JavaScript Evented I/O & moreJavaScript Evented I/O & morefor the Java Enterprise Ecosystemfor the Java Enterprise Ecosystem

Niko Köbler ( )@dasniko{JavaScript}Training

Node.js on the JVMNode.js on the JVM

http://www.javascript-training.net/

I'm to hire!I'm to hire!

What is Node.js?What is Node.js?Server-side JavaScript platform built on Google V8engineWhat JavaScript has done for the webbrowser, Node.js is doing for the backend server

Asyncronous, non-blocking, evented I/O with JavaScript

http://nodejs.org

var http = require('http');http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n');}).listen(1337, '127.0.0.1');console.log('Server running at http://127.0.0.1:1337/');

The Event LoopThe Event Loop

The cost of I/OThe cost of I/OL1-cache 3 cyclesL2-cache 14 cyclesRAM 250 cyclesDisk 41 000 000 cyclesNetwork 240 000 000 cycles

Why JavaScript?Why JavaScript?“ (undefined is not a function!)

Why Java?Why Java?

With Java, we have...With Java, we have...Longterm investmentsMature solutionsComplex and extensive business logicIntegration of heterogeneous environmentsacross platformsBlueprints and best-practices availableProven infrastructure and monitoring options

And now,And now,you wanna tell us about thisyou wanna tell us about this"brave""brave" new (Node-)world? new (Node-)world?

Mostly new applicationsMostly No-SQL backedNew application approachesMore focused silo apps"Cool stuff"~ 120.000 NPM libraries available (01/2015)

No enterprise integration (yet)Infrastructure? Monitoring? Operations?

Speaking JavaScriptSpeaking JavaScript“ Like it or not, JavaScript is everywhere these days - frombrowser to server to mobile - and now you, too, need to

learn the language or dive deeper than you have.Dr. Axel Rauschmayer

http://speakingjs.com

“ In four years ... Node.js has experienced phenomenalgrowth. Node.js is the language of choice for high

performance, low latency applications and has beenpowering everything from robots to API engines to cloud

stacks to mobile web sites.Node.js Advisory Board - October 23, 2014

IntegrationIntegration

IntegrationIntegration

dynamicdynamicinvokeinvoke

NashornNashornJavaScript Enginge on the JVMbased on invokedynamic featurecompetes with Google V8ECMAScript 5.1 compatible (ES6/ES2015 with Java 9)Seamless interoperability of Java and JavaScriptShell ScriptingWith Java 8u40 native execution of TypeScriptLanguage and API Extensions

http://openjdk.java.net/projects/nashorn/

closures, collections & for each, multi-line string literals, string interpolation, __noSuchProperty__,__noSuchMethod__, typed arrays, binding properties, error extensions, conditional catch clause,String functions, and many, many more...

Java and JavaScriptJava and JavaScript“ ...are similar than car and carpet are similar.

NashornNashornCommand Line Client

$ $JAVA_HOME/bin/jjsjjs> print('Hello Nashorn!');

Invoking JavaScript from JavaScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");engine.eval("print('Hello Nashorn!');");

engine.eval(new FileReader("scriptfile.js"));

Invocable invocable = (Invocable) engine;Object result = invocable.invokeFunction("jsSayHello", "Nashorn");

NashornNashornInvoking Java from JavaScript

package my.package;public class MyJavaClass { static String sayHello(String name) { return String.format("Hello %s from Java!", name); }}

var MyJavaClass = Java.type('my.package.MyJavaClass');var result = MyJavaClass.sayHello('Nashorn');print(result); // Hello Nashorn from Java!

NashornNashornListing Docker Containers via REST-Call

#!/usr/bin/jjs -fvvar host = "DOCKER_HOST"var dockerUri="http://${host}:5555/containers/json";var command = "curl ${dockerUri}";$EXEC(command);var containers = JSON.parse($OUT);for each(container in containers){ print("${container.Image} / ${container.Names[0]} / ${container.Status}");}

(by )Adam Bien

AvatarAvatarThe Oracle solutionThe Oracle solution

††

Avatar 2.0Avatar 2.0

Inter-thread communicationMessage BusShared State (Map API: Key-Value-Store)

