Kotlin Scripts
Problem
Java and Kotlin are nice languages for software development, but for small scripts, you have so far probably used languages like Python or JavaScript. There is nothing wrong with these languages per se, but the syntax and standard libraries are different from JVM languages and I tend to use google a lot to write the scripts.
Solution
For writing scripts in Kotlin, you don't need Gradle build scripts, package.json or similar. You can directly specify the dependencies in the script file and then just write Kotlin code. The file must end in .main.kts and Intellij IDEA supports it natively. Below is a small script that queries the well-known Petstore API. To run it, you need to install Java and the Kotlin compiler. On Windows, you can download it from Github (kotlin-compiler-X.X.XX.zip) and then add the bin folder to the PATH. On Linux, you can use e.g. snap `sudo snap install --classic kotlin`, on Mac e.g. homebrew `brew install kotlin`.
Example
@file:DependsOn("io.ktor:ktor-client-okhttp:+")
@file:DependsOn("io.ktor:ktor-client-gson:+")
import io.ktor.client.*
import io.ktor.client.features.json.*
import io.ktor.client.request.*
import kotlinx.coroutines.runBlocking
data class InventoryResponse(val sold: Int, val pending: Int, val available: Int)
val url = "https://petstore.swagger.io/v2/store/inventory"
HttpClient { install(JsonFeature) }.use { client ->
runBlocking {
val (sold, pending, available) = client.get<InventoryResponse>(url)
println("Result: Sold $sold, pending $pending, available $available")
}
}C:\Users\findu\Development>kotlin petstore.main.kts
# Warnings about reflective access if Java version > 1.8
Result: Sold 4, pending 4, available 666
Further Aspects
- Kotlin scripts are already quite stable, but there are still a few bugs. KT-28475, KT-43520 etc., but they are constantly being fixed.
- Code: https://jamb.it/kotlinscript
- I can recommend every Java developer to have a look at Kotlin, it is a nice language.
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Author: Sebastian Lehrbaum / Software Architect / Business Division Automotive
Download Toilet Paper #142: Kotlin Scripts (PDF)
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