I want to call Kotlin functions from Java, but whe...

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[Joakim Tengstrand]

I want to call Kotlin functions from Java, but when I disassamble the compiled Kotlin code, I can see that the types are e.g. kotlin.String instead of java.lang.String. Is there a way to compile the Kotlin code to Java types directly, or do we need to call the Kotlin code with e.g. kotlin.String, and if so, how do we convert from Java types to Kotlin types?

[diesieben07]

kotlin.String is a fictional type, it becomes java.lang.String when compiling for the JVM.
https://kotlinlang.org/docs/reference/java-interop.html#mapped-types

[Joakim Tengstrand]

package jocke.polylith.kotlin

public fun hello(value: kotlin.String): kotlin.Unit { /* compiled code */ }

public fun helloval(value: <http://kotlin.Int|kotlin.Int>): kotlin.Unit { /* compiled code */ }

public fun main(args: kotlin.Array<kotlin.String>): kotlin.Unit { /* compiled code */ }

When I decompiled the class file, it doesn't seem so.

[diesieben07]

You decompiled it to kotlin (not sure how you did that?), which means it'll do the translation again.

[Joakim Tengstrand]

I just dropped the class file in IntelliJ IDEA, and then it showed up like this.

[diesieben07]

In a kotlin class you can just do Tools > Kotlin > Show Kotlin Bytecode

[diesieben07]

or even Tools > Kotlin > Decompile Kotlin to Java

[Joakim Tengstrand]

We are building a library that will be consumed from Java (or actually Clojure, but they are compatible). I now tried to call a function with no arguments and now I got the error: Syntax error (NoSuchFieldException)
...even though the intellisense works from IntelliJ IDEA.

[Joakim Tengstrand]

It works now. Thanks for the help!