Check this post - https://www.baeldung.com/kotlin/csv-files - it contains a few nice references to some libraries or pure Kotlin approaches if you prefer to use those.

Applying it to your use case, maybe something like:

fun OutputStream.writeCsv(context: Context, listOfData: List<YourData>) {
    //get data create directory
   ......

    val writer = bufferedWriter()
    writer.write(""""Name", "Address", "Code"""")
    writer.newLine()
    listOfData.forEach {
        writer.write("${it.name}, ${it.address}, \"${it.code}\"")
        writer.newLine()
    }
    writer.flush()
    writer.close()
}

And then call this where you need it,

FileOutputStream("out777.cs").apply { writeCsv(listOfData) }

One thing to note here is using bufferedWriter:

FileWriter writes directly into Files and should be used only when the number of writes is less. BufferedWriter: BufferedWriter is almost similar to FileWriter but it uses internal buffer to write data into File. So if the number of write operations is more, the actual IO operations are less and performance is better.

Not tested but this might point you in a more cleaner and efficient solution. There are also some libraries specifically for this. Take a look

That tutorial on using Apache Commons for reading CSV is written with the assumption that you are writing for JVM, not Android. It's not simple to adapt it to Android. I don't think the Apache Commons library is necessary anyway, because CSV is such a simple text-based format.

Here are a couple of simple extension functions that can be called on a File to either read a CSV as a 2D List of Strings, or write a 2D List of Strings to a File. Think of the 2D list as a List of lines of data. Each value in the inner List is all the values in that line.

@Throws(IOException::class)
fun File.readAsCSV(): List<List<String>> {
    val splitLines = mutableListOf<List<String>>()
    forEachLine {
        splitLines += it.split(", ")
    }
    return splitLines
}

@Throws(IOException::class)
fun File.writeAsCSV(values: List<List<String>>) {
    val csv = values.joinToString("\n") { line -> line.joinToString(", ") }
    writeText(csv)
}

You should not do File IO operations on the main thread, because this freezes the UI and risks making your application crash with the Application Not Responding Error. It looks like you have some kind of game loop so I'm not sure how to apply this advice in your case.

Here are alternate versions of the above functions that use FileInputStream and FileOutputStream so they are more versatile on Android (since you can't get direct File access for some storage locations):

@Throws(IOException::class)
fun FileInputStream.readAsCSV() : List<List<String>> {
    val splitLines = mutableListOf<List<String>>()
    reader().buffered().forEachLine {
        splitLines += it.split(", ")
    }
    return splitLines
}

@Throws(IOException::class)
fun FileOutputStream.writeAsCSV(values: List<List<String>>) {
    val csv = values.joinToString("\n") { line -> line.joinToString(", ") }
    writer().buffered().use { it.write(csv) }
}

After writing to the file you must close it:
fileWriter.close()
and make this change:
sendIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(qponFile))