process is to start a new Process, start two threads to consume its inputStream and errorStream and then call its blocking Process.waitFor() to wait till the external command has exited.
How can this be done in a (almost) non-blocking style with Kotlin coroutines?
I tried it this way. Do you have any suggestions to improve it?
(How to asynchronously read the streams, also call ProcessBuilder.start() in withContext(Dispatchers.IO), are there too many calls to Dispatchers.IO, ...?)
suspend fun executeCommand(commandArgs: List<String>): ExecuteCommandResult {
try {
val process = ProcessBuilder(commandArgs).start()
val outputStream = GlobalScope.async(Dispatchers.IO) { readStream(process.inputStream) }
val errorStream = GlobalScope.async(Dispatchers.IO) { readStream(process.errorStream) }
val exitCode = withContext(Dispatchers.IO) {
process.waitFor()
}
return ExecuteCommandResult(exitCode, outputStream.await(), errorStream.await())
} catch (e: Exception) {
return ExecuteCommandResult(-1, "", e.localizedMessage)
}
}
private suspend fun readStream(inputStream: InputStream): String {
val readLines = mutableListOf<String>()
withContext(Dispatchers.IO) {
try {
inputStream.bufferedReader().use { reader ->
var line: String?
do {
line = reader.readLine()
if (line != null) {
readLines.add(line)
}
} while (line != null)
}
} catch (e: Exception) {
// ..
}
}
return readLines.joinToString(System.lineSeparator())
}
I have 2 requests: SIGNUP and SIGNUP_UPLOAD_AVATAR
#POST(SIGNUP)
fun registerUser(#QueryMap(encoded = true) userCredentials: HashMap<String, Any>): Deferred<Response<UserResponse>>
#Multipart
#POST(SIGNUP_UPLOAD_AVATAR) //SHOULD BE A PUT, DUE TO ONLY SEND FILE.
fun uploadAvatar(#Part file: MultipartBody.Part): Deferred<Response<ResponseBody>>
currently i decided to change for the use of COROUTINES however im having an issue, that is when the first post SIGNUP_UPLOAD_AVATAR start his request, i need to wait till it finish to go with the SIGNUP process. However the second coroutine start immediately, without asking if the first request finish or is still working.
This is my function:
fun getImageUrlCoRoutine(){
val requestFile = RequestBody.create(MediaType.parse("multipart/form-data"), profilePicture)
val body = MultipartBody.Part.createFormData("file", "android.${getFileExtension(profilePicture)}", requestFile)
val service = APIService.create()
val request = service.uploadAvatar(body)
try {
GlobalScope.launch(Dispatchers.Main) {
val response = CoroutineUtil().retryIO (times = 3){ request.await() }
val responseCode = StatusCode(response.code()).description
when(responseCode){
StatusCode.Status.OK -> {
response.body()?.let {
it.let {
println("RESULT: " + it.string())
avatarUrl = it.string()
println("Avatar: " + avatarUrl)
registrationCoroutine(this) <- here goes for the second request(registration)
}
}
}
else -> {}
}
}
}catch (e: HttpException){
val responseCode = StatusCode(e.code()).description
when(responseCode){
StatusCode.Status.NotAcceptable -> {
}
else -> {
}
}
}catch (e: Throwable){
println("Houston we got a Coroutine Problem")
println(e)
}
}
fun registrationCoroutine(suspended: CoroutineScope) {
val service = APIService.create()
val data = HashMap<String, Any>()
data["email"] = email
data["phone"] = phoneNumber
data["username"] = email
data["password"] = password
data["fullName"] = fullname
data["token"] = ""
data["appName"] = BuildConfig.APP_NAME
data["avatarUrl"] = avatarUrl
data["deviceType"] = BuildConfig.PLATFORM
data["needsVerify"] = false
suspended.launch {
val request = service.registerUser(data)
try {
val response = CoroutineUtil().retryIO(times = 3) { request.await() }
val responseCode = StatusCode(response.code()).description
when(responseCode){
StatusCode.Status.OK -> {
response.body()?.let {
it.let {
println(it)
}
}
}
else -> {}
}
} catch (e: HttpException) {
val responseCode = StatusCode(e.code()).description
when(responseCode){
StatusCode.Status.NotAcceptable -> {}
else -> {}
}
} catch (e: Throwable) {
println("Houston we have a coroutine problem")
println(e)
}
}
}
and the responses that i get...
2019-06-25 08:41:28.858 19886-19886/com.multirequest.development
I/System.out: RESULT:
2019-06-25 08:41:28.859 19886-19886/com.multirequest.development
I/System.out: Avatar:
2019-06-25 08:41:28.880 19886-20735/com.multirequest.development
D/OkHttp: --> POST
http://myCustomURL.com/signup?deviceType=ANDROID&password=demdemdem&needsVerify=false&phone=+1123456789&avatarUrl=&appName=DEMO&fullName=demmmm&email=demm#gmail.com&username=demm#gmail.com&token=
201
And i need that when i get the AvatarURL the signup process begin...
Thanks :)