Unlock the Power of File Reading in Kotlin
When working with files in Kotlin, it’s essential to know how to read their contents efficiently. In this article, we’ll explore two ways to create a string from a file, covering the crucial aspects of file encoding and exception handling.
Setting the Stage
Let’s assume we have a file named test.txt in our src folder. This file contains the content we want to read and convert into a string.
Method 1: Reading All Lines
Our first approach involves reading all lines from the file using the readAllLines() method. This method takes the file path and encoding as parameters, returning a list of strings representing the file’s contents. Here’s the Kotlin code:
val path = System.getProperty("user.dir") + "/src/test.txt"
val lines = File(path).readLines(Charsets.defaultCharset())
println(lines)
When you run this program, the output will be a list of strings, each representing a line in the file. Note that readAllLines() may throw an IOException, so we need to define our main method accordingly.
Method 2: Reading All Bytes
Alternatively, we can read all bytes from the file using the readAllBytes() method. This approach returns a single string containing the file’s contents. Here’s the modified Kotlin code:
val path = System.getProperty("user.dir") + "/src/test.txt"
val bytes = File(path).readBytes()
val lines = String(bytes, Charsets.defaultCharset())
println(lines)
When you run this program, the output will be a single string containing all the contents of the file.
Java Equivalent
For those familiar with Java, here’s the equivalent code to create a string from a file:
// Java program to create a string from contents of a file
By mastering these two methods, you’ll be able to efficiently read file contents in Kotlin, taking into account file encoding and exception handling.