Declaring actual val in Java

Multiplatform
1

I am working on the KMP library, which should be called from multiple platforms.

Starting with multiplatform-library-template, I try to add Java code to call CommonMain Kotlin function.

The CommonMain Kotlin code also declares:

expect val firstElement: Int
expect val secondElement: Int

How to declare actual values in Java code (in JvmMain module)?

2

Write exactly the same line, replacing expect by actual, in src/jvmMain/kotlin. The package declaration at the top of the file should be exactly the same, but the file doesn’t have to be named the same.

3

In Kotlin – I understand. How I can do this in Java?
I need the Java developer, using this library from Java application, to be able to provide actual for these val’s

4

You cannot write it directly in Java. However, you can implement them by calling a Java method.

class JavaGenerator {
    static int generateFirstElement() {
        …
    }
}

actual val firstElement: Int = JavaGenerator.generateFirstElement()
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