Kotlin and Java interoperability

This recipe is going to show how to combine both Java and Kotlin classes together and use them in the same application component. We will declare a Kotlin data class, called ColoredText, that holds two properties of the String and Color types. Apart from the properties, it is also going to expose a utility function inside a companion object responsible for text-processing. We are going to learn how to make use of those properties and how to declare the function from the ColoredText class to be visible as a JVM static method inside the Java class.

 

How to do it...

1. Declare the ColoredText class:

data class ColoredText
@JvmOverloads
constructor(
var text: String = "",
var color: Color = defaultColor) {

companion object {
@JvmField
val defaultColor = Color.BLUE
}
}

2. Implement a static JVM method inside the companion object:

data class ColoredText
@JvmOverloads
constructor(
var text: String = "",
var color: Color = defaultColor) {

companion object {
@JvmField
val...