Chapter 17: Enterprise Java Case Study: Architectural Overview

2002 Prentice Hall. All rights reserved.

Chapter 17: Enterprise Java Case Study: Architectural Overview

Outline17.1 Introduction17.2 Deitel Bookstore17.3 System Architecture17.4 Enterprise JavaBeans

17.4.1 Entity EJBs17.4.2 Stateful Session EJBs

17.5 Servlet Controller Logic17.6 XSLT Presentation Logic


17.1 Introduction

• Online bookstore e-business application– Servlets– EJBs– XML– XSLT – MVC architecture


17.2 Deitel Bookstore

• Case study– Implement functionality for commercial on-line store

• Provide product catalog• Provide shopping cart• Provide customer registration• Allow customers to view previous orders• Provide functionality for several clients

– Standard Web browsers– WML browsers– cHTML browsers


17.3 System Architecture

• Multi-tier application– Information tier

• Maintains data for application (RDBMS)– Middle tier

• Implements business logic and controller logic– Control interactions between information and client tiers

– Client tier• Application’s user interface (e.g., Web browser)


17.3 System Architecture (cont.)

Applic ation Server

Middle Tier Info rmation TierClient Tier

RDBMS

Fig. 17.1 Three-tier application model in Deitel Bookstore.


17.3 System Architecture (cont.)

Middle Tier

Servlet Conta iner

Web Server

Servlets implement the applic ation’s contro ller and communicate with EJ Bs using RMI-IIOP.

XML

Clients communicate with the Web server, which fo rwards requests to the servlets running in the applic ation server’s servlet container.

XSLTransformer(cHTML)

XSL

WAPClient

WebBrowser

Client Tie ri-modeC lient

RDBMS

Information Tier

The information tier and EJ Bs fo rm the applic ation’s model.

EJ B EJ BEJ BEJ B C ontainer

Servlet

RMI-IIOP

Appli

catio

n Ser

ver

XML

XSLTransformer(XHTML)

XSL

Servlet

XML

XSLTransformer(WML)

XSL

Servlet

J DBC

XSL transformations implement the application’s view, customizing content for eac h client type.

The EJ B container provides run-time services to the EJ Bs, such as database connections, and life -c ycle management.

The servlet container manages servle t life -cycles and communic ation with the Web server.

Fig. 17.2 Detailed architecture of Deitel Bookstore Enterprise Java case study.


17.4 Enterprise JavaBeans

• EJBs– Implement business logic and database abstraction layer– Stateful session EJB

• Represents a customer’s shopping cart– Entity EJB

• Provide object-based interface to information tier

• Servlets– Use EJB business logic to create an on-line store


17.4.1 Entity EJBs

• Entity EJB– Provide object-based interface to information tier– Represents object stored in application’s relational database

• Class Customer stores– First name– Last name– Billing address– Shipping address– Credit-card information

• Class Product


17.4.1 Entity EJBs (cont.)

• Entity EJB– Each entity EJB has corresponding model class

• Has properties for each entity EJB property• e.g., Product EJB has corresponding ProductModel

– ProductModel has properties for• Product ISBN• Product price• Product author


17.4.2 Stateful Session EJBs

• ShoppingCart– Stateful session EJB– Manages customer’s shopping cart– Primary business-logic component in Deitel Bookstore


17.5 Servlet Controller Logic

• Servlets– Middle-tier interface between client and business logic– Implement the controller in MVC architecture– Interact with EJB business-logic components

• Handle client requests (via HTTP and WAP)• Process data as XML documents• Pass XML documents through XSL transformations

– Produce presentation for each client


17.6 XSLT Presentation Logic

• Generate appropriate presentation for each client– Each servlet employs XSL Transformer and XSLTs

• One XLST for producing XHTML• One XLST for producing WML• One XLST for producing cHTML

2002 Prentice Hall.All rights reserved.

Outline

Fig. 17.3 XML file generated by Get-ProductServlet.

