I rode that is recommended to use CDI beans as backing beans instead of JSF managed beans.
So i decided to create a little example, to understand how it works, for a #RequestScopedBean:
-instead of using #ManagedBean("beanName") ,i use #Named("beanName")
-instead of using javax.faces.bean.RequestScopped i use javax.enterprise.context.RequestScoped;
The demo program is very simple, i have a field and a submit button, when the user inputs something and the page is refreshed, the inputed value is not displayed anymore(It last while the request lasts right?). I think i did everything ok, but i get an exception that says:
WARNING: StandardWrapperValve[Faces
Servlet]: PWC1406: Servlet.service()
for servlet Faces Servlet threw
exception
javax.el.PropertyNotFoundException:
/index.xhtml #19,47
value="#{cdiBean.passedValue}": Target
Unreachable, identifier 'cdiBean'
resolved to null
This is how my program looks like:
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:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<h:head>
<title>RequestScope demo CDI(Component Dependency Injection)</title>
</h:head>
<h:body>
<h:form>
<h3>RequestScope demo CDI(Component Dependency Injection)</h3>
<h:inputText value="#{cdiBean.passedValue}"/>
<br/>
<h:commandButton value="submit" action="index"/>
</h:form>
</h:body>
</html>
DemoBB.java
package backingbeans;
import javax.enterprise.context.RequestScoped;
import javax.inject.Named;
#Named("cdiBean")//The Named anotation indicates that this is a CDI bean
#RequestScoped//If we use CDI beans the #RequestScoped annotation must come from: javax.enterprise.context.RequestScoped;
public class DemoBB {
//This value will be saved on the session only until the server responds to the request
private String passedValue;
public String getPassedValue() {
return passedValue;
}
public void setPassedValue(String passedValue) {
this.passedValue = passedValue;
}
}
-Where is my mistake?
-What is the advantage of using this approach? I still don't understand that.
Do you have an empty beans.xml along with your web.xml? I think it is mandatory to be there.
Read section 15.6 here. Quote from it:
CDI doesn't define any special
deployment archive. You can package
beans in JARs, EJB-JARs or WARs—any
deployment location in the application
classpath. However, the archive must
be a "bean archive". That means each
archive that contains beans must
include a file named beans.xml in the
META-INF directory of the classpath or
WEB-INF directory of the web root (for
WAR archives). The file may be empty.
Beans deployed in archives that do not
have a beans.xml file will not be
available for use in the application.
In an embeddable EJB container, beans
may be deployed in any location in
which EJBs may be deployed. Again,
each location must contain a beans.xml
file.
Related
I am using datatable on page and using binding attribute to bind it to my backing bean. This is my code :-
<?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:h="http://java.sun.com/jsf/html"
xmlns:p="http://primefaces.prime.com.tr/ui">
<h:head>
<title>Facelet Title</title>
</h:head>
<h:body>
<h:form prependId="false">
<h:dataTable var="item" value="#{testBean.stringCollection}" binding="#{testBean.dataTable}">
<h:column>
<h:outputText value="#{item}"/>
</h:column>
<h:column>
<h:commandButton value="Click" actionListener="#{testBean.action}"/>
</h:column>
</h:dataTable>
</h:form>
</h:body>
</html>
This is my bean :-
package managedBeans;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.faces.component.html.HtmlDataTable;
#ManagedBean(name="testBean")
#ViewScoped
public class testBean implements Serializable {
private List<String> stringCollection;
public List<String> getStringCollection() {
return stringCollection;
}
public void setStringCollection(List<String> stringCollection) {
this.stringCollection = stringCollection;
}
private HtmlDataTable dataTable;
public HtmlDataTable getDataTable() {
return dataTable;
}
public void setDataTable(HtmlDataTable dataTable) {
this.dataTable = dataTable;
}
#PostConstruct
public void init(){
System.out.println("Post Construct fired!!");
stringCollection = new ArrayList<String>();
stringCollection.add("a");
stringCollection.add("b");
stringCollection.add("c");
}
public void action(){
System.out.println("Clicked!!");
}
}
Please tell me why is the #PostConstruct firing each and every time i click on button? It should fire only once as long as i am on same page beacause my bean is #ViewScoped. Further, if i remove the binding attribute then everything works fine and #PostConstruct callback fires only once. Then why every time when i use binding attribute? I need binding attribute and want to perform initialisation tasks like fetching data from webservice, etc only once. What should i do? Where should i write my initialisation task?
