How Scala, Wicket, and Java EE Can Improve Web Development

Copyright © 2012, Oracle and/or its affiliates. All rights reserved.
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2 How Wicket, Scala, and Java EE Can Improve Web Development Bruno Borges Oracle Product Manager for Latin America Java EE, GlassFish, WebLogic, Coherence

3 Who am I?  Java developer since 2000  Speaker at Conferences – JustJava, JavaOne Brazil, The Developers Conference, ApacheCon  Evangelized Apache Camel and Apache Wicket in Brazil  Joined Oracle on July 2012 – Product Manager for Java EE, GlassFish and WebLogic  Married, lives in Sao Paulo, has a Golden Retriever, hiker and gamer Bruno Borges

4 Agenda  All about Web Development  Apache Wicket Overview  Introducing Scala and the Gamboa Wicket DSL  Java EE for everything  The Gamboa Project

5 All About Web Development

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7 Web designing process and tools Mock, draw, code

8 PREVIEW IN THE BROWSER

9 All about Web Development  There are two ways to build web applications – bottom-up  Mock up interfaces, develop using a web framework, apply design – top-down  Design pixel-perfect prototype, adapt prototype to a web framework,  There’s no web framework able to do both… productively speaking  Pixel-perfect websites vs functional websites How do we build web sites and applications?

10 Outside the Java Web Framework Land  Ruby on Rails  PHP  Python – Django Framework  JavaScript + REST – ExtJS – jQuery What are the technologies people use to build pixel-perfect sites?

11 What about functional websites?  Java Server Faces  GWT, Vaadin  Apache Wicket  others  Better use the bottom up design strategy Component-based frameworks work better

12 Java Frameworks for Pixel Perfect Websites  JSP / Servlets  Struts 2, Tapestry, Wicket  Java Server Faces, specifically Facelets  Play!, Lift  others  Better use the top down design strategy Frameworks that are good for pixel-perfect websites

13 What if we could have a framework that doesn’t force us to totally modify the work of a Web Designer for prototype?

14 Imperative vs Declarative HTML Markup  Pixel-perfect websites are always top-down – A lot of work to add server-side code to the prototype – And it would be good for web designers to continue to have a functional prototype after server-side code is added  Imperative – Must change from raw HTML markup to specific web framework markup  Declarative – Annotates markup to be accessed, and modified, later by the framework What is the best HTML markup for pixel-perfect websites?

15 Before <form action=”save”> <input type=”text” name=”name” /> <input type=”submit” value=”Save” /> </form> After, using Apache Struts <s:form action=”save”> <s:input property=”name” /> <s:submit value=”Save” /> </s:form> Imperative Markup

16 Does it run on the browser?  Imperative frameworks that modify the prototype – Web designers loose ability to preview in the browser – They must install, configure and run  Servlet containers, Ruby, or PHP servers  You really don’t want web designers touching server-side code  Specially programmers modifying HTML or CSS elements to fix things Not really…

17 Before <form action=”save”> <input type=”text” name=”name” /> <input type=”submit” value=”Save” /> </form> After, using Apache Wicket <form wicket:id=”form”> <input type=”text” wicket:id=”name” /> <input type=”submit” value=”Save” wicket:id=”save” /> </form> Declarative Markup

18 Programmers and Developers  Programmers focused on server-side programming  Web Designers able to modify client-side without messing server-side  Preview in the browser  Customer happy to see (statically) how the application is progressing – Open Firefox, go to file:///home/customer/project/web/index.html Happily Ever After…

19 Apache Wicket Quick overview

20 HTML Prototype /MyHomePage.html <html> <head><title>Apache Wicket</title></head> <body> <span>some message</span> <form> Name: <input type=”text” /> Email: <input type=”text” /> <input type=”submit” value=”Send” /> </form> </body> </html> The final product from the Web Designer

21 HTML Prototype /MyHomePage.html <html> <head><title>Apache Wicket</title></head> <body> <span wicket:id=”msg”>some message</span> <form wicket:id=”form”> Name: <input type=”text” wicket:id=”name” /> Email: <input type=”text” wicket:id=”email” /> <input type=”submit” value=”Send” /> </form> </body> </html> The final product from the Web Designer

22 Java side /MyHomePage.java public class MyHomePage extends WebPage { public HomePage() { add(new Label(“msg”, “JavaOne”)); Form form = new Form(“form”) { public void onSubmit() { usrBean.salvar(getModelObject()); }}; form.add(new TextField(“name”)); form.add(new TextField(“email”)); form.setModel(new CompoundPropertyModel(new User())); add(form); } } Where all the magic happens, object oriented

23 Gmap2 gmap = new Gmap2(“map”); page.add(gmap); <div wicket:id=”map”> Google Maps </div> Easily Extensible  Just add the JAR with extra components to the classpath

24 Apache Wicket  jQuery as its client-side engine for – Core components – Ajax – WebSockets  Page composition by: Inheritance, Borders and Panels  Integration with CDI  Back button support  Several components, and also the WicketStuff Community And so many other features