Lines 1-14

1 <?xml version="1.0" encoding="UTF-8"?>2 <catalog>3 <product>4 <isbn>0130284173</isbn>5 <publisher>Prentice Hall</publisher>6 <author>Deitel, Deitel, Nieto, Lin & Sadhu</author>7 <title>XML How to Program</title>8 <price>$69.95</price>9 <pages>1200</pages>10 <image>images/xmlhtp1.jpg</image>11 <media>CD</media>12 <quantity>500</quantity>13 </product>14 </catalog>

XML document marks up a product, including the product’s ISBN, title,

author, publisher and price


Outline

Fig. 17.4 XSL transformation for generating XHTML from GetProduct-Servlet (part 1).

Lines 1-92

1 <?xml version = "1.0"?>2 3 4 5 6 7 <xsl:stylesheet version = "1.0"8 xmlns:xsl = "http://www.w3.org/1999/XSL/Transform">9 10 <xsl:output method = "xml" omit-xml-declaration = "no" 11 indent = "yes" doctype-system = "DTD/xhtml1-strict.dtd"12 doctype-public = "-//W3C//DTD XHTML 1.0 Strict//EN"/>13 14 15 <xsl:include href = "/XSLT/XHTML/error.xsl"/>16 17 18 <xsl:template match = "product">19 <html xmlns = "http://www.w3.org/1999/xhtml" 20 xml:lang = "en" lang = "en">21 22 <head>23 <title>24 <xsl:value-of select = "title"/> -- Description25 </title>26 27 <link rel = "StyleSheet" href = "styles/default.css"/>28 </head>29 30 <body>31 32 33 <xsl:for-each select = 34 "document( '/XSLT/XHTML/navigation.xml' )">35 <xsl:copy-of select = "."/>

Extract relevant pieces of information from the XML

document to create appropriate XHTML representation


Outline


36 </xsl:for-each>37 38 <div class = "header">39 <xsl:value-of select = "title"/>40 </div>41 42 <div class = "author">43 by <xsl:value-of select = "author"/>44 </div>45 46 47 <div class = "productDetails">48 <table style = "width: 100%;">49 <tr>50 <td style = "text-align: center;">51 <img class = "bookCover" 52 src = "images/{image}"53 alt = "{title} cover image."/> 54 </td>55 56 <td>57 <p style = "text-align: right;">58 Price: <xsl:value-of select = "price"/>59 </p>60 61 <p style = "text-align: right;">62 ISBN: <xsl:value-of select = "ISBN"/>63 </p>64 65 <p style = "text-align: right;">66 Pages: <xsl:value-of select = "pages"/>67 </p> 68


Outline


69 <p style = "text-align: right;">70 Publisher: 71 <xsl:value-of select = "publisher"/>72 </p>73 74 75 <form method = "post" action = "AddToCart">76 <p style = "text-align: center;">77 <input type = "submit" 78 value = "Add to cart"/>79 80 <input type = "hidden" name = "ISBN" 81 value = "{ISBN}"/>82 </p>83 </form>84 </td>85 </tr>86 </table>87 </div>88 89 </body>90 </html>91 </xsl:template>92 </xsl:stylesheet>


Outline

Fig. 17.5 XHTML document generated by XSLT in Get-ProductServlet (part 1).

1 <?xml version="1.0" encoding="UTF-8"?>2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 3 "DTD/xhtml1-strict.dtd">4 <html xmlns="http://www.w3.org/1999/xhtml" 5 lang="en" xml:lang="en">6 <head>7 <title>XML How to Program -- Description</title>8 <link href="styles/default.css" rel="StyleSheet" />9 </head>10 <body>11 <div>12 <div class="logo">13 <table style="width: 100%;">14 <tr>15 <td style="text-align: left;">16 <img src="images/logotiny.gif" 17 alt="Deitel & Associates, Inc. logo." />18 </td>19 20 <td style="text-align: right;">21 <div style=22 "position: relative; bottom: -50px;">23 <form action="ProductSearch" method="get">24 <p><input type="text" size="15"25 name="searchString" />26 <input type="submit" value="Search" />27 </p>28 </form>29 </div>30 </td>31 </tr>32 </table>33 </div>34


