SeamFramework.orgCommunity Documentation
The Web Beans is being developed at the Seam project. You can download the latest developer release of Web Beans from the the downloads page.
Web Beans comes with a two deployable example applications: webbeans-numberguess
, a war example, containing only simple beans, and webbeans-translator
an ear example, containing enterprise beans. There are also two variations on the numberguess example, the tomcat example (suitable for deployment to Tomcat) and the jsf2 example, which you can use if you are running JSF2. To run the examples you'll need the following:
the latest release of Web Beans,
JBoss AS 5.0.1.GA, or
Apache Tomcat 6.0.x, and
Ant 1.7.0。
You'll need to download JBoss AS 5.0.1.GA from jboss.org, and unzip it. For example:
$ cd /Applications $ unzip ~/jboss-5.0.1.GA.zip
Next, download Web Beans from seamframework.org, and unzip it. For example
$ cd ~/ $ unzip ~/webbeans-$VERSION.zip
接下來,我們需要讓 Web Bean 知道 JBoss 的位置在哪裡。請編輯 jboss-as/build.properties
然後設置 jboss.home
內容。例如:
jboss.home=/Applications/jboss-5.0.1.GA
To install Web Beans, you'll need Ant 1.7.0 installed, and the ANT_HOME
environment variable set. For example:
JBoss 5.1.0 comes with Web Beans built in, so there is no need to update the server.
$ unzip apache-ant-1.7.0.zip $ export ANT_HOME=~/apache-ant-1.7.0
Then, you can install the update. The update script will use Maven to download Web Beans automatically.
$ cd webbeans-$VERSION/jboss-as $ ant update
現在,您已準備好建置您的第一個範例!
The build scripts for the examples offer a number of targets for JBoss AS, these are:
ant restart
- 以分解的格式來建置範例
ant explode
- 在不重新建置的情況下更新一個已分解的範例
ant deploy
- 以 jar 格式來建置範例
ant undeploy
- 將範例由伺服器中移除
ant clean
- 清除範例
若要建置 numberguess 範例:
$ cd examples/numberguess ant deploy
Start JBoss AS:
$ /Application/jboss-5.0.0.GA/bin/run.sh
If you use Windows, use the run.bat
script.
請等待應用程式的建置,然後在 http://localhost:8080/webbeans-numberguess 花上幾個小時!
Web Beans includes a second simple example that will translate your text into Latin. The numberguess example is a war example, and uses only simple beans; the translator example is an ear example, and includes enterprise beans, packaged in an EJB module. To try it out:
$ cd examples/translator ant deploy
請等待應用程式的建置並進入 http://localhost:8080/webbeans-translator!
You'll need to download Tomcat 6.0.18 or later from tomcat.apache.org, and unzip it. For example:
$ cd /Applications $ unzip ~/apache-tomcat-6.0.18.zip
Next, download Web Beans from seamframework.org, and unzip it. For example
$ cd ~/ $ unzip ~/webbeans-$VERSION.zip
Next, we need to tell Web Beans where Tomcat is located. Edit jboss-as/build.properties
and set the tomcat.home
property. For example:
tomcat.home=/Applications/apache-tomcat-6.0.18
The build scripts for the examples offer a number of targets for Tomcat, these are:
ant tomcat.restart
- deploy the example in exploded format
ant tomcat.explode
- update an exploded example, without restarting the deployment
ant tomcat.deploy
- deploy the example in compressed jar format
ant tomcat.undeploy
- remove the example from the server
ant tomcat.clean
- clean the example
To deploy the numberguess example for tomcat:
$ cd examples/tomcat ant tomcat.deploy
Start Tomcat:
$ /Applications/apache-tomcat-6.0.18/bin/startup.sh
If you use Windows, use the startup.bat
script.
請等待應用程式的建置,然後在 http://localhost:8080/webbeans-numberguess 花上幾個小時!
