Can I run kotlin as script with Java Scripting API

Question

I want to run kotlin code as script from java with Java Scripting API similar to this for javascript:

import javax.script.*;
public class EvalScript {
    public static void main(String[] args) throws Exception {
        // create a script engine manager
        ScriptEngineManager factory = new ScriptEngineManager();
        // create a JavaScript engine
        ScriptEngine engine = factory.getEngineByName("JavaScript");
        // evaluate JavaScript code from String
        engine.eval("print('Hello, World')");
    }
}

or with similar APIs like this.

Answer 1

Yes, it's possible starting from the Kotlin 1.1: http://kotlinlang.org/docs/reference/whatsnew11.html#javaxscript-support

KEEP-75 has an example of the JSR-223 API call:

val engine = ScriptEngineManager().getEngineByExtension("main.kts")!!
engine.eval("""
@file:DependsOn("junit:junit:4.11")

org.junit.Assert.assertTrue(true)

println("Hello, World!")
""")

Configuration below adds Kotlin scripts engine to my Kotlin 1.2 project:

• META-INF/services/javax.script.ScriptEngineFactory file with the content from the https://github.com/JetBrains/kotlin/blob/master/libraries/examples/kotlin-jsr223-local-example/src/main/resources/META-INF/services/javax.script.ScriptEngineFactory

• 2 libraries:

        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-script-runtime</artifactId>
            <version>${kotlin.version}</version>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-script-util</artifactId>
            <version>${kotlin.version}</version>
        </dependency>

Update: Starting from Kotlin 1.2.20 kotlin-script-util doesn't depend on kotlin-compiler explicitly (see https://youtrack.jetbrains.com/issue/KT-17561). So one more module should be provided (as of the build file in example project):

        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-compiler-embeddable</artifactId>
            <version>${kotlin.version}</version>
        </dependency>

Answer 2

Kotlin support for the Java Scripting API is planned, but as of version 1.0.3 is not available yet. For the mean time, you can try to use an existing open-source implementation.