Hi. I was trying to see if I could get some infor...

# getting-started

[wrongwrong]

Hi.

I was trying to see if I could get some information from a KFunction without kotlin-reflect (using kotlinx-metadata-jvm), but I couldn't get Metadata with valid information, so I have a question.

What I want to achieve is as follows.

1. get the information of arguments and return values from KFunction.
2. get javaConstructor or javaMethod from KFunction.

[wrongwrong]

A simple verification with the following code shows that although the Metadata annotation can be retrieved from a KFunction, the contents are almost empty.

package org.example

import kotlin.reflect.KFunction

data class DataClass(val value: String)

fun main() {
    val function: KFunction<*> = ::DataClass
    val metadata: Metadata = function::class.java.getAnnotation(Metadata::class.java)!!

    println(metadata.data1.asList()) // -> []
    println(metadata.data2.asList()) // -> []
}

On the other hand, looking at the bytecode of the synthetic class generated as a FunctionReference, it looks like there is a valid Metadata.
How can I get this Metadata?

Untitled

[wrongwrong]

If there is another way to get information from KFunction without using kotlin-reflect, I would be grateful if you could let me know.
Thank you.

[wrongwrong]

It solved itself in another way.
KFunction retrieved as Reference can be cast to kotlin.jvm.internal.FunctionReference, so various information could be read from it.
From (functionReference.owner as ClassBasedDeclarationContainer).jClass, we could also read information about the Class from which it was defined.