在 numberguess 應用程式中,您將會有 10 次機會來猜一個介於 1 至 100 之間的號碼。每當猜過一遍,系統便會告知您您所輸入的數字是否太大或太小。
numberguess 範例包含了 Web Bean 的一個數字、配置檔案,以及 Facelet JSF 頁面,並且封裝為 war。讓我們先從配置檔案開始。
此範例的所有配置檔案都位於 WEB-INF/
中,並且它又儲存在來源樹中的 WebContent
裡。首先,我們有個可使用來指定 JSF 來使用 Facelet 的 faces-config.xml
:
<?xml version='1.0' encoding='UTF-8'?>
<faces-config version="1.2"
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-facesconfig_1_2.xsd">
<application>
<view-handler
>com.sun.facelets.FaceletViewHandler</view-handler>
</application>
</faces-config
>
有個空的 web-beans.xml
檔案,它會將此應用程式標記為一個 Web Bean 應用程式。
最後為 web.xml
:
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" 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_2_5.xsd"> <display-name>Web Beans Numbergues example</display-name> <!-- JSF --> <servlet><servlet-name>Faces Servlet</servlet-name> <servlet-class>javax.faces.webapp.FacesServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-ma
pping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>*.jsf</url-pattern> </servlet-mapping> <context-pa
ram> <param-name>javax.faces.DEFAULT_SUFFIX</param-name> <param-value>.xhtml</param-value> </context-param> <session-co
nfig> <session-timeout>10</session-timeout> </session-config> </web-app>
![]() | Enable and load the JSF servlet |
![]() | Configure requests to |
![]() | Tell JSF that we will be giving our source files (facelets) an extension of |
![]() | Configure a session timeout of 10 minutes |
Whilst this demo is a JSF demo, you can use Web Beans with any Servlet based web framework.
Let's take a look at the Facelet view:
<!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:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:s="http://jboss.com/products/seam/taglib"> <ui:composition template="template.xhtml"> <ui:define name="content"> <h1>Guess a number...</h1> <h:form id="NumberGuessMain"> <div
style="color: red"> <h:messages id="messages" globalOnly="false"/> <h:outputText id="Higher" value="Higher!" rendered="#{game.number gt game.guess and game.guess ne 0}"/> <h:outputText id="Lower" value="Lower!" rendered="#{game.number lt game.guess and game.guess ne 0}"/> </div> <div> I
'm thinking of a number between #{game.smallest} and #{game.biggest}. You have #{game.remainingGuesses} guesses. </div> <div> Your guess: <
h:inputText id="inputGuess" value="#{game.guess}" required="true" size="3" disabled="#{game.number eq game.guess}">
<f:validateLongRange maximum="#{game.biggest}" minimum="#{game.smallest}"/> </h:inputText> <h
:commandButton id="GuessButton" value="Guess" action="#{game.check}" disabled="#{game.number eq game.guess}"/> </div> <div> <h:commandButton id="RestartButton" value="Reset" action="#{game.reset}" immediate="true" /> </div> </h:form> </ui:define> </ui:composition> </html>
![]() | Facelets is a templating language for JSF, here we are wrapping our page in a template which defines the header. |
![]() | There are a number of messages which can be sent to the user, "Higher!", "Lower!" and "Correct!" |
![]() | As the user guesses, the range of numbers they can guess gets smaller - this sentance changes to make sure they know what range to guess in. |
![]() | This input field is bound to a Web Bean, using the value expression. |
![]() | A range validator is used to make sure the user doesn't accidentally input a number outside of the range in which they can guess - if the validator wasn't here, the user might use up a guess on an out of range number. |
![]() | And, of course, there must be a way for the user to send their guess to the server. Here we bind to an action method on the Web Bean. |
範例存有 4 個類別,前兩個為綁定類型。首先,有個使用來注入亂數號碼的 @Random
綁定類型:
@Target( { TYPE, METHOD, PARAMETER, FIELD })
@Retention(RUNTIME)
@Documented
@BindingType
public @interface Random {}
還有個用來注入可注入之最大號碼的 @MaxNumber
綁定類型:
@Target( { TYPE, METHOD, PARAMETER, FIELD })
@Retention(RUNTIME)
@Documented
@BindingType
public @interface MaxNumber {}
Generator
類別負責透過產生器的方式來建立亂數號碼。它也會透過一個產生器的方式來顯示最大的可能號碼:
@ApplicationScoped
public class Generator {
private java.util.Random random = new java.util.Random( System.currentTimeMillis() );
private int maxNumber = 100;
