1 Introduction to the Nashorn Engine

To invoke Nashorn in your Java application, create an instance of the Nashorn engine using the Java Scripting API.

To get an instance of the Nashorn engine:

1. Import the javax.script package.

   The Java Scripting API is composed of classes and interfaces in this package.

2. Create a ScriptEngineManager object.

   The ScriptEngineManager class is the starting point for the Java Scripting API. A ScriptEngineManager object is used to instantiate ScriptEngine objects and maintain global variable values shared by them.

3. Get a ScriptEngine object from the manager using the getEngineByName() method.

   This method takes one String argument with the name of the script engine. To get an instance of the Nashorn engine, pass in "nashorn". Alternatively, you can use any of the following: "Nashorn", "javascript", "JavaScript", "js", "JS", "ecmascript", "ECMAScript".

After you have the Nashorn engine instance, you can use it to evaluate statements and script files, set variables, and so on. The following example, EvalScript.java, provides simple Java application code that evaluates a print("Hello, World!"); statement using Nashorn.

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 Nashorn script engine
        ScriptEngine engine = factory.getEngineByName("nashorn");
        // evaluate JavaScript statement
        try {
            engine.eval("print('Hello, World!');");
        } catch (final ScriptException se) { se.printStackTrace(); }
    }
}

Java Scripting API Examples with Java Classes in Java Platform, Standard Edition Java Scripting Programmer's Guide demonstrates how to use scripts in Java code.