In Kotlin, how do I read the entire contents of an InputStream into a String?

Question

I recently saw code for reading entire contents of an InputStream into a String in Kotlin, such as:

// input is of type InputStream
val baos =         


        

Answer 1

【Method 1 | Manually Close Stream】

private fun getFileText(uri: Uri):String {
    val inputStream = contentResolver.openInputStream(uri)!!

    val bytes = inputStream.readBytes()        //see below

    val text = String(bytes, StandardCharsets.UTF_8)    //specify charset

    inputStream.close()

    return text
}

• inputStream.readBytes() requires manually close the stream: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/java.io.-input-stream/read-bytes.html

---

【Method 2 | Automatically Close Stream】

private fun getFileText(uri: Uri): String {
    return contentResolver.openInputStream(uri)!!.bufferedReader().use {it.readText() }
}

• You can specify the charset inside bufferedReader(), default is UTF-8: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/java.io.-input-stream/buffered-reader.html

• bufferedReader() is an upgrade version of reader(), it is more versatile: How exactly does bufferedReader() work in Kotlin?

• use() can automatically close the stream when the block is done: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/use.html