Java EE 8 Web Frameworks: A Look at JSF vs MVC

1. Java EE 8 Web Frameworks A Look at JavaServer Faces vs MVC Josh Juneau

2. About Me • Member of JSF 2.3 (JSR 372) EG • Member of JSR 378 (Portlet 3.0 Bridge) EG • Developer/Analyst/DBA @ Fermilab • Apress Author • OTN/Java Magazine Contributor • Member of CJUG • Java EE Guardians

3. Agenda • Overview of JavaServer Faces & Demo • Overview of MVC & Demo • Feature Comparison • JSF 2.3 Feature Overview • Java EE 8 Overall Status

4. MVC Architecture • Model = Data • View = UI • Controller = Business Logic

5. JavaServer Faces Overview JavaServer Faces technology establishes the standard for building server-side user interfaces for Java EE. • An API for representing UI components and managing their state; handling events, server-side validation, and data conversion; deﬁning page navigation; supporting internationalization and accessibility; and providing extensibility for all these features • JavaServer Faces (JSF) custom tag libraries for expressing UI components within a view and for wiring components to server-side objects

6. JavaServer Faces Overview The well-deﬁned programming model and tag libraries signiﬁcantly ease the burden of building and maintaining web applications with server-side UIs. With minimal effort, you can: • Drop components onto a page by adding component tags • Wire component-generated events to server-side application code • Bind UI components on a page to server-side data • Construct a UI with reusable and extensible components • Save and restore UI state beyond the life of server requests

7. JSF Models Data tier to work with entity classes (POJOs that map to database tables) to work with the underlying database from within a Java EE application. • EJBs…no…not J2EE!!!! • JAX-RS

8. JSF Views • Tree of Components • Facelets or HTML • Expression Language • Mix with JSTL and other tab libraries, as needed • Component Libraries

9. JSF Views

10. JSF Data Validation • Bean Validation • Faces Validator

11. JSF Controllers • Business logic - FacesServlet • CDI Scopes…No More JSF @ManagedBean • SessionScoped, ApplicationScoped, ViewScoped, RequestScoped, ConversationScoped, FlowScoped, Dependent, Singleton • Contextual…State Managed Across Requests

12. JSF Typical Form Submit Procedure • User completes form entry by populating form components. • User clicks a commandButton, which invokes a server-side method, and the CDI bean values are submitted to FacesServlet for processing. • Action method performs its work and then returns control to FacesServlet for navigation.

13. JSF Lifecycle • Restore View Phase • Apply Request Values Phase • Process Validations Phase • Update Model Values Phase • Invoke Application Phase • Render Response Phase

14. JSF Lifecycle

15. JSF Ajax Support • f:ajax for invoking server-side functionality • Many third-party UI frameworks

16. JSF JSF in Action!

17. JSR 371: MVC 1.0 https://ozark.java.net/ • Action-oriented framework layered on top of JAX-RS • Manual controller logic…you control your own destiny! • No UI Components • You choose your front end technology

18. MVC 1.0 Models Utilize entity classes for data, or store into CDI bean Two ways to work with models: • javax.mvc.Models class • CDI-Based Models

19. MVC 1.0 Views ViewEngine Used to Merge Model and View • Utilize a number of different view technologies • Ozark Ships with 3 Implementations • Views reside within WEB-INF/views folder

20. MVC 1.0 Views

21. MVC 1.0 Validating Data • Manual Validation • Bean Validation

22. MVC 1.0 Controllers • Controls the request-processing for an MVC application. • JAX-RS Implementation • Class annotated with @Controller either at class level or method level. • Must be CDI Managed • Possible to create hybrid classes (@Controller at method level)

23. MVC 1.0 Controllers • Four return types: String, void, Response, Viewable • String: returns path to view • void: requires @javax.mvc.View annotation • Response: typical javax.ws.rs.core.Response, providing access to the response • Viewable: javax.mvc.Viewable containing information ab the view and how to process • Default response type text/html, but can be modiﬁed with @Produces

