As i know,there are 4 ways to pass a parameter value from JSF page to backing bean :
- Method expression (JSF 2.0)
- f:param
- f:attribute
- f:setPropertyActionListener
Let see example one by one :
1. Method expression
Since JSF 2.0, you are allow to pass parameter value in the method expression like this #{bean.method(param)}.
JSF page…
<h:commandButton action="#{user.editAction(delete)}" />
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
public String editAction(String id) {
//id = "delete"
}
}
If you are deploy JSF application in servlet container like Tomcat, make sure you include the “el-impl-2.2.jar” properly. For detail, please read this article – JSF 2.0 method expression caused error in Tomcat.
2. f:param
Pass parameter value via f:param tag and get it back via request parameter in backing bean.
JSF page…
<h:commandButton action="#{user.editAction}">
<f:param name="action" value="delete" />
</h:commandButton>
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
public String editAction() {
Map<String,String> params =
FacesContext.getExternalContext().getRequestParameterMap();
String action = params.get("action");
//...
}
}
See a full f:param example here.
3. f:atribute
Pass parameter value via f:atribute tag and get it back via action listener in backing bean.
JSF page…
<h:commandButton action="#{user.editAction}" actionListener="#{user.attrListener}">
<f:attribute name="action" value="delete" />
</h:commandButton>
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
String action;
//action listener event
public void attrListener(ActionEvent event){
action = (String)event.getComponent().getAttributes().get("action");
}
public String editAction() {
//...
}
}
See a full f:attribute example here.
4. f:setPropertyActionListener
Pass parameter value via f:setPropertyActionListener tag, it will set the value directly into your backing bean property.
JSF page…
<h:commandButton action="#{user.editAction}" >
<f:setPropertyActionListener target="#{user.action}" value="delete" />
</h:commandButton>
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
public String action;
public void setAction(String action) {
this.action = action;
}
public String editAction() {
//now action property contains "delete"
}
}
See a full f:setPropertyActionListener example here.
P.S Please share your idea, if you have any other ways 🙂
Hello team,
I have following logic in xhtml, when loading page editbean.init() method will execute couple of minutes at that time dialog box should display with specified h:graphicImage, but not working.
Could you please help.
<html>
<h:body>
<h:form id=”form”>
<p:remoteCommand name=”rc” action=”#{editbean.init()}”
onstart=”PF(‘statusDialog’).show()”
oncomplete=”PF(‘statusDialog’).hide()” autoRun=”true”
process=”@this” partialSubmit=”true” />
</h:form>
<p:dialog widgetVar=”statusDialog” draggable=”false”
closable=”false” resizable=”false” showHeader=”false” modal=”true”>
<h:graphicImage name=”/images/loading.gif” />
</p:dialog>
</h:body>
</html>
Thanks in advance.
If anyone can help …
I have to take the tuple data from a table and insert it into the form. please
If anyone can help …
I have to take the tuple data from a table and insert it into the form.
This is not very interesting considering you are passing hardcoded values. The whole thing only gets complex when you want to pass for example the value of an input.
I cant get it to work, it’s incredible. All I want is a get request to a target view with the content of an input field. I am sitting here since TWO hours and I have NOT found a solution, this is seriously fucked up.
Hello everyone,
And if you want to use the data entered in a
as JasperReport step for availing the user you have entered ??
Thank you.
Hi thank’s for the explications
in my managedBean I have a method that needs parametres, and i want to get that parameter from an anther class.
so I do that :
but I get ejb exception, but when I give the value manualy ( ) it works
Thanks for helpful tutorial
Method expression:
cartBean :
public String addToCart(Product p) {
this.pro = p;
int index = -1;
for (ProductItem item : listProductItem) {
if(item.getProduct().getIdProduct()==p.getIdProduct()){
item.setQuantity(item.getQuantity()+1);
return “cartInfo”;
}
}
ProductItem i = new ProductItem();
i.setProduct(p);
i.setQuantity(1);
listProductItem.add(i);
return “cartInfo”;
}
WARNING: #{cartShopBean.addToCart(productInfoBean.product)}: java.lang.NullPointerException
javax.faces.FacesException: #{cartShopBean.addToCart(productInfoBean.product)}: java.lang.NullPointerException
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:118)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
… 26 more
Caused by: java.lang.NullPointerException
at controller.cartShopBean.addToCart(cartShopBean.java:67)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.el.parser.AstValue.invoke(AstValue.java:278)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:274)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
… 27 more
thg 12 26, 2014 12:56:51 SA com.sun.faces.context.AjaxExceptionHandlerImpl handlePartialResponseError
SEVERE: javax.faces.el.EvaluationException: java.lang.NullPointerException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at controller.cartShopBean.addToCart(cartShopBean.java:67)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.el.parser.AstValue.invoke(AstValue.java:278)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:274)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
… 27 more
Hi, can you please tell me why are we getting this kind of error ?
Comment demo
could you please tell me how can we populate the values of page1 to next page2. I new to JSF.. Please help!!
