I'm trying to find a solution to simply download a base64 encoded pdf file of a webservice and open it with an preinstalled pdf viewer. My application targets Android R. I tried something like this but I dont't want a picker to open.
This is my code so far. It is just downloading the file and converts it to a bytearray. The next step should by saving the file and opening it.
lifecycleScope.launch {
withContext(Dispatchers.IO) {
try {
Snackbar.make(binding.root, getString(R.string.load_document_started), Snackbar.LENGTH_LONG).show()
val documentData = DocumentDao().get(document.id, montageOrder)
val docAsByte = Base64.decode(documentData.data, Base64.DEFAULT)
val currentDateString = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
val fileName = document.documentType.
lowercase()
.replace("ä", "ae")
.replace("ü", "ue")
.replace("ö", "oe") +
"_" + currentDateString
val file = File(requireContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), fileName)
val fileStream = FileOutputStream(file)
fileStream.write(docAsByte)
fileStream.close()
val target = Intent(Intent.ACTION_VIEW)
target.setDataAndType(Uri.fromFile(file), "application/pdf")
target.flags = Intent.FLAG_ACTIVITY_NO_HISTORY
val intent = Intent.createChooser(target, "Yolo");
startActivity(intent)
} catch (e: Exception) {
Log.e(TAG, "Dokument konnte nicht geladen werden: " + e.message, e)
Snackbar.make(binding.root, getString(R.string.exception_could_not_load_document), Snackbar.LENGTH_LONG).show()
}
}
}
This results in a FileUriExposedException
Another aproach was using the SAF
lateinit var docAsByte : ByteArray
private val createFileLauncher = registerForActivityResult(CreatePdfDocument()) { uri ->
lifecycleScope.launch {
withContext(Dispatchers.IO) {
val stream = requireContext().contentResolver.openOutputStream(uri)
stream?.write(docAsByte)
stream?.close()
val target = Intent(Intent.ACTION_VIEW)
target.setDataAndType(uri, "application/pdf")
target.flags = Intent.FLAG_ACTIVITY_NO_HISTORY
startActivity(target)
}
}
}
private fun setGui() {
_binding?.lvDocuments?.adapter = DocumentAdapter(requireContext(), montageOrder.documents)
_binding?.lvDocuments?.setOnItemClickListener { parent, _, position, _ ->
val document : Document = parent.getItemAtPosition(position) as Document
lifecycleScope.launch {
withContext(Dispatchers.IO) {
try {
val currentDateString = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
val fileName = document.documentType.
lowercase()
.replace("ä", "ae")
.replace("ü", "ue")
.replace("ö", "oe") +
"_" +
montageOrder.orderNumber +
"_" +
currentDateString +
".pdf"
Snackbar.make(binding.root, getString(R.string.load_document_started), Snackbar.LENGTH_LONG).show()
val documentData = DocumentDao().get(document.id, montageOrder)
docAsByte = Base64.decode(documentData.data, Base64.DEFAULT)
createFileLauncher.launch(fileName)
} catch (e: Exception) {
Log.e(TAG, "Dokument konnte nicht geladen werden: " + e.message, e)
Snackbar.make(binding.root, getString(R.string.exception_could_not_load_document), Snackbar.LENGTH_LONG).show()
}
}
}
}
}
Everything works fine except for opening. But if I open the pdf via file explorer it works.
Solved it this way
Add provider_paths.xml to xml resource folder
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="external_files" path="."/>
</paths>
In your manifest add a FileProvider:
<application>
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths" />
</provider>
</application>
Prepare to download files to any directory your app owns, such as getFilesDir(), getExternalFilesDir(), getCacheDir() or getExternalCacheDir().
val privateDir = context.getFilesDir()
Download file taking its progress into account (DIY):
val downloadedFile = myFancyMethodToDownloadToAnyDir(url, privateDir, fileName)
Copy it to Downloads folder:
private val DOWNLOAD_DIR = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
val finalUri : Uri? = copyFileToDownloads(context, downloadedFile)
fun copyFileToDownloads(context: Context, downloadedFile: File): Uri? {
val resolver = context.contentResolver
return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, getName(downloadedFile))
put(MediaStore.MediaColumns.MIME_TYPE, getMimeType(downloadedFile))
put(MediaStore.MediaColumns.SIZE, getFileSize(downloadedFile))
}
resolver.insert(MediaStore.Downloads.EXTERNAL_CONTENT_URI, contentValues)
} else {
val authority = "${context.packageName}.provider"
val destinyFile = File(DOWNLOAD_DIR, getName(downloadedFile))
FileProvider.getUriForFile(context, authority, destinyFile)
}?.also { downloadedUri ->
resolver.openOutputStream(downloadedUri).use { outputStream ->
val brr = ByteArray(1024)
var len: Int
val bufferedInputStream = BufferedInputStream(FileInputStream(downloadedFile.absoluteFile))
while ((bufferedInputStream.read(brr, 0, brr.size).also { len = it }) != -1) {
outputStream?.write(brr, 0, len)
}
outputStream?.flush()
bufferedInputStream.close()
}
}
Once in download folder you can open file from app like this:
val authority = "${context.packageName}.provider"
val intent = Intent(Intent.ACTION_VIEW).apply {
setDataAndType(finalUri, getMimeTypeForUri(finalUri))
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.LOLLIPOP) {
addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION or Intent.FLAG_GRANT_READ_URI_PERMISSION)
} else {
addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
}
}
try {
context.startActivity(Intent.createChooser(intent, chooseAppToOpenWith))
} catch (e: Exception) {
Toast.makeText(context, "Error opening file", Toast.LENGTH_LONG).show()
}
//Kitkat or above
fun getMimeTypeForUri(context: Context, finalUri: Uri) : String =
DocumentFile.fromSingleUri(context, finalUri)?.type ?: "application/octet-stream"
//Just in case this is for Android 4.3 or below
fun getMimeTypeForFile(finalFile: File) : String =
DocumentFile.fromFile(it)?.type ?: "application/octet-stream"