CODEWITHSUNDEEP
environment-variableskotlin
Bjornicus
Bjornicus

Reputation: 1165

How to read an environment variable in Kotlin?

I'd like to get a certain value from an environment variable in my Kotlin app, but I can't find anything about reading environment variables in the core libraries documentation.

I'd expect it to be under kotlin.system but there's really not that much there.

Upvotes: 75

Views: 70941

Answers (4)

suside
suside

Reputation: 694

And if you want to handle env var which do exists but is empty:

val myEnv = (System.getenv("MY_ENV") ?: "").ifEmpty { "default_value" }

(see edit history for previous versions)

Upvotes: 8

Patrick Boos
Patrick Boos

Reputation: 7029

It is really easy to get a environment value if it exists or a default value by using the elvis operator in kotlin:

val envVar: String = System.getenv("varname") ?: "default_value"

Upvotes: 118

LF-DevJourney
LF-DevJourney

Reputation: 28534

You can use the kotlin extension Konfig

Konfig - A Type Safe Configuration API for Kotlin

Konfig provides an extensible, type-safe API for configuration properties gathered from multiple sources — built in resources, system properties, property files, environment variables, command-line arguments, etc.

For example: Key("http.port", intType)

Upvotes: 3

Marcin Porwit
Marcin Porwit

Reputation: 281

You could always go down this approach:

val envVar : String? = System.getenv("varname")

Though, to be fair, this doesn't feel particularly idiomatic, as you're leveraging Java's System class, not Kotlin's.

Upvotes: 28

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