Use Intent.ACTION_GET_CONTENT to import or read file.
val intent = Intent(Intent.ACTION_GET_CONTENT)// intent.type = "file/*"intent.type = "application/octet-stream"activity.startActivityForResult(intent, FILE_REQUEST_CODE)Edit AndroidManifest.xml to allow reading of open/import file.
<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
</manifest>Override Activity.onActivityResult to handle the file request.
Use ContentResolver.openInputStream to read input stream / the file.
class BackupActivity : AppCompatActivity() { companion object { private const val FILE_REQUEST_CODE = 1 } override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) { super.onActivityResult(requestCode, resultCode, data) if (requestCode == FILE_REQUEST_CODE) { if (resultCode == Activity.RESULT_OK) { val uri = data?.data if (uri != null) { val inputStream = contentResolver.openInputStream(uri) // copy input stream to file val outputFile = File(context.cacheDir, "output.txt") val outputStream = FileOutputStream(outputFile) inputStream.use { input -> outputStream.use { output -> input.copyTo(output) } } // copy input stream to bytearray/string /* val outputStream = ByteArrayOutputStream() inputStream.use { input -> outputStream.use { output -> input.copyTo(output) } } val byteArray = outputStream.toByteArray() val outputString = String(byteArray, Charsets.UTF_8) */ } else { Toast.makeText(this, "No Data", Toast.LENGTH_LONG).show() } } else { Toast.makeText(this, "No Result", Toast.LENGTH_LONG).show() } } }}