java.util.Random getRandom()
{
return random;
}
@Produces @Random int next() {
return getRandom().nextInt(maxNumber);
}
@Produces @MaxNumber int getMaxNumber()
{
return maxNumber;
}
}
您將會注意到 Generator
是屬於應用程式導向的;因此,我們不會每次都一定能得到不同的亂數號碼。
應用程式中最後的 Web Bean 為 session 導向的 Game
。
您將會注意到我們使用了 @Named
標記,如此一來我們便可在 JSF 頁面中的 EL 上使用這個 bean。最後,我們使用了 constructor injection 來利用亂數號碼來初始化了這個遊戲。當然,當玩家贏時我們將需要告知玩家,並藉由一個 FacesMessage
來給予回應。
package org.jboss.webbeans.examples.numberguess;
import javax.annotation.PostConstruct;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.webbeans.AnnotationLiteral;
import javax.webbeans.Current;
import javax.webbeans.Initializer;
import javax.webbeans.Named;
import javax.webbeans.SessionScoped;
import javax.webbeans.manager.Manager;
@Named
@SessionScoped
public class Game
{
private int number;
private int guess;
private int smallest;
private int biggest;
private int remainingGuesses;
@Current Manager manager;
public Game()
{
}
@Initializer
Game(@MaxNumber int maxNumber)
{
this.biggest = maxNumber;
}
public int getNumber()
{
return number;
}
public int getGuess()
{
return guess;
}
public void setGuess(int guess)
{
this.guess = guess;
}
public int getSmallest()
{
return smallest;
}
public int getBiggest()
{
return biggest;
}
public int getRemainingGuesses()
{
return remainingGuesses;
}
public String check()
{
if (guess
>number)
{
biggest = guess - 1;
}
if (guess<number)
{
smallest = guess + 1;
}
if (guess == number)
{
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Correct!"));
}
remainingGuesses--;
return null;
}
@PostConstruct
public void reset()
{
this.smallest = 0;
this.guess = 0;
this.remainingGuesses = 10;
this.number = manager.getInstanceByType(Integer.class, new AnnotationLiteral<Random
>(){});
}
}
The numberguess for Tomcat differs in a couple of ways. Firstly, Web Beans should be deployed as a Web Application library in WEB-INF/lib
. For your convenience we provide a single jar suitable for running Web Beans in any servlet container webbeans-servlet.jar
.
Of course, you must also include JSF and EL, as well common annotations (jsr250-api.jar
) which a JEE server includes by default.
Secondly, we need to explicitly specify the servlet listener (used to boot Web Beans, and control it's interaction with requests) in web.xml
:
<listener> <listener-class>org.jboss.webbeans.environment.servlet.Listener</listener-class> </listener>
Whilst JSR-299 specifies integration with Java ServerFaces, Web Beans allows you to inject into Wicket components, and also allows you to use a conversation context with Wicket. In this section, we'll walk you through the Wicket version of the numberguess example.
You may want to review the Wicket documentation at http://wicket.apache.org/.
Like the previous example, the Wicket WebBeans examples make use of the webbeans-servlet
module. The use of the Jetty servlet container is common in the Wicket community, and is chosen here as the runtime container in order to facilitate comparison between the standard Wicket examples and these examples, and also to show how the webbeans-servlet integration is not dependent upon Tomcat as the servlet container.
These examples make use of the Eclipse IDE; instructions are also given to deploy the application from the command line.
To generate an Eclipse project from the example:
cd examples/wicket/numberguess mvn -Pjetty eclipse:eclipse
Then, from eclipse, choose File -> Import -> General -> Existing Projects into Workspace, select the root directory of the numberguess example, and click finish. Note that if you do not intend to run the example with jetty from within eclipse, omit the "-Pjetty." This will create a project in your workspace called webbeans-wicket-numberguess
This project follows the wicket-quickstart
approach of creating an instance of Jetty in the Start
class. So running the example is as simple as right-clicking on that Start class in src/test/java
in the Package Explorer and choosing Run as Java Application. You should see console output related to Jetty starting up; then visit able http://localhost:8080
to view the app. To debug choose Debug as Java Application.
