Why is it defined this way in web.xml in JSF? - cdi

In this little project, there is only one class RichBean.java, and a JSF file index.html, to demonstrate the use of CDI in JSF. My question is regarding the "
<welcome-file>faces/index.xhtml</welcome-file>"
defined in web.xml. Why is it "faces/"?
There is no any mentioning of "faces/" directory or configuration. I thought "faces" is just a name that can be anything, but it isn't the case. I tried changing it to something else, i.e. "faceg", it then doesn't work.
RichBean.java
#Named
#SessionScoped
public class RichBean implements Serializable {
private String name;
#PostConstruct
public void postContruct() {
name = "John";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
index.xhtml
....
<body>
<ui:composition template="/templates/template.xhtml">
<ui:define name="title">Hello world JSF</ui:define>
<ui:define name="body">
<fieldset style="width:500px">
<legend>Helloworld using JSF and RichFaces</legend>
<p>
This example demonstrates adding ajax processing and updating to a standard JSF component.
</p>
<rich:panel header="Ajax enabled inputText">
<h:form id="helloWorldJsf">
<h:outputLabel value="Name:" for="nameInput"/>
<h:inputText id="nameInput" value="#{richBean.name}">
<a4j:ajax event="keyup" render="output"/>
</h:inputText>
<h:panelGroup id="output">
<h:outputText value="Hello #{richBean.name}!"
rendered="#{not empty richBean.name}"/>
</h:panelGroup>
</h:form>
</rich:panel>
</fieldset>
</ui:define>
</ui:composition>
</body>
</html>
beans.xml
<beans 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/beans_1_0.xsd">
</beans>
web.xml.
How is "faces/" configured? I have no idea of how and why it's connected to anything else in the proejct.
I am learning this demo. Please help understand this. Thanks a lot.
<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">
<!-- add a welcome-file-list entry to allow JSF pages to be used as welcome files -->
<welcome-file-list>
<welcome-file>faces/index.xhtml</welcome-file>
</welcome-file-list>
</web-app>

The Servlet class FacesServlet starts the JSF request processing
life cycle and must be defined in the web.xml. The servlet mapping
tag defines the for which URL the FacesServlet should be executed.
The pattern /faces/* is commonly used by the JSF specification but
any other prefix or extension is possible. The example uses as
web-app attribute version=“2.5” this means we are using
servlet-api version 2.5. If you use tomcat 6 we need minimum
servlet-api in version 2.5. Compared with jsf 1.2 nothing changed in
this example.
Below you can see the web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app 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 web-app_2_5.xsd"
version="2.5">
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
<display-name>HelloWorld with JSF RI 2 (Beta 2)</display-name>
<servlet>
<display-name>FacesServlet</display-name>
<servlet-name>FacesServlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>FacesServlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
</servlet-mapping>
</web-app>
You can change /faces/ to /facesg/ as per your requirement and it will work for you.
I hope it will resolve your query !!