Model-Store-APIJPA (Eclipselink) / JDBC based

https://avatar.java.net

Avatar 2.0Avatar 2.0

The RedHat counter The RedHat counter

developed by project:odd at RedHatbased on DynJS (Nashorn is on its way!)"more JavaScript than Node.js"Netty for async I/OVert.x integration/interaction

http://nodyn.io

also based on invokedynamicREPL / command lineJava interaction / embedding

http://dynjs.org

“ Netty is an asynchronous event-driven networkapplication framework for rapid development of

maintainable high performance protocol servers & clients.

http://netty.io

NettyNetty

Node.js ArchitectureNode.js Architecture

Nodyn ArchitectureNodyn Architecture

Embed in Java programsEmbed in Java programspublic class EmbedExample {

private static final String SCRIPT = "" + "var main = require('./project/main.js');" + "main.run();";

public void runMain(String... args) throws InterruptedException { // Use DynJS runtime RuntimeFactory factory = RuntimeFactory.init( EmbedExample.class.getClassLoader(), RuntimeFactory.RuntimeType.DYNJS);

// Set config to run main.js NodynConfig config = new NodynConfig( new String[] { "-e", SCRIPT } );

// Create a new Nodyn and run it Nodyn nodyn = factory.newRuntime(config); nodyn.setExitHandler( new NoOpExitHandler() ); try { int exitCode = nodyn.run(); if (exitCode != 0) { throw new TestFailureException(); } } catch (Throwable t) { throw new TestFailureException( t ); } }}

“ Vert.x is a lightweight, high performance applicationplatform for the JVM that's designed for modern mobile,

web, and enterprise applications.

Polyglott*SimplicityScalabilityConcurrencyDistributed Event Bus**

http://vertx.io

*) Java, JavaScript, Ruby, Groovy, Python, Scala, Clojure, Ceylon**) using Hazelcast In-Memory Data Grid ( )hazelcast.org

vertx2-corevertx2-coreThis module exposes the vert.x 2.x eventbus to node.js clients.

https://github.com/nodyn/vertx2-core

mod-nodynmod-nodynThis supports running Node.js workloads inside of Vert.x.

https://github.com/nodyn/mod-nodyn

Beer-as-a-ServiceBeer-as-a-Servicehttps://github.com/dasniko/beer-as-a-service

var http = require("http");var vertx = require("vertx2-core");

var registration = vertx.eventbus.register("bar", function(message) { var amount = message.body.amount; console.log("BAR: Someone ordered " + amount + " beer(s)."); message.reply({wait_time: amount * 1.75});});

var server = http.createServer(function(request, response) { var parts = request.url.split("/"); var amount = parts[1];

vertx.eventbus.send("bar", {amount: amount}, function(message) { response.write(amount + " beer(s) will be ready in " + message.body.wait_time + " minutes"); response.end(); });});

server.listen(9000, function() { console.log( "Beer-Server is listening on port 9000" );});

beer-as-a-service.js

run with nodyn

var http = require("http");var vertx = require("vertx2-core");

var server = http.createServer(function(request, response) { var parts = request.url.split("/"); var amount = parts[1];

vertx.eventbus.send("bar", {amount: amount}, function(message) { response.write(amount + " beer(s) will be ready in " + message.body.wait_time + " minutes"); response.end(); });});

server.listen(9000, function() { console.log( "Beer-Server is listening on port 9000" );});

beer-web.js

beer-bar.jsvar eventBus = require("vertx/event_bus");

eventBus.registerHandler("bar", function(message, replier) { java.lang.System.err.println("BAR: Someone ordered " + message.amount + " beer(s)"); replier({wait_time: message.amount * 1.75});});

java.lang.System.err.println("The BAR is open!");

run with vertx in cluster mode

ConclusionConclusionJavaScript is an emerging language and widely adoptedNode.js / IO.js is very popularOperations, monitoring and integration lacksJVM is Enterprise environment of choice(and all the above lacks are already solved)Run JavaScript on the JVM thanks to invokedynamic(Nashorn, DynJS)Re-use your infrastructures and libraries with NodeNodyn from Red Hat

Re-use of Node API module, integration of Netty and Vert.xProcess-bindings in Java/JavaScriptEmbed Node.js apps into your Java applications

Thank you!Thank you!

Questions?Questions?

Contact:

@dasnikoniko@n-k.de

http://slides.com/dasniko/nodejs-jvm