This example can also be deployed from the command line in a (similar to the other examples). Assuming you have set up the build.properties
file in the examples
directory to specify the location of JBoss AS or Tomcat, as previously described, you can run ant deploy
from the examples/wicket/numberguess
directory, and access the application at http://localhost:8080/webbeans-numberguess-wicket
.
JSF uses Unified EL expressions to bind view layer components in JSP or Facelet views to beans, Wicket defines it's components in Java. The markup is plain html with a one-to-one mapping between html elements and the view components. All view logic, including binding of components to models and controlling the response of view actions, is handled in Java. The integration of Web Beans with Wicket takes advantage of the same binding annotations used in your business layer to provide injection into your WebPage subclass (or into other custom wicket component subclasses).
The code in the wicket numberguess example is very similar to the JSF-based numberguess example. The business layer is identical!
Differences are:
Each wicket application must have a WebApplication
subclass, In our case, our application class is SampleApplication
:
public class SampleApplication extends WebBeansApplication { @Override public Class getHomePage() { return HomePage.class; } }
This class specifies which page wicket should treat as our home page, in our case, HomePage.class
In HomePage
we see typical wicket code to set up page elements. The bit that is interesting is the injection of the Game
bean:
@Current Game game;
The Game
bean is can then be used, for example, by the code for submitting a guess:
final Component guessButton = new AjaxButton("GuessButton") { protected void onSubmit(AjaxRequestTarget target, Form form) { if (game.check()) {
All injections may be serialized; actual storage of the bean is managed by JSR-299. Note that Wicket components, like the HomePage and it subcomponents, are not JSR-299 beans.
Wicket components allow injection, but they cannot use interceptors, decorators and lifecycle callbacks such as @PostConstruct
or @Initializer
methods.
The example uses AJAX for processing of button events, and dynamically hides buttons that are no longer relevant, for example when the user has won the game.
In order to activate wicket for this webapp, the Wicket filter is added to web.xml, and our application class is specified:
<filter> <filter-name>wicket.numberguess-example</filter-name> <filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class> <init-param> <param-name>applicationClassName</param-name> <param-value>org.jboss.webbeans.examples.wicket.SampleApplication</param-value> </init-param> </filter> <filter-mapping> <filter-name>wicket.numberguess-example</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <listener-class>org.jboss.webbeans.environment.servlet.Listener</listener-class> </listener>
Note that the servlet listener is also added, as in the Tomcat example, in order to boostrap Web Beans when Jetty starts, and to hook Web Beans into the Jetty servlet request and session lifecycles.
This example can be found in the examples/se/numberguess
folder of the Web Beans distribution.
To run this example:
Open a command line/terminal window in the examples/se/numberguess
directory
Ensure that Maven 2 is installed and in your PATH
Ensure that the JAVA_HOME
environment variable is pointing to your JDK installation
execute the following command
mvn -Drun
There is an empty beans.xml
file in the root package (src/main/resources/beans.xml
), which marks this application as a Web Beans application.
The game's main logic is located in Game.java
. Here is the code for that class, highlighting the changes made from the web application version:
@ApplicationScoped
public class Game implements Serializable
{
private int number;
private int guess;
private int smallest;
@MaxNumber
private int maxNumber;
private int biggest;
private int remainingGuesses;
private boolean validNumberRange = true;
@Current Generator rndGenerator;
...
public boolean isValidNumberRange()
{
return validNumberRange;
}
public boolean isGameWon(){
return guess == number;
}
public boolean isGameLost()
{
return guess != number && remainingGuesses <= 0;
}
public boolean check()
{
boolean result = false;if ( checkNewNumberRangeIsValid() )
{
if ( guess > number )
{
biggest = guess - 1;
}
if ( guess < number )
{
smallest = guess + 1;
}
if ( guess == number )
{
result = true;
}
remainingGuesses--;
}
return result;
}
private boolean checkNewNumberRangeIsValid()
{
return validNumberRange = ( ( guess >= smallest ) && ( guess <= biggest ) );
}
@PostConstructpublic void reset()
{
this.smallest = 0;
...
