ES6 from Java, using Nashorn

[Olivier]

Hi experts,
I want to run ES6 scripts from Java, using Nashorn.
I have scripts involving 'let', 'const', my Java code is happy with it, 
I just need to use a property "nashorn.args" set to "--language=es6".

Now, I'd like to move forward, use imports and modules.
I have one script like this (modules.01.js):

function displayMessage() {
 console.log("Hello JS World!");
};

export default displayMessage;

I want to consume it from this (modules.consume.js):

import displayMessagefrom './modules.01';

displayMessage();

But this is where I have a question:
My engine.eval("load('./modules.consume.js');"); complains about the "import" 
statement.
In the transpiled version, it complains about the "require" statement.

I must be missing something... I attach my code, in case it's needed.

Any idea, pointer, comment, help, etc, most welcome,
Thank you!
- Olivier



package scripting;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptEngineManager;
import java.io.File;
import java.io.FileReader;
import java.util.List;
import java.util.stream.Collectors;

public class Executor {
        private final static String SCRIPT_TO_RUN = "es6" + File.separator + 
"out" + File.separator + "modules.consume.js"; // Transpiled
//private final static String SCRIPT_TO_RUN = "es6" + File.separator + 
"modules.consume.js"; // Not transpiled

        private final static String NASHORN_ARGS = "nashorn.args";
        private final static String ES_6 = "--language=es6";


        public static void main(String... args) throws Exception {

                System.out.println(String.format("Running from [%s]", 
System.getProperty("user.dir")));

                String script =  SCRIPT_TO_RUN;
                if (args.length > 0) {
                        script = args[0];
                }

                System.setProperty(NASHORN_ARGS, ES_6);

                ScriptEngineManager factory = new ScriptEngineManager();
                List<ScriptEngineFactory> engineFactories = 
factory.getEngineFactories();
                System.out.println(String.format("%s factory(ies).", 
engineFactories.size()));
                engineFactories.stream().forEach(ef -> {
                        System.out.println(String.format("%s (%s)",
                                        ef.getEngineName(),
                                        
ef.getNames().stream().collect(Collectors.joining(", "))));
                });

                ScriptEngine engine = factory.getEngineByName("nashorn");
                FileReader reader = new FileReader(script);
                try {
                        engine.eval(reader);
                } catch (Exception ex) {
                        System.err.println("Ooops:" + ex.toString());
                } finally {
                        reader.close();
                }
                // Another approach
                try {
                        String command = String.format("load('%s');", script);
                        System.out.println(String.format("Executing [%s]", 
command));
                        engine.eval(command);
                } catch (Exception ex) {
                        ex.printStackTrace();
                }

                engine.eval("print('Bye now.');");
        }
}