Java ScriptEngine supported languages

Question

Java has a ScriptEngine system that allows you to run/evaluate statements in a different language.
I know for a fact that JavaScript is supported, but I couldn't find any other languages to work with it.
Is, for example, Ruby implemented?

Answer 1

..I know for a fact that JavaScript is supported,..

ECMAscript, technically.

.. but I couldn't find any other languages to work with it. Is, for example, Ruby implemented?

No. The ECMAscript engine is the only one included by default, the last time I heard.

Answer 2

Here is a script to determine all languages on your system:

import java.util.List;
import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngineFactory;


public class Test {

public static void main(String[] args)
{
    ScriptEngineManager mgr = new ScriptEngineManager();
    List<ScriptEngineFactory> factories = mgr.getEngineFactories();
    for (ScriptEngineFactory factory : factories)
    {
        System.out.println("ScriptEngineFactory Info");
        String engName = factory.getEngineName();
        String engVersion = factory.getEngineVersion();
        String langName = factory.getLanguageName();
        String langVersion = factory.getLanguageVersion();
        System.out.printf("\tScript Engine: %s (%s)\n", engName, engVersion);
        List<String> engNames = factory.getNames();
        for (String name : engNames)
        {
            System.out.printf("\tEngine Alias: %s\n", name);
        }
        System.out.printf("\tLanguage: %s (%s)\n", langName, langVersion);
        }
    }

}

Hope this helps.

Answer 3

Not in ScriptEngine, but you can still use BSF. From the Apache Commons Bean Scripting Framework, you can find it's Documentation here. -

BSF 2.x supports several scripting languages currently:

• Javascript (using Rhino ECMAScript, from the Mozilla project)
• NetRexx (an extension of the IBM REXX scripting language in Java)
• Commons JEXL
• Python (using Jython)
• Tcl (using Jacl)
• XSLT Stylesheets (as a component of Apache XML project's Xalan and Xerces)

In addition, the following languages are supported with their own BSF engines:

• Java (using BeanShell, from the BeanShell project)
• Groovy
• Groovy Monkey
• JLog (PROLOG implemented in Java)
• JRuby
• JudoScript
• ObjectScript
• ooRexx (Open Object Rexx), using BSF4ooRexx.

Answer 4

There are several other languages available. For instance, Jython (Python implementation in Java). The way to use other languages is by adding the JAR file to CLASSPATH and making a reference to the right name.

For Ruby, there is JRuby. See the following: https://github.com/jruby/jruby/wiki/JavaIntegration

ScriptEngineManager m = new ScriptEngineManager();
ScriptEngine rubyEngine = m.getEngineByName("jruby");

Answer 5

The Java ScriptEngine API will work with all JSR-223 Scripting Languages. I haven't found a well documented complete list of these before but this post does a pretty good job, Where can I find a list of available JSR-223 scripting languages? Here is one list from that post,

JSR-223 script engines

• AWK
• BeanShell
• ejs
• FreeMarker
• Groovy
• Jaskell
• Java
• JavaScript
• JavaScript (Web Browser)
• Jelly
• JEP
• Jexl
• jst
• JudoScript
• JUEL
• OGNL
• Pnuts
• Python
• Ruby
• Scheme
• Sleep
• Tcl
• Velocity
• XPath
• XSLT

JSR 223 script engines maintained elsewhere

• JavaFX Script
• ABCL
• AppleScript
• Bex script
• OCaml Scripting Project
• PHP
• PHP (another one)
• Python
• Smalltalk
• CajuScript
• MathEclipse

Most have a special implementation for it to work. For example python alone will not work you need the Jython jar added to the class path. Same for Ruby you'll need JRuby.