JSF ViewExpiredExceptionHandler NullPointerException

Я использую Apache MyFaces 2 на WebSphere Application Server 8. Я хочу реализовать собственный ExceptionHandler, который обрабатывает ViewExpiredException.

Я использую код, который BalusC опубликовал. Factory вызывается в нужное время, но я получаю исключение NullPointerException, когда здесь вызывается handleNavigation:

public class ViewExpiredExceptionHandler extends ExceptionHandlerWrapper {

    private ExceptionHandler wrapped;

    public ViewExpiredExceptionHandler(ExceptionHandler wrapped) {
        this.wrapped = wrapped;
    }


    @Override
    public void handle() throws FacesException {
        FacesContext facesContext = FacesContext.getCurrentInstance();

        for (Iterator<ExceptionQueuedEvent> iter = getUnhandledExceptionQueuedEvents()
                .iterator(); iter.hasNext();) {
            Throwable exception = iter.next().getContext().getException();

            if (exception instanceof ViewExpiredException) {
                facesContext
                        .getApplication()
                        .getNavigationHandler()
                        .handleNavigation(facesContext, null,
                                "/content/home?faces-redirect=true&expired=true");
                facesContext.renderResponse();
                iter.remove();
            }
        }

        getWrapped().handle();
    }

    @Override
    public ExceptionHandler getWrapped() {
        return wrapped;
    }

}

Исключение:

com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0068E: An exception was thrown by one of the service methods of the servlet [Faces Servlet] in application [My_App]. Exception created : [java.lang.NullPointerException
    at org.apache.myfaces.application.NavigationHandlerImpl.getNavigationCase(NavigationHandlerImpl.java:203)
    at org.apache.myfaces.application.NavigationHandlerImpl.handleNavigation(NavigationHandlerImpl.java:77)
    at myapp.ViewExpiredExceptionHandler.handle(ViewExpiredExceptionHandler.java:33)
    at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:191)
    at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1147)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:722)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:449)
    at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain.invokeTarget(WebAppFilterChain.java:125)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:92)
    at myapp.auth.RequestFilter.doFilter(RequestFilter.java:35)
    at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:192)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:89)
    at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:919)
    at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1016)
    at com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:87)
    at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:886)
    at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1655)
    at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:195)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:276)
    at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:214)
    at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:113)
    at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
    at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
    at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
    at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
    at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
    at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
    at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
    at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1650)
]

EDIT: Во-первых, /content — это каталог в моем WebContent. Это не контекстный путь. Я изменил свой код и использовал внешнее перенаправление следующим образом:

if (exception instanceof ViewExpiredException) {
        String loc = facesContext.getExternalContext()
            .getRequestServletPath();
        try {
            facesContext.getExternalContext().redirect(loc);
            //facesContext.getExternalContext().redirect("/content/home.xhtml");
            //facesContext.getExternalContext().redirect("/");
        } catch (IOException e) {
            e.printStackTrace();
        }
}

Но все равно получите то же исключение NullPointerException для FaceContext.getExternalContext().redirect. Но ExternalContext не является нулевым. Я получил RequestServletPath.

Так что не так с моим кодом здесь?

С уважением - veote