Check whether a file is empty in Kotlin

This post will discuss how to check whether a file is empty in Kotlin.

1. Using `BufferedReader.readLine()` function

The readLine() function of the BufferedReader class returns null if the end of the stream is reached without reading any characters. We can use this to check whether a file is empty, as shown below:

import java.io.BufferedReader

import java.io.File

import java.io.FileReader

import java.io.IOException

fun main() {

val file = File("/data/app.log")

try {

val br = BufferedReader(FileReader(file))

if (br.readLine() == null) {

println("File is empty")

}

} catch (e: IOException) {

e.printStackTrace()

}

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2. Using `File.length()` function

Another alternative is to construct the File object and call its length() function to get the file’s length. The file is empty if and only if its length is 0.

import java.io.File

fun main() {

val file = File("/data/app.log")

if (file.length() == 0L) {

println("File is empty")

}

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This approach is not recommended since the length() function returns 0 even when the file does not exist, is a directory, or an I/O error occurs.

That’s all about checking whether a file is empty in Kotlin.

Check whether a file is empty in Kotlin

1. Using BufferedReader.readLine() function

2. Using File.length() function

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1. Using `BufferedReader.readLine()` function

2. Using `File.length()` function