Related

JSF bean action method return string test

I tried to understand from this question the difference between returning null and "" in JSF action, but couldn't experience in real.
Below is the quote form the OP
From what I understand, when a JSF action returns "" (empty String)
the user stays on the current page but the view is refreshed. However,
when the action returns null the user still stays on the current page
but the old view is reused
I am in a confusion of understanding the difference between returning "", null and "viewid?faces-redirect=true" from a JSF Backing bean. I tried to understand the difference with a small example, but I couldn't experience the actual difference. Below are the code snippets of my example.
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name>Jsf Questions</display-name>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<context-param>
<param-name>javax.faces.DEFAULT_SUFFIX</param-name>
<param-value>.jspx</param-value>
</context-param>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/jsfintroapp/*</url-pattern>
</servlet-mapping>
</web-app>
faces-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<faces-config version="1.2" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xi="http://www.w3.org/2001/XInclude"
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">
<managed-bean>
<managed-bean-name>userLogin</managed-bean-name>
<managed-bean-class>com.srk.beans.UserLogin</managed-bean-class>
<managed-bean-scope>request</managed-bean-scope>
</managed-bean>
<navigation-rule>
<description>Contains list of all navigation rules here</description>
<from-view-id>/*</from-view-id>
<navigation-case>
<display-name>WELCOME</display-name>
<from-outcome>welcome</from-outcome>
<to-view-id>/geek_examples/authorized_user.jspx</to-view-id>
</navigation-case>
</faces-config>
My managed bean is a request scoped bean, as declared above.
UserLogin.java (Backing bean) code snippet
public String saveData() {
//String returnString = "";//Case 1 : works - user stays on the same page
//String returnString = null;//Case 2: works - user stays on the same page
// Case 3:
String viewId = FacesContext.getCurrentInstance().getViewRoot().getViewId();
LOG.debug("view id = "+ viewId);
String returnString = "?faces-redirect=true";//viewId+
LOG.debug("return string = "+ returnString);
LOG.debug("Username = "+ getName() + " password = "+ getPassword());
return returnString;
}
login.jspx
<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">
<f:view>
<head>
<title>JSF Question</title>
</head>
<body>
<h:form>
<h3>User Name and Password</h3>
<table>
<tr>
<td><h:outputLabel value="Name"/></td>
<td><h:inputText value="#{userLogin.name}"/></td>
</tr>
<tr>
<td><h:outputLabel value="Password"/></td>
<td><h:inputText value="#{userLogin.password}"/></td>
</tr>
<tr>
<td><h:commandButton value="Sign In" action="#{userLogin.saveData}"/></td>
</tr>
</table>
</h:form>
</body>
</f:view>
</html>
Libraries used in this example
I tried to access the login.jspx page, entered values in the fields of form and clicked on Sign In. I can always see the same page, no matter what I return there in my saveData() method which is not showing any difference in behavior, Can somebody throw some light with respect to this concept?
As answered in that answer, returning null or void will reuse the same JSF view, including all view scoped beans attached to it.
JSF 1.2, however, has no concept of a "view scoped bean". This was introduced in JSF 2.0. Moreover, you've a request scoped bean. It'll always be recreated on every request, regardless of how you navigate. So it's not really noticeable by looking at how the bean behaves. It's only noticeable if you manually mimic the JSF 2.0 view scope by putting an attribute in the UIViewRoot and then checking in the constructor of the request scoped bean if it's still present.
If you have used a JSF 2.x view scoped bean, you'd have noticed that it's recreated (i.e. it's (post)constructor is invoked again) when you navigate using a non-null outcome. See also a.o. How to choose the right bean scope?
And, the ?faces-redirect=true query string is also JSF 2.x specific and not recognized by JSF 1.x. In JSF 1.x, to achieve the same effect, either add <redirect/> to the <navigation-case>, or use ExternalContext#redirect().
public void saveData() throws IOException {
// ...
ExternalContext ec = FacesContext.getCurrentInstance().getExternalContext();
String url = ec.getRequestContextPath() + "/login.jsf";
ec.redirect(url);
}
Which navigation approach to choose is elaborated in this related question: How to navigate in JSF? How to make URL reflect current page (and not previous one). Generally, in UX and SEO perspective, using POST for page-to-page navigation is bad practice. Always use GET for that or perform a redirect after POST.
In any case, when developing with JSF 1.x, you should not be looking at JSF 2.x targeted answers/resources. It'll only lead to confusion because many things are done differently (better!) in JSF 2.x. JSF 2.x exist more than 5 years already and JSF 1.x was EOL for nearly as long. It doesn't make sense to keep working on dead technology. Consider migrating.

Primefaces 5 Carousel showcase - renders images, but uses bullet points instead of a Carousel

This is what the Primefaces Carousel is looking like in Primefaces 5.0:
I created a new Eclipse(Dynamic Web Project) project in an attempt to reduce as many variables as possible.
My libraries used:
Primefaces 5.0 (I also tried many 3 and 4 versions)
Mojarra 2.2.6 (and I tried a few versions lower than this too)
running on Tomcat 7.0.52
Here is my web page code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<h:head></h:head>
<h:body>
<f:view contentType="text/html">
<h:form id="form">
<h:body>
<p:carousel circular="true" vertical="true">
<p:graphicImage name="images/csvExport.png" />
<p:graphicImage name="images/csvExport.png" />
</p:carousel>
</h:body>
</h:form>
</f:view>
</h:body>
</html>
This is my web.xml file:
<?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">
<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>
<url-pattern>*.xhtml</url-pattern>
<url-pattern>*.html</url-pattern>
<url-pattern>*.jsp</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>faces/index.xhtml</welcome-file>
</welcome-file-list>
</web-app>
Yes, I know there are other questions about the Primefaces Carousel. I read those and dozens of other articles elsewhere for most of the day.
I tried throwing .jstl libraries in there too. Adding primefaces themes added a bordering box around it, but the Carousel still wasn't right.
The web.xml file is exactly what I have in another Eclipse web project that works just fine for all the other primefaces components I have used, so I'm not thinking the web.xml file is the problem.
Any ideas on how I can get this Primefaces Carousel to render properly? the images are pulling up, but the "flesh" of the Carousel component just isn't coming through.
Edit:
The Primefaces show case for Carousel is here:
http://www.primefaces.org/showcase/ui/data/carousel.xhtml
My objective is to get the most basic Carousel to work.
Edit2(05-27-2014):
Per LarsBauer's suggestion to add a header tag, the output web page now looks a little different. It looks like a rectangle instead of a bulleted list, but still isn't quite where it needs to be. I tried adding primefaces styles in the header that I used in other Primefaces projects(copying over the files too, of course), but that didn't change anything.
Edit3(05-27-2014):
Per Templar's suggestion, I added the h:body tag. The change didn't do anything different with the output, but I would imaging the page would become problematic later on if that tag weren't there. Not sure why I forgot to add it.
Your h:form needs to be inside your h:body. Also take a look at your Javascript console to see any clientside rendering errors.
<f:view contentType="text/html">
<h:body>
<h:form id="form">
<p:carousel circular="true" vertical="true">
<p:graphicImage name="images/csvExport.png" />
<p:graphicImage name="images/csvExport.png" />
</p:carousel>
</h:form>
</h:body>
</f:view>
It sucks that it took me so many days to figure this out, but Internet Explorer 8 is the problem. Any modern browser displays everything properly. The other Primefaces components I use in other projects work fine, but not so with Carousel.
It's my company that mandates the older version be used, and I bet you'd know exactly who that is >.>