Interesting, when you're using component binding on a view scoped bean, the view scope breaks.
I am not sure if that is a bug in JSF2, I would have to read the entire JSF2 specification first. As far now your best bet is to drop the component binding for now and pass the selected item via new EL 2.2 method argument syntax:
<h:dataTable var="item" value="#{testBean.stringCollection}">
<h:column>
<h:outputText value="#{item}"/>
</h:column>
<h:column>
<h:commandButton value="Click" action="#{testBean.action(item)}"/>
</h:column>
</h:dataTable>
See also:
How can I pass selected row to commandLink inside dataTable?
Invoke direct methods or methods with arguments / variables / parameters in EL
Benefits and pitfalls of #ViewScoped
Update (Dec 2012): this is indeed a bug in JSF2. It's a chicken-egg issue. The view scoped beans are stored in the JSF view state. So the view scoped beans are only available after restore view phase. However, the binding attribute runs during restore view phase, while the view scoped beans are not available yet. This causes creation of a brand new view scoped bean instance, which is then later replaced by the real view scoped bean which was stored in the restored JSF view state.
This is reported as JSF issue 1492 and JSF spec isssue 787 which will be fixed for JSF 2.2. Until then, your best bet is to use binding on request scoped beans exclusively, or to look for alternate ways for the particular functional requirement.
Update (Mar 2015): The JSF 2.2 fix was backported to Mojarra 2.1.18. So if you're still using JSF 2.0/2.1, you'd best upgrade to at least that version. See also a.o. What is component binding in JSF? When it is preferred to be used? and JSTL in JSF2 Facelets... makes sense?
As other said, I would say that the best thing to do is to drop component binding (you don't need it here).
But I would add that you can achieve the same as you're trying to do in a more object-oriented fashion by using action parameters, like this:
<h:commandButton value="Click" action="#{testBean.action(item)}"/>
... and in your java code:
public void action(Item item){
System.out.println("Clicked!!" + item);
}
If you have a viewscoped bean and if you want to retain values that were entered on the form or don't want postconstruct fired, you should return null from your action method.
If you return some outcome (e.g. invalid) and then point the invalid outcome to the same page using faces-config.xml, then the viewscoped bean gets recreated and thus it causes postconstruct to fire again.
Other solution:
Binding the HtmlDataTable in a request scope bean.
Inject this request scope bean in the view scope bean.
JBoss Seam use this solution for binding JSF componentes to a conversation scope component.
The balusc's answer helped me a lot, i would like to say that i had that bug with mojarra version 2.1.7, i am currently using 2.1.29-01 released in january-2015 and this bug is fixed, my problem was binding a tabview to a viewscoped bean. With this version I dont have that bug and binding and postconstruct is working fine.
I use Jboss 5.2 and i have to use mojarra 2.1.x so i hope this answer help other people in the same situation.
http://mvnrepository.com/artifact/com.sun.faces/jsf-api/2.1.29-01
http://mvnrepository.com/artifact/com.sun.faces/jsf-impl/2.1.29-01
I'm going through this Spring tutorial online form springsource.org.
http://static.springsource.org/docs/Spring-MVC-step-by-step/part2.html
In Chapter 2, at the end, it has you add a bean to prefix and suffix /WEB-INF/jsp/ and .jsp to responses.