24. MVC 1.0 Controllers

25. MVC 1.0 Views to Controllers - Parameters Parameters handled via annotations in Controller: • @PathParam: Used to extract path parameters • @FormParam: Used to process ﬁelds from form • @QueryParam: Used when parameters appended to URL • @BeanParam: Used to inject various request parameters into a bean

26. MVC 1.0 Views - Redirecting Responses • JAX-RS return Response.seeOther(URI.create(“redirectView”)).build() • MVC return “redirect:redirectView” @RedirectScoped Annotation • Bean will span at most two requests • Must be Serializable

27. MVC 1.0 Exception Handling • Can be applied via try/catch at method level or globally return Response.status(BAD_REQUEST).entity("error.jsp").build(); • ExceptionMapper class

28. MVC 1.0 Security • Utilize ${mvc.csrf.name} and ${mvc.csrf.token} in form • javax.mvc.security.CsrfProtection property • @CsrfValid Annotation at Method Level

29. MVC 1.0 MVC in Action!

30. JSF or MVC? JSF MVC • Component Based • Controller Logic Automates Processing • Facelets • Rapid Development • Works well with REST • Stateful…remains across requests • Action Based • Layered on Top of JAX-RS • Manual Validations/ Conversions • Many Different View Options • Fine Control Request/ Response • Great ﬁt for REST • No State Across Requests

31. JSR 372: JSF 2.3 Not forgotten with Java EE 8 While scope of update is not very large, new features and enhancements will help continue making JSF relevant in today’s world. Thanks to the OmniFaces folks for adding a number of features to JSF.

32. JSF 2.3 in Java EE 8 • Two feature drivers: Oracle & Community • Feature clean-up • Small new feature set based upon community requests • Mature standard for building Java EE applications

33. JSF 2.3 - Oracle Focus Tie up loose ends: • Speciﬁcation clariﬁcations • CDI Alignment • Others Small Scale New Features: • CDI Managed Beans Only • Ajax Method Invocation • Multi-component Validation

34. JSF 2.3 - Community Focus • JSON Ajax Component Rendering • Stateless enhancements • GET Enhancements • Push Support

35. JSF 2.3 New Features (Implemented) • Inject ViewMap @ViewMap @Inject Map viewMap; • Inject UiViewRoot @Inject UIViewRoot viewRoot; • #1332 - Let CDI handle #{view} • #1331 - Let CDI handle #{application} • #1254 - contracts attribute too restrictive.

36. JSF 2.3 New Features (Implemented - ctd) • #1328 - Let CDI handle #{session} EL resolving • #1325 - Let CDI handle #{applicationScope} • #1311 - Let CDI handle #{facesContext} EL resolving • #1323 - Support @Inject for the applicationMap @ApplicationMap @Inject Map applicationMap; • #1322 - Simplify #{externalContext} to use ExternalContextProducer

37. JSF 2.3 New Features (Implemented - ctd) • #1309 - Support @Inject for ExternalContext @Inject ExternalContext externalContext; • #527 - Support @Inject for FacesContext @Inject FacesContext facesContext; • javax.faces.bean.ManagedProperty Replacement

38. JSF 2.3 New Features (Implemented - ctd) • #1396 - f:socket for SSE and WebSocket http://jj-blogger.blogspot.com/2016/02/a-look-at- upcoming-jsf-23-push-support.html

39. Learn More

40. What Is The CJUG? Chicago Java Users Group is dedicated to the helping you learn and network. • Technology community second to none. • Learn and contribute to Java / JVM ecosystem • Mentorship and career opportunities • Have fun and build cool things

41. Java EE Guardians Join us and help move Java EE into the future!

42. Contact Josh Juneau - Java EE 7 Recipes - Introducing Java EE 7 - JavaServer Faces: Introduction By Example - Java 8 Recipes Twitter: @javajuneau

43. Read On!