p:commandButton results in an IllegalStateException [duplicate] - jsf-2

Question

This question already has answers here:
Adding <h:form> causes java.lang.IllegalStateException: Cannot create a session after the response has been committed
(5 answers)
Closed 7 years ago.
I get this error when I click on a p:commandButton in my page
java.lang.IllegalStateException: PWC3999: Cannot create a session
after the response has been committed
The button is in an h:form and looks like this:
<p:commandButton value="Save" action="#{discussionManager.save}" ajax="false"/>
But an h:commandButton works fine:
<h:commandButton value="Save" action="#{discussionManager.save}"/> (this works)
This is the bean with the method in it
#Named
#RequestScoped
public class DiscussionManager {
private static final Logger logger = Logger.getLogger("DiscussionManager");
#Inject
private DiscussionDao discussionDao;
private Discussion discussion = new Discussion();
#Produces
#Named
#RequestScoped
public Discussion getDiscussion() {
return discussion;
}
public String save() {
logger.info("Hello");
discussionDao.create(discussion);
return "list";
}
}
I've waited all day before posting this question because I feel like I should know how to get this working. But I've read and re-read my book, and loads of other posts. I just don't understand why it's not working.

Answer 1

I can't comment on your final answer so I have to add another answer. I believe what you did to make your example work was to add widgetVar to your editor component. I had this problem as well. The example on the PrimeFaces Demo wouldn't work properly until I added the widgetVar line. You need to reference the widgetVar name in your onclick call rather than the id. I use different names between the id and widgetVar for clarity so I would change your editor code to:
<h3>Write your message below</h3>
<p:editor id="editorID"
value="#{discussion.message}"
widgetVar="editorWidget"
width="600"
required="true"/>
<h:message for="editor"/>
<h:panelGrid columns="2" style="margin-top:10px">
<p:commandButton id="submitButton" value="Save" action="#{discussionManager.save}" ajax="false" icon="ui-icon-disk"/>
<p:commandButton id="clearButton" type="button" value="Clear" onclick="editorWidget.clear()" icon="ui-icon-close" />
</h:panelGrid>
I hope that helps clarify.

Answer 2

I suspect that it is because the bean goes out of scope. When you turn off ajax it submits the form and you are actually dealing with a new request. Try expanding your scope to a view scope.

Answer 3

Not quite sure what I changed to get it working, because now the whole thing is working fine. But for completeness, here's the relevant part of my page
<h3>Write your message below</h3>
<p:editor id="editor"
value="#{discussion.message}"
widgetVar="editor"
width="600"
required="true"/>
<h:message for="editor"/>
<h:panelGrid columns="2" style="margin-top:10px">
<p:commandButton id="submitButton" value="Save" action="#{discussionManager.save}" ajax="false" icon="ui-icon-disk"/>
<p:commandButton id="clearButton" type="button" value="Clear" onclick="editor.clear()" icon="ui-icon-close" />
</h:panelGrid>
And here's my bean. Hope someone finds this useful...
#Named
#RequestScoped
public class DiscussionManager implements Serializable {
private static final Logger logger = Logger.getLogger("DiscussionManager");
#Inject
private DiscussionDao discussionDao;
private Discussion discussion = new Discussion();
#Produces
#Named
#RequestScoped
public Discussion getDiscussion() {
return discussion;
}
public String save() {
logger.info("Hello");
discussionDao.create(discussion);
return "list";
}
}