The code so far should basically load index.jsp when you go to localhost:8080/springapp/ which will redirect to localhost:8080/springapp/hello.htm which creates an instance of the HelloController which should in theory send you over to /WEB-INF/jsp/hello.jsp. When I added the prefix/suffix bean and changed all my references to just "hello" instead of the fully pathed jsp file, I started getting the following error:
message Handler processing failed; nested exception is
java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/fmt/LocalizationContext
I've tried going back through the samples several times and checking for typo's and I still can't find the problem. Any tips or pointers?
index.jsp (in the root of the webapp:
<%# include file="/WEB-INF/jsp/include.jsp" %>
<%-- Redirected because we can't set the welcome page to a virtual URL. --%>
<c:redirect url="/hello.htm" />
HelloController.java (minus the imports and package:
public class HelloController implements Controller {
protected final Log logger = LogFactory.getLog(getClass());
public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String now = (new Date()).toString();
logger.info("Returning hello view with " + now);
return new ModelAndView("hello", "now", now);
}
}
My hello.jsp file:
<%# include file="/WEB-INF/jsp/include.jsp" %>
<!DOCTYPE html>
<html>
<head>
<title>Hello :: Spring Application</title>
</head>
<body>
<h1>Hello - Spring Application</h1>
<p>Greetings, it is now <c:out value="${now}" /></p>
</body>
</html>
It seems like you are missing the JSTL jar here. Try downloading it and place it in your classpath to see if it works: Where can I download JSTL jar
It seems certain required jar(s) are missing from classpath.
Make sure you have servlet-api-2.x.jar jsp-api-2.x.jar and jstl-1.x.jar on classpath
Please make sure the jstl.jar file is located in your WEB-INF/lib folder.
As a matter of fact, here is what is stated in the tutorial that you linked. I guess you missed this step:
We will be using the JSP Standard Tag Library (JSTL), so let's start
by copying the JSTL files we need to our 'WEB-INF/lib' directory. Copy
jstl.jar from the 'spring-framework-2.5/lib/j2ee' directory and
standard.jar from the 'spring-framework-2.5/lib/jakarta-taglibs'
directory to the 'springapp/war/WEB-INF/lib' directory.
I have backing bean like this:
#ManagedBean
#SessionScoped
public class TestBean {
private String testString;
public String getTestString() {
return testString;
}
public void setTestString(String testString) {
this.testString = testString;
}
}
And my xhtml page pretty simple too:
<?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:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
>
<h:head></h:head>
<h:body>
<h:form>
<h:inputText value="#{testBean.testString}"/>
<h:commandButton action="#{testController.testAction}"/>
</h:form>
</h:body>
</html>
Everything I want - to render my h:inputText element without value (empty).
I'm new to JSF, so, could you help me?
With best regards!
UPD!
It's simplified code, I'm using testString in other places and testString have value, which I want to hide! And I want to keep this value.
Provided that it's really a request/view scoped bean, you're likely victim of browser's builtin autocomplete/autofill feature. You can turn it off by adding autocomplete="off" to the input component in question.
<h:inputText ... autocomplete="off" />
Note again that it's not JSF who has filled the inputs, but the webbrowser itself. Clear the browser cache and you'll see that the browser won't do it anymore. Depending on browser make/version you can also reconfigure it to autocomplete a bit less eagerly.
Update: as per your question update, your bean turns out to be session scoped. This is not the normal scope for request/view based forms. A session scoped bean instance is shared across all browser windows/tabs (read: all requests/views) in the same HTTP session. You usually store only the logged-in user and its preferences (language, etc) in the session. You will only get a brand new instance when you shutdown and restart the entire browser, or use a different browser/machine.
Change it to be request or view scoped. In this particular simple example, the request scope should suffice:
#ManagedBean
#RequestScoped
See also:
How to choose the right bean scope?
Update 2 based on the comment,
Oh, you right, it's better for me to use #RequestScoped. But it doesn't resolve my problem - I want to keep this value, but I don;t want to show it in textInput. This value is important in context of request-response cycle.
the concrete functional requirement is now much more clear (in future questions, please pay attention to that while preparing the question, I had no idea that you was initially asking it like that). In that case, use a view scoped bean with 2 properties like this:
#ManagedBean
#ViewScoped
public class TestBean {
private String testString;
private String savedTestString;
public void testAction() {
savedTestString = testString;
testString = null;
}
// ...
