envkeg

A very small boilerplate-free kotlin library to read values from environment variables in a typesafe way.

Usage

Single values

To read an environment variable simply call:

parseFromEnv("myEnvInt", 30)

to get myEnvInt from the environment as an Int or

val nullableInt: Int? = parseFromEnv("myNullableEnvInt")

to get myNullableEnvInt from the environment as an Int?.

If the variable is not present, can't be parsed or the target type is not supported, 30 is returned in the first case, whereas null is returned in the second case.

Lists

You can also convert an environment variable to a List. Let's say the variable is named myIntList and the content is "1,2,3".

val intList: List<Int> = parseListFromEnv("myIntList")

returns a List<Int> of [1,2,3].

You can also define your own separator by calling for example parseListFromEnv("myOtherIntList", ';').

Install dependency

This dependency is available at Maven Central.

Note: Prior to version 0.5.0.1, envkeg is only available at jcenter. After 0.5.0, envkeg moved to maven central.

Gradle

dependencies {
    ...
    implementation("de.breuco:envkeg:0.5.1")
    ...
}

Maven

<?xml version="1.0" encoding="UTF-8"?>
<project>
    ...
    <dependencies>
        <dependency>
            <groupId>de.breuco</groupId>
            <artifactId>envkeg</artifactId>
            <version>0.5.1</version>
        </dependency>
    </dependencies>
    ...
</project>

Supported types

Type	Parsing function
Byte	String.toByte()
Short	String.toShort()
Int	String.toInt()
Long	String.toLong()
Float	String.toFloat()
Double	String.toDouble()
Boolean	String.toBoolean()
LocalDate	LocalDate.parse(...)
LocalDateTime	LocalDateTime.parse(...)
OffsetTime	OffsetTime.parse(...)
OffsetDateTime	OffsetDateTime.parse(...)
ZonedDateTime	ZonedDateTime.parse(...)
Instant	Instant.parse(...)
String	none