2014 pre-msc-is-6 presentation layer

Andreas Martin -

Master of Science in Business Information Systems FHNW Pre-Master Information Systems

6. Presentation Layer

Andreas Martin


http://www.flickr.com/photos/dirk_hofmann/4200450207

Andreas Martin -

Presentation Layer

Presentation layer

JavaServer Faces

Reference Project:

Lending-Reference-Project-1: Book Lending Example using JSF


Presentation Layer

http://www.flickr.com/photos/ajmexico/3281139507

The Latte Macchiato «Layering» Principle

http://www.flickr.com/photos/tf28/4367660424

Presentation Layer

Goal: Display of information, processing / forwarding of user interactions. Technologies: JavaServer Faces (JSF), JavaServer Pages (JSP), Servlets, etc.

Business (Logic) Layer

Goal: Reproduction of actions or «verbs» of the application (buy a book, print an order, deliver a book, etc.). Technologies: Enterprise Java Beans (EJBs)

Persistence Layer

Goal: Reproduction of database attributes, information or «nouns» in object / class attributes (Object-Relational Mapping, ORM). Technologies: Java Persistence API (JPA)

Andreas Martin -

Business Layer

Java EE 7 – Typical Layering including injected POJO’s


Persistence Layer

@EntityManager (JPA)

(JPA) @Entity (JPA)

Session Bean (EJB)

@PersistenceContext

Presentation Layer

Facelets (JSF) @ManagedBean (JSF)

Facelets (JSF)

Users

Databases

@EJB / @Inject

POJO

@Inject

Andreas Martin -

Java EE 7 Web Applications

Servlet {1997}:

Java classes, which creates HTML and processes HTTP- requests.

Java ServerPages (JSP) {1999}:

Quasi HTML- pages with Java code embedded.

Java ServerFaces (JSF) {v1 2004; v2 2009}:

Java ServerFaces is a web framework – the basic structure of a web application is given.

Is based on Servlets and XHTML.

JSF is a MVC (Model View Controller) architecture.

Configuration over annotations.

AJAX functionalities.


Andreas Martin -

MVC (Model View Controller) Pattern …using JSF


Adapted from: Goncalves: Code and Models licensed under a CC BY-SA 3.0 License from https://github.com/agoncal/agoncal-book-javaee7

Andreas Martin -

JSF Procedure


Web- Container

Faces Servlet

EJB

Entity

XHTML

(1) request

(6) response

(2) (3.2)

(3.1)

(4) (5)

Business Objects

(EJBs, etc.)

Controller Managed

Bean

Andreas Martin -

Controller Example – Managed Bean


Listing: BookController Managed Bean @ManagedBean @SessionScoped public class BookController { @EJB private BookEJB bookEJB; private Book book = new Book(); public String doCreateBook() { book = bookEJB.createBook(book); return "listBooks.xhtml"; } // Getters, setters

}

Enterprise JavaBean using Dependency Injection

Entity Bean

«View declaration; what is shown as next.»

Andreas Martin -

Scopes

Request-Scope (@RequestScoped ) Managed bean lives during a HTTP-request.

View-Scope (@ViewScoped ) Managed bean live as long as a corresponding view is shown..

Session-Scope (@SessionScoped ): Managed beans exists during a user holds a session.

Application-Scope (@ApplicationScoped ): One managed bean lives as long as the whole application is alive (usually

in standalone desktop applications).


@ApplicationScoped [CDI]

@SessionScoped [CDI]

@ViewScoped [JSF]

@RequestScoped [CDI]

@ConversationScoped [CDI]

Life time

Andreas Martin -

Model Example - XHTML


Listing: Snippet of an XHTML Page <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<HTML xmlns="http://www.w3.org/1999/xhtml"

xmlns:h="http://java.sun.com/jsf/html">

<h:head>

<TITLE>Creates a new book</TITLE>

</h:head>

<h:body>

<H1>Create a new book</H1>

<HR />

<h:form>

<TABLE BORDER="0">

<TR>

<TD><h:outputLabel value="ISBN : " /></TD>

<TD><h:inputText value="#{bookController.book.isbn}" /></TD>

<TR>

</TR>

<TD><h:outputLabel value="Title :" />

</TD>

<TD><h:inputText value="#{bookController.book.title}" /></TD>

</TR>

</TABLE>

<h:commandButton value="Create a book"

action="#{bookController.doCreateBook}"

styleClass="submit" />

</h:form>

<HR /> <I>APress - Beginning Java EE 6</I>

</h:body>

</HTML>

http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd






Andreas Martin -

JavaServer Faces 2.0 – DZone Refcardz


Andreas Martin -

Lending-Reference-Project-1 Book Lending Example using JSF


Andreas Martin -

Hands-on-7


Mo

de

l

View Controller

Book EJB Customer EJB

Business cases: • Create a customer including address • …CRUD…

Book Lending EJB

<Entity> Address

<Entity> Customer

<Entity> Book Lending

<Entity> Book

n 1 0..n 0..m 1

Business cases: • Lend a book • Return a book • Show all lendings

Business cases: • Create a book • …CRUD..

1

DEMO

http://www.flickr.com/photos/jurvetson/489257240

2014 pre-msc-is-6 presentation layer

Technology