}
You can alternatively also store it in the database or a property of an injected managed bean which is in turn actually in the session scope, for example.
You should bind the input text to some other field in your backing bean. And if you want to use that field for yourtestString, copy the entered value to testString in the testAction method.
<h:form>
<h:inputText value="#{testBean.copyTestString}"/>
<h:commandButton action="#{testController.testAction}"/>
</h:form>
public String testAction()
{
testString = copyTestString;
return "destinationPage";
}
Some Browsers ignore autocomplete - it can help to put autocomplete in form tag:
<h:form autocomplete="off">
This question already has answers here:
How to ajax-refresh dynamic include content by navigation menu? (JSF SPA)
(3 answers)
Closed 5 years ago.
I wrote this question:
https://stackoverflow.com/questions/8589315/jsf2-dynamic-template
but BalusC and casperOne told that i wrote it bad so I try to explain better my problem.
As I wrote, I have my project in this structure:
in web root 3 xhtml pages: index, include and welcome;
all others xhtml pages in a subfolder into WEB-INF called jsf.
I suppose that it is a good thing, but I create all pages using the netbeans' wizard "New JSF Pages From Entity Classes..." and for using this structure with this wizard, I can't link directly the xhtml pages saved into jsf forlder, as created by wizard, and I created the include.xhtml and modify all methods for redirecting to this page, as I will explain later, the include.xhtml contains only this code:
<?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:ui="http://java.sun.com/jsf/facelets"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
</h:head>
<h:body>
Utente connesso:<h:outputText value="#{userBean.cognome}"/>
<h:outputText value="#{userBean.nome}"/>
<br/&gr;
<ui:include src="#{logicBean.pageIncluded}"/>
</h:body>
</html>
As I said, I modified all methods to call action method in LogicBean that contains the setPageIncluded and return "include.xhtml" something like this:
PageController.java:
public void prepareList() {
recreateModel();
LogicBean l = (LogicBean) FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get("logicBean");
l.action(url+"List.xhtml");
}
LogicBean.java:
public String action(String value) {
setPageIncluded(value);
return "include";
}
Now this code works quite well and I can navigate from to all pages.
There is only a problem, the bean LogicBean is stored into the session!
This means that if I tried to open a new windows for navigate different part of the project in the same time I can't do that because LogicBean can contains only a single value of pageInclude!
I tried to use the ViewScope but or I don't understand how it works, and in this case it isn't useful, or I wrong something and it doesn't work properly!
Some one can help me?
I found this question that seems could help me:
dynamic ui:include with el-expression?
but I don't know if it could help and how modify the c:forEach and action method for using it for my situation!
I hope that this time I explain better my problem and, if it so, I thank you for help!
You use a JEE6 certified server, so you can use CDI for bean management. There is a CDI extension library called MyFaces CODI that has a Window scope bundle in it and you can use it to scope your beans instead of using session scope. This will solve your problem with the bean scoping.
Home page - http://myfaces.apache.org/extensions/cdi/
Does Facelets have any features for neater or more readable internationalised user interface text labels that what you can otherwise do using JSF?
For example, with plain JSF, using h:outputFormat is a very verbose way to interpolate variables in messages.
Clarification: I know that I can add a message file entry that looks like:
label.widget.count = You have a total of {0} widgets.
and display this (if I'm using Seam) with:
<h:outputFormat value="#{messages['label.widget.count']}">
<f:param value="#{widgetCount}"/>
</h:outputFormat>
but that's a lot of clutter to output one sentence - just the sort of thing that gives JSF a bad name.
Since you're using Seam, you can use EL in the messages file.
Property:
label.widget.count = You have a total of #{widgetCount} widgets.