25 Scala Language

26 Scala Language  Object Oriented and Functional Language  Runs on JVM  Statically typed  Compiles to Java byte code (sweeeet)  Extensible  Easy to define custom DSLs Quick introduction var foo = 8 foo = “bar” Type mismatch; found: String(“bar”) required: Int

27 Scala Language  They are objects as well val func = () ⇒ println(“functional programming”) def callF(paramF: () ⇒ Unit) = paramF() callF(func) Functions

28 Scala Language  They may seem complex, but you get used to them val list1to9 = 1 to 9 toList for (i ← list1to9) { print(i) } list1to9.foreach(i ⇒ print(i)) Very smart constructions

29 Scala Language val listA = List(1, 2) val listB = List(3, 4) val listC = listA :: listB // listC is a new List object val listD = listC :: 5 print(listD) // output: List(1,2,3,4,5) Very smart constructions

30 Scala Language val map = new HashMap[Int, String] map += 1 → "Number 1" map += 2 → "Number 2" map += 3 → "Number 3" println(map(2)) // '2' is the key, not the index! val romans = Map(1 → "I", 2 → "II", 3 → "III", 4 → "IV", 5 → "V") println(romanNumeral(4)) // outputs: "IV" Very smart constructions

31 Back to Wicket  Wicket programming model resembles Swing  Pushes developers to use anonymous, inner classes  Functional programming fits quite well into this model  Less code, less verbosity  Scala #win Strong use of anonymous classes

32 Wicket + Scala: perfect combination /MyHomePage.java public class MyHomePage extends WebPage { @Inject private MyService service; public MyHomePage() { add(new Label(“msg”, “JavaOne”)); Form form = new Form(“form”, new CompoudPropertyModel(new User())){ public void onSubmit() { service.update(getModelObject()); } }; form.add(new TextField(“name”)); form.add(new TextField(“email”)); add(form); } } Before, in Java

33 Wicket + Scala: perfect combination /MyHomePage.scala class MyHomePage extends WebPage { @Inject var service: MyService = _ add(new Label(“msg”, “JavaOne”)) object form extends Form(“form”, new CompoundPropertyModel(new User())) { add(new TextField(“name”)) add(new TextField(“email”)) override def onSubmit() = { service.update(getModelObject()) } } add(form) } Now, with Scala

34 Wicket + Scala: perfect combination /MyHomePage.scala class MyHomePage extends WebPage with DSLWicket { @Inject var service: MyService = _ label(“msg”, “JavaOne”) val f = form(“form”, () ⇒ service.update(f.mobject)) f.scmodel(new User()) f.textField[String](“name”) f.textField[String](“email”) } Now with specific Scala DSL for Wicket

35 Java EE for everything else

36 Java EE 6  Enterprise Java Beans  Contexts and Dependency Injection  Java Persistent API  Java Transaction API  Bean Validation  JAX-RS Filling the necessary gaps, extraordinarily well

37 And more stuff  GlassFish Maven Embedded Plugin  Derby DB  No more web.xml – Servlet 3.0 is awesome  Getters/Setters generated – Scala’s @BeanProperty annotation Like…

38 No more web.xml package code.webapp import javax.servlet.annotation.{ WebFilter, WebInitParam } import org.apache.wicket.protocol.http.WicketFilter @WebFilter(value = Array("/*"), initParams = Array( new WebInitParam(name="applicationClassName", value="code.webapp.Application"), new WebInitParam(name="filterMappingUrlPattern", value = "/*“) )) class GamboaApplication extends WicketFilter Servlet 3 and Scala

39 Getters/Setters generated package code.data import scala.reflect.BeanProperty import javax.persistence.{ Id, GeneratedValue } trait Identifiable extends Serializable { @Id @GeneratedValue @BeanProperty var id: String = _ } Scala’s @BeanProperty annotation

40 Getters/Setters generated package code.data import scala.reflect.BeanProperty import javax.persistence.{ Entity, Table } @Entity @Table(name = “USERS”) class User extends Identifiable { @BeanProperty var name: String = _ @BeanProperty var email: String = _ } Scala’s @BeanProperty annotation

41 Gamboa Project Great architecture, written an archetype must be! Apache Wicket + Java EE 6 + Scala Gamboa Project www.gamboa-project.org

42 Gamboa Project  Scala DSL for Wicket  3 archetypes – Java EE archetype  JPA, CDI, EJB3, GlassFish Maven Plugin integrated – Spring with CouchDB – Spring with MongoDB  Both integrated with Jetty plugin  Directory structure simplified for Web development – Not really “Maven convention”, for good reason Maven archetypes

44 Gamboa Demo Group Birthday

45 Next time you choose a web framework, think not only about features, but also about the web development process and the type of website you are going to build.

46 QUESTIONS?

47 THANK YOU! @brunoborges blogs.oracle.com/brunoborges

48 The preceding is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle.

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How Scala, Wicket, and Java EE Can Improve Web ...

How Scala, Wicket, and Java EE Can Improve Web Development

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