<h:button> not executing simple bean method

im trying to do a simple bean method, but it does not work, dont show the syso in the console of eclispe, and when i click the button, it change my url to http://localhost:8080/Projeto01/index.jsf?jftfdi=&jffi=%2Findex.xhtml
why dont work and why it change the url for this strange url ?
my msg.java(bean)
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
#ManagedBean
#SessionScoped
public class Msg {
public void show() {
System.out.println("Working Bean Method");
}
}
my index.xhtml
<!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"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:p="http://primefaces.org/ui"
xmlns:ui="http://java.sun.com/jsf/facelets">
<ui:composition>
<h:head></h:head>
<h:body>
<h:form>
<h:button value="Show" action="#{msg.show()}"></h:button>
</h:form>
</h:body>
</ui:composition>
</html>
and my web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name>do0</display-name>
<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>*.jsf</url-pattern>
</servlet-mapping>
</web-app>
The <h:button> is a simple page-to-page navigation button. As you can see in the tag documentation, it doesn't support the action attribute at all. You're most likely confusing the <h:button> with <h:commandButton> which in turn supports that attribute.
In order to achieve your functional requirement of invoking a JSF backing bean method on press of a button, just replace <h:button> by <h:commandButton>:
<h:commandButton value="Show" action="#{msg.show()}" />
See also:
Difference between h:button and h:commandButton
As to those jftfdi and jffi query string parameters in the target URL, this is a bug in Mojarra's implementation of the new JSF 2.2 flow scope. This is fixed in Mojarra 2.2.5. Note that this is further unrelated to your concrete problem as you shouldn't be using a <h:button> in first place.
See also:
How to disable jftfdi jffi query params in JSF

