How to reuse class for multiple ConfigurationProperties in Kotlin

[LegoRocks]

In my Kotlin application, I have a set of feature flags. However these flags are not globally set but may different for certain business and functions and should be configured using the application.yml. My yml looks something like this:

app:
  flags:
    function1:
      flag1: true
      flag2: false
      flag3: true
    function2:
      flag1: false
      flag2: true
      flag3: false
    function3:
      flag1: false
      flag2: false
      flag3: false

I want to bind them using @ConfigurationProperties and built the following:

@ConfigurationProperties("app.flags")
class FeatureFlagSettings {
   var function1: FeatureFlagProperties
   var function2: FeatureFlagProperties
   var function3: FeatureFlagProperties
}

class FeatureFlagProperties {
   var flag1: Boolean
   var flag2: Boolean
   var flag3: Boolean
}

But I quickly realized, that the properties are not properly set. Apparently this is way of building properties only works for Java but not Kotlin. Of course I could simply copy and paste the FeatureFlagProperties class for each function with it's own class name and @ConfigurationProperties but that seems not like the proper way of doing things.

Is there a way to use @ConfigurationProperties and reuse a class with reocurring properties? I know there is the @EachProperty annotation but my use case is for predefined properties, not a generic collection of entries.

[TatyOko28]

Solution : Use data class with default values (Recommended)

import io.micronaut.context.annotation.ConfigurationProperties

@ConfigurationProperties("app.flags")
class FeatureFlagSettings {
    var function1: FeatureFlagProperties = FeatureFlagProperties()
    var function2: FeatureFlagProperties = FeatureFlagProperties()
    var function3: FeatureFlagProperties = FeatureFlagProperties()
}

class FeatureFlagProperties {
    var flag1: Boolean = false
    var flag2: Boolean = false
    var flag3: Boolean = false
}