Outline


35 <div class="navigation">36 <table class="menu">37 <tr>38 <td class="menu">39 <a href="GetAllProducts">Product Catalog</a>40 </td>41 42 <td class="menu">43 <a href="registration.html">Create Account</a>44 </td>45 46 <td class="menu">47 <a href="login.html">Log in</a>48 </td>49 50 <td class="menu">51 <a href="ViewCart">Shopping Cart</a>52 </td>53 54 <td class="menu">55 <a href="ViewOrderHistory">Order History</a>56 </td>57 </tr>58 </table>59 </div>60 61 </div>62 <div class="header">XML How to Program</div>63 <div class="author">64 by Deitel, Deitel, Nieto, Lin & Sadhu</div>65 <div class="productDetails">66 <table style="width: 100%;">67 <tr>68 <td style="text-align: center;">


Outline


69 <img alt="XML How to Program cover image." 70 src="images/xmlhtp1.jpg" 71 class="bookCover" /></td>72 <td>73 <p style="text-align: right;">74 Price: $69.95</p>75 <p style="text-align: right;">76 ISBN: 0130284173</p>77 <p style="text-align: right;">78 Pages: 1100</p>79 <p style="text-align: right;">80 Publisher: Prentice Hall</p>81 82 <form action="AddToCart" method="post">83 <p style="text-align: center;">84 <input value="Add to cart" 85 type="submit" />86 <input value="0130284173" 87 name="ISBN" type="hidden" /></p>88 </form>89 </td>90 </tr>91 </table>92 </div>93 </body>94 </html>


Outline



Outline

Fig. 17.6 XSL transformation for generating WML from GetProduct-Servlet (part 1).

Lines 1-54

1 <?xml version = "1.0"?>2 3 <xsl:stylesheet version = "1.0"4 xmlns:xsl = "http://www.w3.org/1999/XSL/Transform">5 6 <xsl:output method = "xml" omit-xml-declaration = "no" 7 doctype-system = "http://www.wapforum.org/DTD/wml_1.1.xml"8 doctype-public = "-//WAPFORUM//DTD WML 1.1//EN"/>9 10 <xsl:include href = "/XSLT/WML/error.xsl"/> 11 12 <xsl:template match = "product">13 <wml>14 15 <card id = "product" title = "{title}">16 <do type = "accept" label = "Add To Cart">17 <go href = "AddToCart" method = "post">18 <postfield name = "ISBN" value = "{ISBN}"/>19 </go>20 </do>21 22 <do type = "prev" label = "Back">23 <prev/>24 </do>25 26 <p>Description:</p>27 <p><xsl:value-of select = "title"/></p>28 <p>by <xsl:value-of select = "author"/></p>29 30 <p>31 <table columns = "2" title = "info">32 <tr>33 <td>ISBN: 34 <xsl:value-of select = "ISBN"/>35 </td>


document to create appropriate WML representation


Outline

Fig. 17.6 XSL transformation for generating WML from GetProduct-Servlet (part 2).

36 <td>Price: 37 $<xsl:value-of select = "price"/>38 </td>39 </tr>40 <tr>41 <td>Publisher: 42 <xsl:value-of select = "publisher"/>43 </td>44 <td>Pages: 45 <xsl:value-of select = "pages"/>46 </td>47 </tr>48 </table>49 </p>50 </card>51 52 </wml>53 </xsl:template>54 </xsl:stylesheet>


Outline

Fig. 17.7 WML document generated by XSLT in Get-ProductServlet (part 1).

Lines 1-29

1 <?xml version="1.0"?>2 <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" 3 "http://www.wapforum.org/DTD/wml_1.1.xml">4 5 <wml>6 <card title="XML How to Program" id="product">7 <do label="Add To Cart" type="accept">8 <go method="post" href="AddToCart">9 <postfield value="0130284173" name="ISBN"/></go>10 </do>11 <do label="Back" type="prev"><prev/></do>12 13 <p>Description:</p>14 <p>XML How to Program</p>15 <p>by Deitel, Deitel, Nieto, Lin & Sadhu</p>16 <p>17 <table title="info" columns="2">18 <tr>19 <td>ISBN: 0130284173</td>20 <td>Price: $$69.95</td>21 </tr>22 <tr>23 <td>Publisher: Prentice Hall</td>24 <td>Pages: 1100</td>25 </tr>26 </table>27 </p>28 </card>29 </wml>

WML document contains little formatting information, because display capabilities are limited


Outline

Fig. 17.7 WML document generated by XSLT in Get-ProductServlet (part 2).