this.number = rndGenerator.next();
}
}
![]() | The bean is application scoped instead of session scoped, since an instance of the application represents a single 'session'. |
![]() | The bean is not named, since it doesn't need to be accessed via EL |
![]() | There is no JSF
This allows the Swing UI to query the state of the game, which it does indirectly via a class called |
![]() | Validation of user input is performed during the |
![]() | The |
The MessageGenerator
class depends on the current instance of Game
, and queries its state in order to determine the appropriate messages to provide as the prompt for the user's next guess and the response to the previous guess. The code for MessageGenerator
is as follows:
public class MessageGenerator
{@Current Game game;
public String getChallengeMessage()
{
StringBuilder challengeMsg = new StringBuilder( "I'm thinking of a number between " );
challengeMsg.append( game.getSmallest() );
challengeMsg.append( " and " );
challengeMsg.append( game.getBiggest() );
challengeMsg.append( ". Can you guess what it is?" );
return challengeMsg.toString();
}public String getResultMessage()
{
if ( game.isGameWon() )
{
return "You guess it! The number was " + game.getNumber();
} else if ( game.isGameLost() )
{
return "You are fail! The number was " + game.getNumber();
} else if ( ! game.isValidNumberRange() )
{
return "Invalid number range!";
} else if ( game.getRemainingGuesses() == Game.MAX_NUM_GUESSES )
{
return "What is your first guess?";
} else
{
String direction = null;
if ( game.getGuess() < game.getNumber() )
{
direction = "Higher";
} else
{
direction = "Lower";
}
return direction + "! You have " + game.getRemainingGuesses() + " guesses left.";
}
}
}
![]() | The instance of |
![]() | The |
![]() | And again to determine whether to congratulate, console or encourage the user to continue. |
Finally we come to the NumberGuessFrame
class which provides the Swing front end to our guessing game.
public class NumberGuessFrame extends javax.swing.JFrame
{private @Current Game game;
private @Current MessageGenerator msgGenerator;
public void start( @Observes @Deployed Manager manager )
{
java.awt.EventQueue.invokeLater( new Runnable()
{
public void run()
{
initComponents();
setVisible( true );
}
} );
}private void initComponents() {
buttonPanel = new javax.swing.JPanel();
mainMsgPanel = new javax.swing.JPanel();
mainLabel = new javax.swing.JLabel();
messageLabel = new javax.swing.JLabel();
guessText = new javax.swing.JTextField();
...
mainLabel.setText(msgGenerator.getChallengeMessage());
mainMsgPanel.add(mainLabel);
messageLabel.setText(msgGenerator.getResultMessage());
mainMsgPanel.add(messageLabel);
...
}private void guessButtonActionPerformed( java.awt.event.ActionEvent evt )
{
int guess = Integer.parseInt(guessText.getText());
game.setGuess( guess );
game.check();
refreshUI();
}private void replayBtnActionPerformed( java.awt.event.ActionEvent evt )
{
game.reset();
refreshUI();
}private void refreshUI()
{
mainLabel.setText( msgGenerator.getChallengeMessage() );
messageLabel.setText( msgGenerator.getResultMessage() );
guessText.setText( "" );
guessesLeftBar.setValue( game.getRemainingGuesses() );
guessText.requestFocus();
}
// swing components
private javax.swing.JPanel borderPanel;
...
private javax.swing.JButton replayBtn;
}
![]() | The injected instance of the game (logic and state). |
![]() | The injected message generator for UI messages. |
![]() | This application is started in the usual Web Beans SE way, by observing the |
![]() | This method initialises all of the Swing components. Note the use of the |
![]() |
|
![]() | |
![]() | |
轉譯器範例能接受您所輸入的任何句子,然後將它們翻譯成拉丁文。
轉換器範例被建置為一個 ear 並包含著 EJB。正因如此,它的結構比 numberguess 範例要複雜得多。
EJB 3.1 和 Jave EE 6 能讓您將 EJB 封裝為 war,並使得該結構變得更為簡樸!
