Home > Articles > Programming > Java

📄 Contents

  1. What Is Facelets?
  2. Developing a Simple Facelets Application
  3. Templating
  4. Composite Components
  5. Resources
  • Print
  • + Share This
This chapter is from the book

Developing a Simple Facelets Application

This section describes the general steps involved in developing a JavaServer Faces application. The following tasks are usually required:

  • Developing the backing beans
  • Creating the pages using the component tags
  • Defining page navigation
  • Mapping the FacesServlet instance
  • Adding managed bean declarations

Creating a Facelets Application

The example used in this tutorial is the guessnumber application. The application presents you with a page that asks you to guess a number between 0 and 10, validates your input against a random number, and responds with another page that informs you whether you guessed the number correctly or incorrectly.

Developing a Backing Bean

In a typical JavaServer Faces application, each page of the application connects to a backing bean, a type of managed bean. The backing bean defines the methods and properties that are associated with the components.

The following managed bean class, UserNumberBean.java, generates a random number from 0 to 10:

package guessNumber;

import java.util.Random;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

@ManagedBean
@SessionScoped
public class UserNumberBean {

    Integer randomInt = null;
    Integer userNumber = null;
    String response = null;
    private long maximum=10;
    private long minimum=0;

    public UserNumberBean() {
        Random randomGR = new Random();
        randomInt = new Integer(randomGR.nextInt(10));
        System.out.println("Duke's number: " + randomInt);
    }
    public void setUserNumber(Integer user_number) {
        userNumber = user_number;
    }

    public Integer getUserNumber() {
        return userNumber;
    }

    public String getResponse() {
        if ((userNumber != null) && (userNumber.compareTo(randomInt) == 0)) {
            return  "Yay! You got it!";
        } else {
            return  "Sorry,  "  + userNumber +  "  is incorrect.";
        }
    }

    public long getMaximum() {
        return (this.maximum);
    }

    public void setMaximum(long maximum) {
        this.maximum = maximum;
    }

    public long getMinimum() {
        return (this.minimum);
    }

    public void setMinimum(long minimum) {
        this.minimum = minimum;
    }
}

Note the use of the @ManagedBean annotation, which registers the backing bean as a resource with JavaServer Faces implementation. The @SessionScoped annotation registers the bean scope as session.

Creating Facelets Views

Creating a page or view is the responsibility of a page author. This task involves adding components on the pages, wiring the components to backing bean values and properties, and registering converters, validators, or listeners onto the components.

For the example application, XHTML web pages serve as the front end. The first page of the example application is a page called greeting.xhtml. A closer look at various sections of this web page provides more information.

The first section of the web page declares the content type for the page, which is XHTML:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

The next section declares the XML namespace for the tag libraries that are used in the web page:

<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core">

The next section uses various tags to insert components into the web page:

h:head>
        <title>Guess Number Facelets Application</title>
    </h:head>
    <h:body>
        <h:form>
            <h:graphicImage value="#{resource['images:wave.med.gif']}"/>
            <h2>
                Hi, my name is Duke. I am thinking of a number from
                #{userNumberBean.minimum} to #{userNumberBean.maximum}.
                Can you guess it?
                <p></p>
                <h:inputText
                    id="userNo"
                    value="#{userNumberBean.userNumber}">
                    <f:validateLongRange
                        minimum="#{userNumberBean.minimum}"
                        maximum="#{userNumberBean.maximum}"/>
                </h:inputText>

                <h:commandButton id="submit" value="Submit"
                                 action="response.xhtml"/>
                <h:message showSummary="true" showDetail="false"
                           style="color: red;
                           font-family: 'New Century Schoolbook', serif;
                           font-style: oblique;
                           text-decoration: overline"
                           id="errors1"
                           for="userNo"/>
        </h2>
    </h:form>
</h:body>

Note the use of the following tags:

  • Facelets HTML tags (those beginning with h:) to add components
  • The Facelets core tag f:validateLongRange to validate the user input

An inputText component accepts user input and sets the value of the backing bean property userNumber through the EL expression #{userNumberBean.userNumber}. The input value is validated for value range by the JavaServer Faces standard validator f:validateLongRange.

The image file, wave.med.gif, is added to the page as a resource. For more details about the resources facility, see "Resources" on page 96.

A commandButton component with the ID submit starts validation of the input data when a user clicks the button. Using implicit navigation, the component redirects the client to another page, response.xhtml, which shows the response to your input.

You can now create the second page, response.xhtml, with the following content:

<!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>Guess Number Facelets Application</title>
    </h:head>
    <h:body>
        <h:form>
            <h:graphicImage value="#{resource['images:wave.med.gif']}"/>
            <h2>
                <h:outputText id="result" value="#{userNumberBean.response}"/>
            </h2>
            <h:commandButton id="back" value="Back" action="greeting.xhtml"/>
        </h:form>
    </h:body>
</html>

Configuring the Application

Configuring a JavaServer Faces application involves mapping the Faces Servlet in the web deployment descriptor file, such as a web.xml file, and possibly adding managed bean declarations, navigation rules, and resource bundle declarations to the application configuration resource file, faces-config.xml.

If you are using NetBeans IDE, a web deployment descriptor file is automatically created for you. In such an IDE-created web.xml file, change the default greeting page, which is index.xhtml,to greeting.xhtml. Here is an example web.xml file, showing this change in bold.

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
  http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <context-param>
        <param-name>javax.faces.PROJECT_STAGE</param-name>
        <param-value>Development</param-value>
    </context-param>
    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>faces/greeting.xhtml</welcome-file>
    </welcome-file-list>
</web-app>

Note the use of the context parameter PROJECT_STAGE. This parameter identifies the status of a JavaServer Faces application in the software lifecycle.

The stage of an application can affect the behavior of the application. For example, if the project stage is defined as Development, debugging information is automatically generated for the user. If not defined by the user, the default project stage is Production.

Building, Packaging, Deploying, and Running the guessnumber Facelets Example

You can use either NetBeans IDE or Ant to build, package, deploy, and run the guessnumber example. The source code for this example is available in the tut-install /examples/web/guessnumber directory.

To Build, Package, and Deploy the guessnumber Example Using NetBeans IDE

  1. In NetBeans IDE, select File u2192.jpg Open Project.
  2. In the Open Project dialog, navigate to:tut-install/examples/web/
  3. Select the guessnumber folder.
  4. Select the Open as Main Project check box.
  5. Click Open Project.
  6. In the Projects tab, right-click the guessnumber project and select Deploy.

    This option builds and deploys the example application to your GlassFish Server instance.

To Build, Package, and Deploy the guessnumber Example Using Ant

  1. In a terminal window, go to: tut-install /examples/web/guessnumber/
  2. Type the following command:

    ant

    This command calls the default target, which builds and packages the application into a WAR file, guessnumber.war, that is located in the dist directory.

  3. Make sure that the GlassFish Server is started.
  4. To deploy the application, type the following command:
    ant deploy

To Run the guessnumber Example

  1. Open a web browser.
  2. Type the following URL in your web browser:

    http://localhost:8080/guessnumber

    The web page shown in Figure 5–1 appears.

    Figure 5-1

    Figure 5–1 Running the Application

  3. In the text field, type a number from 0 to 10 and click Submit.

    Another page appears, reporting whether your guess is correct or incorrect.

  4. If you guessed incorrectly, click the Back button to return to the main page.

    You can continue to guess until you get the correct answer.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020