Memory leak with ViewScoped bean?
In our JavaEE6 project (EJB3, JSF2) on JBoss 7.1.1, it seems we have a memory leak with SeamFaces @ViewScoped.
We made a little prototype to check the fact :
- we use JMeter to call a page 200 times;
- the page contains and calls a viewscoped bean which injects a stateful EJB;
- we fix the session timeout at 1 minute.
At the end of the test, we check the content of the memory with VisualVM, and here what we got:
- with a
@ViewScopedbean, we still get 200 instances of the statefulMyController- and the@PreDestroymethod is never called; - with a
@ConversationScopedbean,@preDestroymethod is called a the session end and then we got a clean memory.
Do we badly use the view scope, or is it truly a bug?
Here's the XHTML page:
<!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"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:s="http://jboss.org/seam/faces">
<f:metadata>
<f:viewParam name="u" value="#{myBean.uselessParam}" />
<s:viewAction action="#{myBean.callService}" />
</f:metadata>
<h:body >
<f:view>
</f:view>
</h:body>
</html>
Now the included bean myBean. For the @ConversationScoped variant, all commented parts are uncommented.
@ViewScoped
// @ConversationScoped
@Named
public class MyBean implements Serializable
{
@Inject
MyController myController;
//@Inject
//Conversation conversation;
private String uselessParam;
public void callService()
{
//if(conversation.isTransient())
//{
// conversation.begin();
//}
myController.call();
}
public String getUselessParam()
{
return uselessParam;
}
public void setUselessParam(String uselessParam)
{
this.uselessParam = uselessParam;
}
}
And then the injected stateful bean MyController:
@Stateful
@LocalBean
public class MyController
{
public void call()
{
System.out.println("call ");
}
@PreDestroy
public void destroy()
{
System.out.println("Destroy");
}
}
Answer
I see many developers are satisfied with @ViewAccessScoped in Myface CODI. Could you please give it a try and tell the feedback.