Develop Reference

ClassCast Error trying to read UploadTask$TaskSnapshot [duplicate]

I get the following error when trying to iterate over the uploadTasks inside an addOnSuccessListener method.
java.lang.ClassCastException: com.google.firebase.storage.UploadTask$TaskSnapshot cannot be cast to com.google.firebase.storage.UploadTask
So how can i get the Download String of each Img inside addOnSuccessListener?
val baos = ByteArrayOutputStream()
val tasks = mutableListOf<UploadTask>()
listImg.forEach {
if(bitmap!!.byteCount != it.byteCount) {
val bitmap = it
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos)
val data = baos.toByteArray()
var uploadTask = spaceRef.putBytes(data)
tasks.add(uploadTask)
}
}
Tasks.whenAllSuccess<UploadTask>(tasks).addOnSuccessListener { uploadTasks ->
//uploadTasks has size of 2
val urls = mutableListOf<Uri>()
lifecycleScope.launch
{
//Error throws here
uploadTasks.forEach{
urls.add(it.await().storage.downloadUrl.await())
}
}
}

The type of whenAllSuccess is <TResult>, so you should use the result type of UploadTask (UploadTask.TaskSnapshot) instead:
Tasks.whenAllSuccess<UploadTask.TaskSnapshot>(tasks).addOnSuccessListener { uploadTasks ->
And then you can drop the the first await() on that last line:
urls.add(it.storage.downloadUrl.await())
Bonus: Don't block the main thread
Note that Tasks.whenAllSuccess() will block the main thread until all uploads succeed, meaning your UI might freeze while uploading files.
To avoid that, consider uploading your files with Coroutines:
val baos = ByteArrayOutputStream()
val urls = mutableListOf<Uri>()
lifecycleScope.launch {
listImg.forEach {
if(bitmap!!.byteCount != it.byteCount) {
val bitmap = it
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos)
val data = baos.toByteArray()
// Upload the image first
val taskSnapshot = spaceRef.putBytes(data).await()
// Get the download Url
val downloadUri = taskSnapshot.storage.downloadUrl.await()
// Add it to the list of Uris
urls.add(downloadUri)
}
}
}

How to get the bmp extension files through the intent - Android kotlin

I want to pick the images with the extension "bmp" through the intent. I have tried passsing the "image/bmp" but it didn't worked. So what's the working way to get the "bmp" extension images through the intent.

Convert it into a string. First you need to convert the file to a .jpg or .png file, (you will have to do this manually outside of code), then convert to bitmap:
Bitmap bmp = BitmapFactory.decodeFile( PathToFileString );
or
Bitmap bmp = BitmapFactory.decodeFileDescriptor( fileDescriptorObject );
then
fun encode(imageUri: Uri): String {
val input = activity.getContentResolver().openInputStream(imageUri)
val image = BitmapFactory.decodeStream(input , null, null)
// Encode image to base64 string
val baos = ByteArrayOutputStream()
image.compress(Bitmap.CompressFormat.JPEG, 100, baos)
var imageBytes = baos.toByteArray()
val imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT)
return imageString
}
fun decode(imageString: String) {
// Decode base64 string to image
val imageBytes = Base64.decode(imageString, Base64.DEFAULT)
val decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0,
imageBytes.size)
imageview.setImageBitmap(decodedImage)
}
Once you have your string, then put it into an intent:
val intent = Intent(this, YourClass::class.java)
intent.putExtra("image", yourString);
startActivity(intent)

How could we pass a list of object between android phone and wear device?

In phone code, I use Serializable to transfer to ByteArray to be passed in an asset, wear(watch) is able to receive it but in the following code, payload doesn't contain any data that can be transferred back to original data.
var b = ListToPass(listOf("mission 1", "mission 2"))
this.dataMap.putAsset("KEY", Asset.createFromBytes(b.toByteArray()))
fun Serializable.toByteArray(): ByteArray {
val byteArrayOutputStream = ByteArrayOutputStream()
val objectOutputStream = ObjectOutputStream(byteArrayOutputStream)
objectOutputStream.writeObject(this)
objectOutputStream.flush()
val result = byteArrayOutputStream.toByteArray()
byteArrayOutputStream.close()
objectOutputStream.close()
return result
}
data class ListToPass(
var test: List<String>
) : Serializable
wear code to handle the data:
val payload = DataMapItem.fromDataItem(dataEvent.dataItem)
.dataMap.getAsset(WearViewModel.MISSION_KEY)

