Java SimpleBindings bind Java variable to use in Javascript

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import javax.script.SimpleBindings;

public class Main {

   public static void main(String[] args) {
      String myJavaString = "This is a Java parameter!";

      ScriptEngineManager sem = new ScriptEngineManager();
      ScriptEngine nashorn = sem.getEngineByName("nashorn");
      try {/*w ww .j av  a  2s . c  o  m*/
         SimpleBindings simpleBindings = new SimpleBindings();
         simpleBindings.put("myString", myJavaString);
         nashorn.eval("print (myString)", simpleBindings);

         SimpleBindings simpleBindings2 = new SimpleBindings();
         simpleBindings2.put("v1", 2);
         simpleBindings2.put("v2", 3);
         nashorn.eval(
               "function add(a, b){var v = a +b; "//
                     + "return v; }"// 
                     + "print(add(v1, v2));",
               simpleBindings2);

      } catch (ScriptException ex) {
         ex.printStackTrace();
      }
   }
}