List available ScriptEngine

The following program list ScriptEngine(s) available in your system.

package javalistscript;

import java.util.List;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptEngineManager;

/**
 *
 * @web java-buddy.blogspot.com
 */
public class JavaListScript {

    public static void main(String[] args) {
        ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
        List<ScriptEngineFactory> listScriptEngineFactory =
                scriptEngineManager.getEngineFactories();
        for(ScriptEngineFactory factory : listScriptEngineFactory){
            System.out.println("ScriptEngine: " + factory.getScriptEngine());
            System.out.println("EngineName: " + factory.getEngineName());
            System.out.println("EngineVersion: " + factory.getEngineVersion());
            System.out.println("LanguageName: " + factory.getLanguageName());
            System.out.println("LanguageVersion: " + factory.getLanguageVersion());
            
            List<String> listExtensions = factory.getExtensions();
            for(String ext : listExtensions){
                System.out.println("Extension: " + ext);
            }
            
            List<String> listMimeTypes = factory.getMimeTypes();
            for(String mimeType : listMimeTypes){
                System.out.println("MimeType: " + mimeType);
            }
        }
    }
    
}

nashorn JavaScript exercise, call Java method from JavaScript

This example show how to call Java javaStaticMethod() in "javatestnashornjavascript.JavaTestNashornJavascript" class.

JavaTestNashornJavascript.java

package javatestnashornjavascript;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.net.URISyntaxException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

/**
 * @web http://java-buddy.blogspot.com/
 */
public class JavaTestNashornJavascript {
    
    final String myJavascript = "<path to myjavascript.js>";
    
    JavaTestNashornJavascript(){
        ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
        ScriptEngine nashorn = scriptEngineManager.getEngineByName("nashorn");

        try {
            FileReader fileReader = new FileReader(myJavascript);
            nashorn.eval(fileReader);

            Invocable invocable = (Invocable) nashorn;

            Object jsResult = invocable.invokeFunction(
                    "javascriptFunction", "Java-Buddy");
            System.out.println("result returned to Java from JavaScript: " + jsResult);

        } catch (FileNotFoundException 
                | ScriptException 
                | NoSuchMethodException ex) {
            Logger.getLogger(JavaTestNashornJavascript
                    .class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    
    public static String javaStaticMethod(String para){
        System.out.println("javaStaticMethod("+para+") called");
        String rev = new StringBuilder(para).reverse().toString();
        return rev;
    };

    public static void main(String[] args) throws URISyntaxException {
        
        JavaTestNashornJavascript javaTestNashornJavascript = 
                new JavaTestNashornJavascript();

    }

}

myjavascript.js

var javascriptFunction = function(para){
    
    print("para passed from Java to JavaScript: " + para);
    
    var myClass = Java.type("javatestnashornjavascript.JavaTestNashornJavascript");
    var revPara = myClass.javaStaticMethod(para);
    
    return "Hello " + revPara;
};

nashorn JavaScript exercise, call JavaScript function from Java

Example to call function and get result in Javascript, from Java code:

JavaTestNashornJavascript.java

package javatestnashornjavascript;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.net.URISyntaxException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

/**
 * @web http://java-buddy.blogspot.com/
 */
public class JavaTestNashornJavascript {
    
    final String myJavascript = "<path to myjavascript.js>";
    
    JavaTestNashornJavascript(){
        ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
        ScriptEngine nashorn = scriptEngineManager.getEngineByName("nashorn");

        try {
            FileReader fileReader = new FileReader(myJavascript);
            nashorn.eval(fileReader);

            Invocable invocable = (Invocable) nashorn;

            Object jsResult = invocable.invokeFunction(
                    "javascriptFunction", "Java-Buddy");
            System.out.println("result returned to Java from JavaScript: " + jsResult);

        } catch (FileNotFoundException 
                | ScriptException 
                | NoSuchMethodException ex) {
            Logger.getLogger(JavaTestNashornJavascript
                    .class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public static void main(String[] args) throws URISyntaxException {
        
        JavaTestNashornJavascript javaTestNashornJavascript = 
                new JavaTestNashornJavascript();

    }

}

myjavascript.js

var javascriptFunction = function(para){
    print("para passed from Java to JavaScript: " + para);
    return "Hello " + para;
}

more nashorn JavaScript exercise:

• Call Java method from JavaScript

Hello from java-buddy, with nashorn JavaScript Engine.

JDK 8 introduces a new Nashorn JavaScript engine written in Java, which is an implementation of the ECMAScript Edition 5.1 Language Specification. Know more by reading Java Platform, Standard Edition Nashorn User's Guide.

it's a simple example to print hello message using "nashorn" ScriptEngine.

package javatestnashornjavascript;

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

/**
 * @web http://java-buddy.blogspot.com/
 */
public class JavaTestNashornJavascript {

    public static void main(String[] args) {
        
        ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
        ScriptEngine nashorn = scriptEngineManager.getEngineByName("nashorn");
        
        try {
            nashorn.eval(
                "print('Hello from java-buddy, with nashorn JavaScript Engine.');");
        } catch (ScriptException ex) {
            Logger.getLogger(JavaTestNashornJavascript.class
                    .getName()).log(Level.SEVERE, null, ex);
        }
        
    }
    
}

more nashorn JavaScript exercise:

• Call JavaScript function from Java
• Call Java method from JavaScript