Hi guys, Just wondering if I can find an overview...

# getting-started

[huehnerlady]

Hi guys,

Just wondering if I can find an overview somewhere which kotlin version supports which java?
Here I can see under jvmTarget that version 1.3.72 seems to support Java13, but when I try it out I get the error “Unsupported class file major version 57”, which made me wonder if it was supported after all? 🤔

[deactivateduser]

hi, during what activity did you get this error message? and how did you do that?

[crummy]

You might need to explicitly specify the jvm version you're targeting, e.g:

compileJava {
    sourceCompatibility = '13'
    targetCompatibility = '13'
}

[huehnerlady]

I have a gradle project set up with kotlin dsl and the kotlin plugins with version 1.3.72

org.jetbrains.kotlin.jvm
org.jetbrains.kotlin.plugin.spring
org.jetbrains.kotlin.plugin.allopen

and with kotlin options

kotlinOptions {
        jvmTarget = javaVersion.toString()
        freeCompilerArgs = listOf("-Xjsr305=strict")
      }

Also has a section

configure<JavaPluginConvention> {
    sourceCompatibility = javaVersion
    targetCompatibility = javaVersion
  }

Whereby javaVersion is VERSION_12 of the gradle API.

That works fine.
When I bump up the javaVersion to VERSION_13 I get the mentioned error

I didn’t say it came from the kotlin, just made me wonder if there is an official place where I can see which version supports which jvmTargets 🙂

[araqnid]

I use Kotlin 1.3.72 with Java14, so it’s not as simple a compatibility problem as that. Looks like something is running an older JVM at some point in the process.

[huehnerlady]

cool thanks, as I said I am not saying it was kotlin, but it makes me wonder to get to know which kotlin version supports which jvmTarget. Is there any changelog that could be useful for example?