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Kotlin – How to read File with Kotlin language

loizenai
Software Engineer - Founder at https://loizenai.com
・2 min read

https://grokonez.com/kotlin/kotlin-read-file-kotlin-language

Kotlin – How to read File with Kotlin language

This tutorial shows you how to read File in Kotlin using InputStream or BufferedReader.

I. Technology

  • Java 1.8
  • Kotlin 1.1.2

    II. Overview

    1. Goal

    Read file: all lines/by line using InputStream or BufferedReader or File directly.

    2. Steps to do

  • Create:
  • InputStream from File, then get BufferedReader using bufferedReader() method
  • BufferedReader from File.
  • Use:
  • Closeable.use() method with Reader.readText() method inside block. Closeable.use() will automatically close the input at the end of the lambda's execution:
    
    String = (Reader implements Closeable).use(Reader.readText())
    
  • Reader.useLines() method with Kotlin Sequence (a sequence of all the lines) inside block. Reader.useLines() will automatically close the reader once the processing is complete:
    
    Reader.useLines(block: Sequence)
    
  • File.useLines() method with Kotlin Sequence (a sequence of all the lines) inside block. It will close the reader once the processing is complete:
    
    File.useLines(block: Sequence)
    
  • File.readLines() method to return a List<String>:
    
    File.readLines()
    

    III. Practice

    0. kotlin.txt

More at:

https://grokonez.com/kotlin/kotlin-read-file-kotlin-language

Kotlin – How to read File with Kotlin language

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