Outline

Fig. 17.8 XSL transformation for generating cHTML from GetProduct-Servlet (part 1).

Lines 1-78

1 <?xml version = "1.0"?>2 3 <xsl:stylesheet version = "1.0"4 xmlns:xsl = "http://www.w3.org/1999/XSL/Transform">5 6 <xsl:output method = "html" 7 omit-xml-declaration = "yes" 8 indent = "yes" 9 doctype-system = 10 "http://www.w3.org/MarkUp/html-spec/html-spec_toc.html"11 doctype-public = "-//W3C//DTD HTML 2.0//EN"/>12 13 <xsl:include href = "/XSLT/cHTML/error.xsl"/>14 15 <xsl:template match = "product">16 <html>17 18 <head>19 <title>20 <xsl:value-of select = "title"/> -- Description21 </title>22 </head>23 24 <body>25 <div class = "header">26 <xsl:value-of select = "title"/>27 </div>28 29 <div class = "author">30 by <xsl:value-of select = "author"/>31 </div>32


document to create appropriate cHTML representation


Outline


33 34 <div class = "productDetails">35 <table>36 <tr>37 <td style = "text-align: center;">38 <img class = "bookCover" 39 src = "images/{image}"/> 40 </td>41 42 <td>43 <p style = "text-align: right;">44 Price: <xsl:value-of select = "price"/>45 </p>46 47 <p style = "text-align: right;">48 ISBN: <xsl:value-of select = "ISBN"/>49 </p>50 51 <p style = "text-align: right;">52 Pages: <xsl:value-of select = "pages"/>53 </p> 54 55 <p style = "text-align: right;">56 Publisher: 57 <xsl:value-of select = "publisher"/>58 </p>59 60 61 <form method="post" action="AddToCart">62 <p style = "text-align: center;">63 <input type = "submit" 64 value = "Add to cart"/>65 </p>66


Outline


67 <input type = "hidden" name = "ISBN" 68 value = "{ISBN}"/>69 </form>70 </td>71 </tr>72 </table>73 </div>74 </body>75 76 </html>77 </xsl:template>78 </xsl:stylesheet>


Outline

Fig. 17.9 cHTML document generated by XSLT in Get-ProductServlet (part 1).

1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 2.0//EN" 2 "http://www.w3.org/MarkUp/html-spec/html-spec_toc.html">3 <html>4 <head>5 <META http-equiv="Content-Type" 6 content="text/html; charset=UTF-8">7 <title>XML How to Program -- Description</title>8 </head>9 <body>10 <div class="header">XML How to Program</div>11 <div class="author">12 by Deitel, Deitel, Nieto, Lin & Sadhu</div>13 <div class="productDetails">14 <table>15 <tr>16 <td style="text-align: center;">17 <img src="images/xmlhtp1.jpg" class="bookCover">18 </td>19 <td>20 <p style="text-align: right;">Price: $69.95</p>21 22 <p style="text-align: right;">ISBN: 0130284173</p>23 24 <p style="text-align: right;">Pages: 1100</p>25 26 <p style="text-align: right;">27 Publisher: Prentice Hall</p>28 29 <form action="AddToCart" method="post">30 <p style="text-align: center;">31 <input value="Add to cart" type="submit">32 </p>33 <input value="0130284173" name="ISBN" 34 type="hidden">35 </form>


Outline

Fig. 17.9 cHTML document generated by XSLT in Get-ProductServlet (part 2).

36 </td>37 </tr>38 </table>39 </div>40 </body>41 </html>

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Chapter 17: Enterprise Java Case Study: Architectural Overview