XHTML:
<h:outputFormat value="#{messages['label.widget.count']}" />
This still uses outputFormat, but is less verbose.
You could create your own faces tag library to make it less verbose, something like:
<ph:i18n key="label.widget.count" p0="#{widgetCount}"/>
Then create the taglib in your view dir: /components/ph.taglib.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE facelet-taglib PUBLIC "-//Sun Microsystems, Inc.//DTD Facelet Taglib 1.0//EN" "https://facelets.dev.java.net/source/browse/*checkout*/facelets/src/etc/facelet-taglib_1_0.dtd">
<facelet-taglib xmlns="http://java.sun.com/JSF/Facelet">
<namespace>http://peterhilton.com/core</namespace>
<tag>
<tag-name>i18n</tag-name>
<source>i18n.xhtml</source>
</tag>
</facelet-taglib>
create /components/i18n.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">
<ui:composition 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">
<h:outputFormat value="#{messages[key]}">
<!-- crude but it works -->
<f:param value="#{p0}" />
<f:param value="#{p1}" />
<f:param value="#{p2}" />
<f:param value="#{p3}" />
</h:outputFormat>
</ui:composition>
You can probably find an elegant way of passing the arguments with a little research.
Now register your new taglib in web.xml
<context-param>
<param-name>facelets.LIBRARIES</param-name>
<param-value>
/components/ph.taglib.xml
</param-value>
</context-param>
Just add xmlns:ph="http://peterhilton.com/core" to your views and you're all set!
I've never come across another way of doing it other than outputFormat. It is unfortunately quite verbose.
The only other thing I can suggest is creating the message in a backing bean and then outputting that rather than messageFormat.
In my case I have Spring's MessageSource integrated with JSF (using MessageSourcePropertyResolver). Then, it's fairly easy in your backing beans to get parameterised messages - you just need to know which Locale your user is in (again, I've got the Locale bound to a backing bean property so it's accessible via JSF or Java).
I think parameters - particular in messages - are one thing JSF could really do better!
I have been thinking about this more, and it occurs to me that I could probably write my own JSTL function that takes a message key and a variable number of parameters:
<h:outputText value="#{my:message('label.widget.count', widgetCount)}"/>
and if my message function HTML-encodes the result before output, I wouldn't even need to use the h:outputText
#{my:message('label.widget.count', widgetCount)}
You can use the Seam Interpolator:
<h:outputText value="#{interpolator.interpolate(messages['label.widget.count'], widgetCount)}"/>
It has #BypassInterceptors on it so the performance should be ok.
You can use the Bean directly if you interpolate the messages.
label.widget.count = You have a total of #{widgetCount} widgets.
label.welcome.message = Welcome to #{request.contextPath}!
label.welcome.url = Your path is ${pageContext.servletContext}.
${messages['label.widget.count']} is enougth.
This one works great using Spring:
package foo;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ExpressionFactory;
import javax.el.ResourceBundleELResolver;
import javax.faces.context.FacesContext;
import org.springframework.web.jsf.el.SpringBeanFacesELResolver;
public class ELResolver extends SpringBeanFacesELResolver {
private static final ExpressionFactory FACTORY = FacesContext
.getCurrentInstance().getApplication().getExpressionFactory();
private static final ResourceBundleELResolver RESOLVER = new ResourceBundleELResolver();
#Override
public Object getValue(ELContext elContext, Object base, Object property)
throws ELException {
Object result = super.getValue(elContext, base, property);
if (result == null) {
result = RESOLVER.getValue(elContext, base, property);
if (result instanceof String) {
String el = (String) result;
if (el.contains("${") | el.contains("#{")) {
result = FACTORY.createValueExpression(elContext, el,
String.class).getValue(elContext);
}
}
}
return result;
}
}
And...
You need to change the EL-Resolver in faces-config.xml from org.springframework.web.jsf.el.SpringBeanFacesELResolver to
Regards
<el-resolver>foo.ELResolver</el-resolver>
Use ResourceBundle and property files.