JavaCro'14 - Consuming Java EE Backends in Desktop, Web, and Mobile Frontends – Geertjan Wielenga

JavaCro'14 - Consuming Java EE Backends in Desktop, Web, and Mobile Frontends – Geertjan Wielenga

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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public1 Consuming Java EE in Desktop, Web, and Mobile Frontends Geertjan Wielenga Oracle Developer Tools geertjan.wielenga@oracle.com @geertjanw
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public2 Copyright © 2012, Oracle and/or its affiliates. All rights reserved. Public Agenda  JavaScript/HTML5 Rich Client Landscape  Java EE 7  Java EE + JavaScript  Tools and Technologies  Demos
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public3 JavaScript/HTML5 Rich Clients Landscape  The thin client vs. rich client debate is pretty old… » Thin Client - All processing on server - Round tripping to server - Delays… » Thin Client Rich Client » - Complex, dynamic » - Feature-rich UI » - Access local resources
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public4 JavaScript/HTML5 Rich Clients Landscape  Server side frameworks have ruled for a while – Everything on the server  Spring / Hibernate  JSF  Struts  Tapestry  AJAX is a mild shift to the client, “best of both worlds approach” – Asynchronous partial page refresh solutions  PrimeFaces  Wicket  GWT  Vaadin
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public5 Demo: PrimeFaces, Java EE, and Maven
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public6 JavaScript/HTML5 Rich Clients Landscape
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public7 JavaScript/HTML5 Rich Clients Landscape  Rich clients powered by JS/HTML appear to be making a comeback – Improving JavaScript engines  V8  *Monkey  Nashorn – Better tools  jQuery  MV* Frameworks  Chrome, FireFox – Standards advancement  CSS3  HTML5  WebSocket
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public8 Perhaps Not A Slam Dunk?  Richer clients clearly better at some things – Highly dynamic, interactive interfaces – Complex, feature-rich UIs – “Single page applications” (“Applets” )  But perhaps not a panacea – Heavily form/workflow driven applications – Server-side rendering still a better bet for performance/reliability? – JavaScript/HTML development is not without it’s pains… – Server-side frameworks are a strong incumbent  Co-existence in the short and long term? – Islands of rich client functionality within server-centric UIs? – Different strokes for different folks?
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public9 My Big Fat Rich-Client Architecture  Very similar to client/server architecture of lore – Client responsible for UI rendering, basic input validation, logic and state – Server responsible for business logic, domain model, persistence – Web/HTTP is glue that connects client and server  Typical communication protocols – REST for majority of cases – WebSocket when full-duplex communication is needed – JavaScript tools support REST well, but not WebSocket (yet)  The typical (ideal?) data interchange format is JSON  Java EE is a great server-side platform for this architecture…
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public10 Java EE + JavaScript EJB 3 Servlet CDI JPA JAX-RS BeanValidation Java API for WebSocket Java API for JSON JMS JTA JavaScript/HTML5 JAXB JCA
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public11 JAX-RS  REST development API for Java  Server and client  Annotation based, declarative – @Path, @GET, @POST, @PUT, @DELETE, @PathParam, @QueryParam, @Produces, @Consumes  Pluggable and extensible – Providers, filters, interceptors
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public12 JAX-RS Example @Path("/atm/{cardId}") public class AtmService { @GET @Path("/balance") @Produces("text/plain") public String balance( @PathParam("cardId") String card, @QueryParam("pin") String pin) { return Double.toString(getBalance(card, pin)); } ...
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public13 Java API for WebSocket  High level declarative API for WebSocket  Both client and server-side  Small, powerful API – @ServerEndpoint, @OnOpen, @OnClose, @OnMessage, @OnError, Session, Remote  Pluggable and extensible – Encoders, decoders, sub-protocols
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public14 WebSocket Example @ServerEndpoint("/chat") public class ChatBean { Set<Session> peers = Collections.synchronizedSet(…); @OnOpen public void onOpen(Session peer) { peers.add(peer); } @OnClose public void onClose(Session peer) { peers.remove(peer); } ...
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public15 JavaScript Movers and Shakers
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public16 Demo: Backbone.js, Java EE, and Maven
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public17 Demo: Angular.js
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public18 Useful New Tools and Technologies
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public19 Useful New Tools and Technologies  Post Processors – Emmet – SASS/LESS – CoffeeScript  Cordova/PhoneGap  HTML5 Ecosystem – Grunt – Karma – Bower – Yeoman
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public20 Demo: SASS, LESS, Karma, Cordova
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public21 But Browser/Phone Is Not For Everyone…
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public22 Summary  JavaScript/HTML5 clients gaining traction as opposed to server-side web frameworks  Communication between the client and server happens via JSON over REST or WebSocket  Java EE well positioned as a JavaScript rich client backend, especially with JAX-RS, the Java API for WebSocket and JSON-P  Combining the two worlds is possible and positions applications for deployment to mobile devices  More options… more decisions… more technologies to evaluate
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  Copyright © 2012,Oracle and/or its affiliates. All rights reserved. Public23