Rename a file in Kotlin

This post will discuss how to rename a file in Kotlin.

1. Using `File#renameTo()` function

A simple solution is to use the File#renameTo() function for renaming a file, which returns a boolean value indicating whether the renaming was successful or not. Note that the function’s behavior is platform-dependent, and it doesn’t throw a java.io.IOException on I/O failure.

The following solution demonstrates the usage of the File#renameTo() function. Note that if the file is renamed successfully, a success message is displayed. If the source file doesn’t exist, java.nio.file.NoSuchFileException is thrown. If the destination path already exist, java.nio.file.FileAlreadyExistsException is thrown.

import java.io.File

import java.io.IOException

import java.nio.file.FileAlreadyExistsException

import java.nio.file.NoSuchFileException

fun main() {

try {

val src = File("source.txt")

if (!src.exists()) {

throw NoSuchFileException("Source file doesn't exist")

}

val dest = File("destination.txt")

if (dest.exists()) {

throw FileAlreadyExistsException("Destination file already exist")

}

val success = src.renameTo(dest)

if (success) {

println("Renaming succeeded")

}

} catch (e: IOException) {

e.printStackTrace()

}

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2. Using `Files.move()` function

Alternately, we can use the Files.move() function to rename (or move) a file that throws a java.io.IOException if an I/O error occurs. The usage is demonstrated below:

import java.io.IOException

import java.nio.file.Files

import java.nio.file.Paths

fun main() {

val src = Paths.get("source.txt")

val dest = Paths.get("destination.txt")

try {

Files.move(src, dest)

println("Renaming succeeded")

} catch (e: IOException) {

e.printStackTrace()

}

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If the target file already exists, the Files.move() function throws java.nio.file.FileAlreadyExistsException. To replace the target file, we can specify the REPLACE_EXISTING option.

import java.io.IOException

import java.nio.file.Files

import java.nio.file.Paths

import java.nio.file.StandardCopyOption

fun main() {

val src = Paths.get("source.txt")

val dest = Paths.get("destination.txt")

try {

Files.move(src, dest, StandardCopyOption.REPLACE_EXISTING)

println("Renaming succeeded")

} catch (e: IOException) {

e.printStackTrace()

}

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That’s all about renaming a file in Kotlin.

1. Using File#renameTo() function

2. Using Files.move() function

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1. Using `File#renameTo()` function

2. Using `Files.move()` function