Base64Utils.encode does not produce valid base64 encoding

I am trying to encode a byte array in base64 before sending it over the network. The output of the encode() function below is not a valid base64 because what I read from my research was that the length of the string needs to a multiple of 4. Also, the string is not padded with "=" if the length is not a multiple of 4. I am assuming since no one has had this problem before, is there something wrong in the code below which is making the base64 to not be a multiple of 4?
private val messageAdapter = Moshi.Builder()
.add(KotlinJsonAdapterFactory())
.build()
.adapter(RealTimePayload::class.java)
fun encode(realTimePayload: RealTimePayload): String? {
val jsonPayload = messageAdapter.toJson(realTimePayload)
val compressedData = zip(jsonPayload)
return Base64Utils.encode(compressedData)
}
fun decode(encodedString: String): RealTimePayload? {
val gzippedData = Base64Utils.decode(encodedString)
val jsonData = unzip(gzippedData)
return messageAdapter.fromJson(jsonData)
}
private fun unzip(content: ByteArray): String =
GZIPInputStream(content.inputStream()).bufferedReader().use { it.readText() }
private fun zip(content: String): ByteArray {
val bos = ByteArrayOutputStream()
GZIPOutputStream(bos).bufferedWriter().use { it.write(content) }
return bos.toByteArray()
}
}
Edit: I should mention that the final encoded string has some trailing '='s but the length is still not a multiple of 4.
Let me know if I should provide more information? Thanks.

Are there some line terminators in the encoded string?
The com.google.android.gms.common.util.Base64Utils#encode passes flag 0 to the Base64#encodeToString. This means the result will be a multi-lined, padded, non url-safed string.

Kotlin: How to convert an image Uri to Bitmap to Base64

I've found lots of answers related tothis in Java, supposedely a Kotlin solution would be very much like Java, but as in many other things, the devil is on the details, and there are some.
I have several Uris stores in the SQLite database I'm using, now I want to send this images to an API that will catch them along with other data. I'll send the info via POST.
So now, I want to load the Uri, as I do when I use an ImageView.setImageURI() that will take the Uri, convert to Bitmap and place it in the ImageView container.
How do I convert from that Uri to a Bitmap object, and then encode it to Base64 to send it to the API, using Kotlin code?
EDIT
I'm trying with Anupam's imageFileToBase64() which seems to be exactly what I want, now I'm having a problem, I got a FileNotFoundException. This is what I'm doing.
I recover the Uri string from the database, it is a string that reads: content://media/external/images/media/109, so I convert it to an Uri
val uri = Uri.parse(uri_string)
Then I get the real path, and convert it to File
val file = File(uri.path)
Finally I call the function
val base64 = imageFileToBase64(file)
I have tried both with uri.path and uri.toString() and got the same results.
uri.path = /external/images/media/109
uri.toString() = content:/media/external/images/media/109
So I got no idea on what to pass to the function.

These are Kotlin methods for the following -
1. Get the bitmap from assets
2. Save bitmap to a file
3. Get Base64 from bitmap
4. Encode File/Image to Base64
5. Decode Base64 to File/Image
// Get the bitmap from assets and display into image view
val bitmap = assetsToBitmap("tulip.jpg")
// If bitmap is not null
bitmap?.let {
image_view_bitmap.setImageBitmap(bitmap)
}
val imagePath = "C:\\base64\\image.png"
// Encode File/Image to Base64
val base64ImageString = encoder(imagePath)
println("Base64ImageString = $base64ImageString")
// Decoder Base4 to File/Image
decoder(base64ImageString, "C:\\base64\\decoderImage.png")
// Click listener for button widget
button.setOnClickListener{
if(bitmap!=null){
// Save the bitmap to a file and display it into image view
val uri = bitmapToFile(bitmap)
image_view_file.setImageURI(uri)
// Show a toast message
toast("Bitmap saved in a file.")
}else{
toast("bitmap not found.")
}
}
}
// Method to get a bitmap from assets
private fun assetsToBitmap(fileName:String):Bitmap?{
return try{
val stream = assets.open(fileName)
BitmapFactory.decodeStream(stream)
}catch (e:IOException){
e.printStackTrace()
null
}
}
// Method to save an bitmap to a file
private fun bitmapToFile(bitmap:Bitmap): Uri {
// Get the context wrapper
val wrapper = ContextWrapper(applicationContext)
// Initialize a new file instance to save bitmap object
var file = wrapper.getDir("Images",Context.MODE_PRIVATE)
file = File(file,"${UUID.randomUUID()}.jpg")
try{
// Compress the bitmap and save in jpg format
val stream:OutputStream = FileOutputStream(file)
bitmap.compress(Bitmap.CompressFormat.JPEG,100,stream)
stream.flush()
stream.close()
}catch (e:IOException){
e.printStackTrace()
}
// Return the saved bitmap uri
return Uri.parse(file.absolutePath)
}
// Method to get Base64 from bitmap
private fun imageFileToBase64(imageFile: File): String {
return FileInputStream(imageFile).use { inputStream ->
ByteArrayOutputStream().use { outputStream ->
Base64OutputStream(outputStream, Base64.DEFAULT).use { base64FilterStream ->
inputStream.copyTo(base64FilterStream)
base64FilterStream.flush()
outputStream.toString()
}
}
}
}
// Encode File/Image to Base64
private fun encoder(filePath: String): String{
val bytes = File(filePath).readBytes()
val base64 = Base64.getEncoder().encodeToString(bytes)
return base64
}
// Decode Base64 to File/Image
private fun decoder(base64Str: String, pathFile: String): Unit{
val imageByteArray = Base64.getDecoder().decode(base64Str)
File(pathFile).writeBytes(imageByteArray)
}