How to avoid BusyConversationException in jsf

Question

I'm getting BusyConversationException while navigating through pages in my jsf project. This mostly happens if the user tries to navigate to another page during an ajax call. This also happens when the user clicks on a link right after clicking on another link without waiting for loading of the page.

For example if the user clicks on more than one link which are generated through a code similar to below one we definitely get this exception. Another example is, lets say the user enter a query on a text field, and our application make an ajax call for searching this query. During that query if the user click on some button to navigate to another page BusyConversationException occurs too.

<h:commandLink value="#{theProfile.profileName}"
               title="#{theProfile.profileName}"
               action="#{profileBean.aProfileSelected}">
               <f:setPropertyActionListener target="#{currentProfileWebBean.theProfile}" value="#{theProfile}"/>
</h:commandLink>

I can catch this type of exception in an ExceptionHandler class which extends ExceptionHandlerWrapper class but I can't save my current state and the best I can do for this case is to redirect to main page when this exception occurs.

Is there any solution for avoiding this? Thanks in advance for answers and comments.

Answer 1

As mentioned in the other answers, this happens if an ajax request is still being processed or if an ajax event is triggered prior to the actual click on the submitting commandLink or commandButton (for instance by a change event on an input field).

Therfore it is not possible to avoid BusyConversationExceptions with onclick="preventEventPropagation(event)";, since the AJAX events are not triggered via propagation.

The issue can easily be avoided by listening for running ajax requests and blocking submits until the pending ajax events have been completed.

The issue and solution are explained in more detail in this blog post JSF2 AJAX/Submit conversation issue.