Basic JSF with Session doesn't work in glassfish

I wanted to test Session replication of session and application scoped beans of JSF 2 in a clustered environment, currently trying with glassfish. To do so I created a simple application that I deployed to the server first to verify it's working (it doesn't).
Here is what I did so far:
Setup a Ubuntu Virtual Machine in Oracle VirtualBox
download glassfish as zip-file and unzip it in the home directory
start glassfish
deploy the JSF-app as war-file
go to the page of the app: localhost:8080/jsftest/index.jsf
try to set a variable saved in session/application scope
Depending on javax.faces.STATE_SAVING_METHOD in web.xml the result:
server: viewExpiredException is thrown
client: value is not stored and default value is shown
To create the app I did the following:
create new dynamic web project in eclipse
unzip all files from myfaces core in WEB-INF/lib
set the classes-folder to WEB-INF/classes
write beans and a .xhtml as below
The session scoped bean (application scoped is similiar):
#ManagedBean(name = "sessbean")
#SessionScoped
public class MySessionScopeBean implements Serializable{
private static final long serialVersionUID = -4733271400646173098L;
private String value = "default session data";
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
}
The index.xhtml:
<?xml version="1.0" encoding="UTF-8"?>
<!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:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
<title>JSF 2.0 Hello World</title>
</h:head>
<h:body>
<h3>JSF 2.0 Hello World Example - hello.xhtml</h3>
<h:outputText value="Session id: #{sessionScope['id']}" />
<h:form>
<h:panelGroup>
<h:outputText value="Session Variable:"/>
<br/>
<h:inputText value="#{sessbean.value}"/>
</h:panelGroup>
<h:commandButton value="submit"/>
</h:form>
<h:form>
<h:panelGroup>
<h:outputText value="Application Variable:"/>
<br/>
<h:inputText value="#{appbean.value}"/>
</h:panelGroup>
<h:commandButton value="submit"/>
</h:form>
</h:body>
</html>
So this very basic example doesn't work. Any suggestions?
Also the Session-ID is not shown by #{sessionScope['id']}, don't know if that is the way to do it.
Got it working by removing parts of the (generated) web.xml file. The working file looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
<display-name>jsftest</display-name>
<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>*.jsf</url-pattern>
</servlet-mapping>
</web-app>
What I stripped out (don't know which part caused the failure):
<context-param>
<param-name>javax.servlet.jsp.jstl.fmt.localizationContext</param-name>
<param-value>resources.application</param-value>
</context-param>
<context-param>
<description>State saving method: 'client' or 'server' (=default). See JSF Specification 2.5.2</description>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
<context-param>
<description>
This parameter tells MyFaces if javascript code should be allowed in
the rendered HTML output.
If javascript is allowed, command_link anchors will have javascript code
that submits the corresponding form.
If javascript is not allowed, the state saving info and nested parameters
will be added as url parameters.
Default is 'true'</description>
<param-name>org.apache.myfaces.ALLOW_JAVASCRIPT</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<description>
If true, rendered HTML code will be formatted, so that it is 'human-readable'
i.e. additional line separators and whitespace will be written, that do not
influence the HTML code.
Default is 'true'</description>
<param-name>org.apache.myfaces.PRETTY_HTML</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>org.apache.myfaces.DETECT_JAVASCRIPT</param-name>
<param-value>false</param-value>
</context-param>
<context-param>
<description>
If true, a javascript function will be rendered that is able to restore the
former vertical scroll on every request. Convenient feature if you have pages
with long lists and you do not want the browser page to always jump to the top
if you trigger a link or button action that stays on the same page.
Default is 'false'
</description>
<param-name>org.apache.myfaces.AUTO_SCROLL</param-name>
<param-value>true</param-value>
</context-param>
<listener>
<listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class>
</listener>

tomcat7+El2.2+jsf1.2 not working

expression language is not working in tomcat7 with jsf1.2 .#{message.name_prompt} is ouputed as #{message.name_prompt}.
i tried to replace the el-api.jar in the tomcat lib folder with el-api-2.2.jar and put the el-impl-2.2.jar in the WEB-INF/lib folder, adding
<context-param>
<param-name>org.apache.myfaces.EXPRESSION_FACTORY</param-name>
<param-value>com.sun.el.ExpressionFactoryImpl</param-value>
</context-param>
to the web.xml. stilll the same.
my tomcat exact version is *7.0.21*this is the web.xml with the default tomcat setting:
<?xml version="1.0" encoding="UTF-8"?>
<web-app
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"
id="WebApp_ID" version="3.0">
<display-name>BasicExamples</display-name>
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>server</param-value>
</context-param>
<listener>
<listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class>
</listener>
<!-- Faces Servlet -->
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- Faces Servlet Mapping -->
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.jsf</url-pattern>
</servlet-mapping>
<login-config>
<auth-method>BASIC</auth-method>
</login-config>
</web-app>
update:
now i find that the expression language is not working on the form page but the message expression language is working as #{message.result_text}=>You entered the following information : ,but still managed bean not working.
and El is working fine with jsf2.0
You don't need to install/add anything to get EL 2.2 to work in Tomcat 7. It already ships with EL 2.2. Remove those JARs and the context param.
Given your symptoms
#{message.name_prompt} is ouputed as #{message.name_prompt}
I have the impression that you're talking about using EL in template text something like:
<p>This is EL in template text #{message.name_prompt}</p>
This is not an EL 2.2 feature. This is a Facelets feature. Facelets is the successor of JSP. You need to replace JSP by Facelets in order to be able to use EL in template text like that. For JSF 1.2, you can use Facelets 1.1.
Otherwise, when you want to stick to JSP, you really need to use <h:outputText>:
<p>This is EL in template text <h:outputText value="#{message.name_prompt}" /></p>
The only new EL 2.2 feature is the ability to invoke action methods with arguments, e.g.:
<h:dataTable value="#{bean.list}" var="item">
<h:column>
<h:commandButton value="Edit" action="#{bean.edit(item)}" />
</h:column>
</h:dataTable>
See also:
Difference between JSP EL, JSF EL and Unified EL
Migrating from JSF 1.2 to JSF 2.0

Resources