@Value with List in Kotlin from YAML

Question

I am trying to initialise a list of properties from a YAML file in a Spring Boot project with Kotlin.

It works fine for a normal string, but fails when I try to init a List with the following error:

Unexpected exception during bean creation; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'foo.bars' in value "${foo.bars}"

The Kotlin code has the following constructor argument

@Value("\${foo.bars}")
val foobars: List<String>

the yaml file has the following values:

foo:
  bars:
  - test1
  - test2

Do I need to do something different between Lists and normal Strings?

Answer 1

Solution described here can be changed a bit for Kotlin:

@Component
@ConfigurationProperties("foo")
class FooBarsProperties {
  lateinit var bars: List<String>
}

Simply inject FooBarsProperties where you need it. Don't forget to add @EnableConfigurationProperties to some of your configuration classes.