How to log specific exception if i am already using FullAjaxExceptionHandler - jsf

Question

I am using FullAjaxExceptionHandler to handle timeout issue in ajax request. The problem that I am facing is to handle javax.faces.view.facelets.FaceletException. If i have an error in the xhtml page, i dont want to show the stack trace instead show an error page. This i have achieved by specifying error page in web.xml. The problem is that i want to log this error. I am using log4j for other exceptions, but how to write handler for FaceletException. If write another Exception handler is there an order in which i should specify the handler class because i am already using FullAjaxExceptionHandler.
faces-config.xml:
<application>
<el-resolver>
org.springframework.web.jsf.el.SpringBeanFacesELResolver
</el-resolver>
</application>
<factory>
<exception-handler-factory>org.omnifaces.exceptionhandler.FullAjaxExceptionHandlerFactory</exception-handler-factory>
</factory>
<render-kit>
<renderer>
<component-family>org.primefaces</component-family>
<renderer-type>org.primefaces.component.ScheduleRenderer</renderer-type>
<renderer-class>com.example.domain.web.custom.MyScheduleRenderrer</renderer-class>
</renderer>
</render-kit>

Answer 1

Add a custom Exception handler factory in faces-config.xml
<application>
<el-resolver>
org.springframework.web.jsf.el.SpringBeanFacesELResolver
</el-resolver>
</application>
<factory>
<exception-handler-factory>com.fetchinglife.domain.web.permissions.CustomExceptionHandlerFactory</exception-handler-factory>
</factory>
Create custom exception handler factory
public class CustomExceptionHandlerFactory extends ExceptionHandlerFactory{
private ExceptionHandlerFactory wrapped;
public CustomExceptionHandlerFactory(ExceptionHandlerFactory wrapped) {
this.wrapped = wrapped;
}
#Override
public ExceptionHandler getExceptionHandler() {
return new CustomExceptionHandler(wrapped.getExceptionHandler());
}
#Override
public ExceptionHandlerFactory getWrapped() {
return wrapped;
}
}
Create custom exception handler
public class CustomExceptionHandler extends FullAjaxExceptionHandler{
static Logger log = Logger
.getLogger(CustomExceptionHandler.class);
public CustomExceptionHandler(ExceptionHandler wrapped) {
super(wrapped);
}
#Override
public void handle() throws FacesException {
Iterator<ExceptionQueuedEvent> unhandledExceptionQueuedEvents = getUnhandledExceptionQueuedEvents().iterator();
if(unhandledExceptionQueuedEvents.hasNext()){
Throwable exception = unhandledExceptionQueuedEvents.next().getContext().getException();
log.error("FL Error",exception);
}
super.handle();
}
}

Answer 2

Unfortunately, it appears that you can't have both.
From The JSF Spec, the ExceptionHandlerFactory is expecting a single type to be configured
From the source of the FullAjaxExceptionHandler, if the exception is non-ajax, it's rethrown, to be handled by the <error-page> mechanism.
You'll either have to extend or wrap the FullAjaxExceptionHandler to provide both Ajax and Non-Ajax exception handling