首先,讓我們先來看一下 ear 聚合器,它位於 webbeans-translator-ear
模組中。Maven 會自動地為我們產生 application.xml
:
<plugin>
<groupId
>org.apache.maven.plugins</groupId>
<artifactId
>maven-ear-plugin</artifactId>
<configuration>
<modules>
<webModule>
<groupId
>org.jboss.webbeans.examples.translator</groupId>
<artifactId
>webbeans-translator-war</artifactId>
<contextRoot
>/webbeans-translator</contextRoot>
</webModule>
</modules>
</configuration>
</plugin
>
在此我們將設置 context 路徑,它能提供給我們一個網址(http://localhost:8080/webbeans-translator)。
若您不使用 Maven 來產生這些檔案,那麼您將需要 META-INF/application.xml
:
<?xml version="1.0" encoding="UTF-8"?>
<application 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/application_5.xsd"
version="5">
<display-name
>webbeans-translator-ear</display-name>
<description
>Ear Example for the reference implementation of JSR 299: Web Beans</description>
<module>
<web>
<web-uri
>webbeans-translator.war</web-uri>
<context-root
>/webbeans-translator</context-root>
</web>
</module>
<module>
<ejb
>webbeans-translator.jar</ejb>
</module>
</application
>
Next, lets look at the war. Just as in the numberguess example, we have a faces-config.xml
(to enable Facelets) and a web.xml
(to enable JSF) in WebContent/WEB-INF
.
還有更有趣的就是使用來轉換文字的 facelet。就和 numberguess 範例中一樣,我們有個圍繞著 form 的頁面格式(在此將省略不提):
<h:form id="NumberGuessMain">
<table>
<tr align="center" style="font-weight: bold" >
<td>
Your text
</td>
<td>
Translation
</td>
</tr>
<tr>
<td>
<h:inputTextarea id="text" value="#{translator.text}" required="true" rows="5" cols="80" />
</td>
<td>
<h:outputText value="#{translator.translatedText}" />
</td>
</tr>
</table>
<div>
<h:commandButton id="button" value="Translate" action="#{translator.translate}"/>
</div>
</h:form
>
用戶可在左手邊的文字區域中輸入一些文字,然後點選轉譯按鈕並於右手邊的區域中查看結果。
最後,讓我們來看一下 ejb 模組 webbeans-translator-ejb
。在 src/main/resources/META-INF
中只有一個用來將 archive 標記為包含著 Web Bean 的空 web-beans.xml
。
我們將最有趣的部份保留到了最後,那就是程式碼!該專案含有兩個基本的 bean,SentenceParser
和 TextTranslator
,以及兩個企業級的 bean,TranslatorControllerBean
和 SentenceTranslator
。到了現在您應該已經很熟悉 Web Bean 長得如何了,因此我們在此將只著重於其它較有趣的部份。
SentenceParser
和 TextTranslator
兩者皆為相依性的 bean,並且 TextTranslator
使用了 constructor 初始化:
public class TextTranslator {
private SentenceParser sentenceParser;
private Translator sentenceTranslator;
@Initializer
TextTranslator(SentenceParser sentenceParser, Translator sentenceTranslator)
{
this.sentenceParser = sentenceParser;
this.sentenceTranslator = sentenceTranslator;
TextTranslator
是個無狀態的 bean(以及一個本地的商業介面)- 當然,我們無法開發一個完整的轉譯器。
最後,有個 UI 導向的控制器,它會藉由用戶收集文字然後將它發送給轉譯器。這是個請求導向、被命名,而有狀態的 session bean,並且會注入轉譯器。
@Stateful
@RequestScoped
@Named("translator")
public class TranslatorControllerBean implements TranslatorController
{
@Current TextTranslator translator;
這個 bean 針對於頁面上所有欄位都有 getter 與 setter。
因為這是個 stateful(有狀態)的 session bean,因此我們必須要有個 remove method:
@Remove
public void remove()
{
}
當 bean 被毀掉後,Web Bean 管理員會為您調用 remove 這個 method;在此情況下為請求結束之後。
That concludes our short tour of the Web Beans examples. For more on Web Beans , or to help out, please visit http://www.seamframework.org/WebBeans/Development.
我們在所有層面都需要協助 - 錯誤修正、編寫新功能、編寫範例,以及翻譯此參照指南。