Can I pass Client side JS value in the param attribute ? For eg: Consider collecting values in JS array or JSON array at the client side. Can I pass those array values in the server side by parameter attribute ?
why copy paste? why? why?
before executing the page is showing error with red color below piece of code: Even The sample code i imported to my local machine ,it is not working plz get rid of me this problem
My Server is : jboss-as-7.1.1.Final
pom.xml is
4.0.0
com.mkyong.common
JavaServerFaces
war
1.0-SNAPSHOT
JavaServerFaces Maven Webapp
http://maven.apache.org
<!– For Java EE Application Server, uncomment this library
and comment the rest of the libraries
javax.faces
jsf-api
2.0
provided
–>
com.sun.faces
jsf-api
2.1.0-b03
com.sun.faces
jsf-impl
2.1.0-b03
org.glassfish.web
el-impl
2.2
javax.servlet
jstl
1.2
javax.servlet
javax.servlet-api
3.0.1
javax.servlet.jsp
jsp-api
2.1
<!– too old
com.sun.el
el-ri
1.0
–>
java.net.m2
java.net m2 repo
http://download.java.net/maven/2
JavaServerFaces
org.apache.maven.plugins
maven-compiler-plugin
2.3.1
1.6
1.6
ram why is your ram going out of order? clean it well
Map params =
FacesContext.getExternalContext().getRequestParameterMap();
Use this
Map params = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap();
true, hope that mkyong update the post.
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Can you update the first option to include the single quotes around the input parameter delete
I thing the 4th method is the best. Thank’s a lot for you. Also hidden forms may be used, but I don’t think it is a good idea.
*think
Hello friends, greets, Please I need send a Object that represent a POJO with getters and setters to other xhtml and this can see it in a datatable, bone I have a object person so var=person from datatable and showit in other datatable sending to bean or from other way, Please helpme and exuse me my english thanks. to everyone
Hello,
how can I parameterize a list with an “a4j:commandButton”?
thanks
Caio.
Is method 1 still valid and if yes can complex types be used?
e.g.
<h:commandButton action="#{user.addUser(user)}" />@ManagedBean(name="user") @SessionScoped public class UserBean{ public String addUser(User user) { //do something with the user } }Don’t seem to be able to get something like this working…
Thanks
I do use complex type using the first method and yes, it works for me
Please tell me about Difference between managed bean and backing bean?
There is not, they are the same thing
I don’t know why i used the first way, and i got following error:
javax.servlet.ServletException: /index.xhtml @47,103 action=”#{dbBean.getEditAction(list)}” Failed to parse the expression [#{dbBean.getEditAction(list)}]
javax.faces.webapp.FacesServlet.service(FacesServlet.java:606)
Please help me!
thank you very much.
Very nice post, Helpfull .
Keep writing .
Is possible use for the example below:
<h:outputText id="field1" value="#{myMB.methodWithParam('teste')}" />or
<h:inputText id="field1" value="#{myMB.methodWithParam('teste')}" />?
Thanks for your post.
I have the same question as you.
A simple bug
Method 1
Map params = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap();
Hi. Thanks for the post! Helped me out allready TWICE.
Examples 1,3 & 4 doesn’t work if the Bean’s uses the RequestScope. Did you any idea’s how to solve this without fetching the request param’s in the @PostConstruct method?
Thank you for this article! Really helped me 🙂
Do they have advantage one over the other, i mean if 1 can why 4 ways to do the same thing.
The most complicated variant I’ve successfully used is a call including a parameter from within a ui:include’d sub view (Method 1 + ui:include):
Client:
<ui:include src="..."> <ui:param name="documentId" value="#{doc.id}" /> <ui:param name="acceptButtonBean" value="#{repoHome}" /> <ui:param name="acceptButtonAction" value="removeIndividualDocument(documentId})" /> </ui:include>Sub view:
<h:commandButton value="Continue" action="#{acceptButtonBean[acceptButtonAction]}" /> ... </h:commandButton>This works great for lists that have a delete button to the right. HTH anybody
Please delete the above, it’s not working.
Before of getting mad trying to make EL 2 working in tomcat I would suggest this minor change:
Very nice post, bookmarked.
The change is in method 1, using quotation marks in the parameter.
action=”#{user.editAction(‘delete’)}
Nice resume!! before reading, I just knew the method expression!! thx
There are actually at least two other ways for specific situations, though both not extremely pretty.
Often the parameter you want to pass to a backing bean is an item from some iteration, e.g. a row from a data table. When your action method is executed, this row is directly available in the request scope under the name assigned to it on the page.
E.g. consider this code:
In your action method, you can now fetch “row” from the request scope and it will be the correct row on which the user clicked.
In this example, yet another way to get to the same thing is to make sure “model” is some JSF DataModel. In your action method, the current row of this model instance will then also point to the correct row.
All in all, I personally think method expressions with parameters are the clearest and most elegant solution.
I can’t see the code!
Hi,
Can you please write the code. I also tried to pass a value from an iteration to the action method but i couldn’t get the value in the action method. If i use a constant value as parameter, i can get it but if the parameter is from an iteration (dynamic value) then i can’t get it. (jsf 1.2 with icefaces 1.8.2).