Read a file in Kotlin

This article covers different ways to read the contents of a file in Kotlin.

1. Using `BufferedReader.lines()` function

In Kotlin, you can use the BufferedReader.lines() function to get a Stream of lines of text read from BufferedReader.

import java.io.BufferedReader

import java.io.File

import java.io.FileReader

fun main() {

val file = File("/app/logs/january.log")

val reader = BufferedReader(FileReader(file, Charsets.UTF_8))

reader.lines().forEach { println(it) }

}

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2. Using `Files.lines()` function

Alternatively, you can use the Files.lines() function to read all lines from a file using the specified charset.

import java.nio.file.Files

import java.nio.file.Paths

fun main() {

val path = Paths.get("/app/logs/january.log")

Files.lines(path, Charsets.UTF_8).forEach { println(it) }

}

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3. Using `Files.readAllLines()` function

Another plausible way to read all lines from a file using the specified charset is to use the Files.readAllLines() function.

import java.nio.file.Files

import java.nio.file.Paths

fun main() {

val path = Paths.get("/app/logs/january.log")

Files.readAllLines(path, Charsets.UTF_8).forEach { println(it) }

}

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4. Using `Files.readAllBytes()` function

Another alternative is to use the readAllBytes() function, which returns a byte array having the bytes read from the specified file. To get a string out of file contents, you can pass the byte array to the String constructor.

import java.nio.file.Files

import java.nio.file.Paths

fun main() {

val path = Paths.get("/app/logs/january.log")

val encoded = Files.readAllBytes(path)

var content = String(encoded, Charsets.UTF_8)

println(content)

}

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5. Using `Files.readString()` function

Finally, you can also use the Files.readString() function to read all characters from a file into a string using the specified charset.

import java.nio.file.Files

import java.nio.file.Paths

fun main() {

val filePath = "/app/logs/january.log"

var content = Files.readString(Paths.get(filePath), Charsets.UTF_8)

println(content)

}

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That’s all about reading a file in Kotlin.

1. Using BufferedReader.lines() function

2. Using Files.lines() function

3. Using Files.readAllLines() function

4. Using Files.readAllBytes() function

5. Using Files.readString() function

Share this:

1. Using `BufferedReader.lines()` function

2. Using `Files.lines()` function

3. Using `Files.readAllLines()` function

4. Using `Files.readAllBytes()` function

5. Using `Files.readString()` function