發生ViewExpiredException時JSF錯誤頁面不顯示

Question

當頁面過期時查看時出現以下錯誤。該消息說Error page '/home.xhtml' will be shown.但實際上沒有顯示，頁面保持不變，而且它只是被凍結。我正在使用FullAjaxExceptionHandler從Omnifaces，由balusC描述。

我使用Primefaces 3.5和Mojarra 2.1.17。

Mär 11, 2013 1:40:30 PM org.apache.catalina.core.ApplicationContext log 
SEVERE: FullAjaxExceptionHandlerx: An exception occurred during processing JSF ajax request. Error page '/home.xhtml' will be shown. 
javax.faces.application.ViewExpiredException: viewId:/wishes_book.xhtml - View /wishes_book.xhtml could not be restored. 
    at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:205) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
    at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:116) 
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565) 
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1812) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    at java.lang.Thread.run(Thread.java:722) 
Mär 11, 2013 1:40:30 PM com.sun.faces.application.view.FaceletViewHandlingStrategy handleRenderException 
SEVERE: Error Rendering View[/home.xhtml] 
java.lang.NullPointerException 
    at org.primefaces.renderkit.CoreRenderer.getWidgetBuilder(CoreRenderer.java:481) 
    at org.primefaces.component.menubar.MenubarRenderer.encodeScript(MenubarRenderer.java:36) 
    at org.primefaces.component.menu.BaseMenuRenderer.encodeEnd(BaseMenuRenderer.java:40) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeRow(PanelGridRenderer.java:143) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeStaticBody(PanelGridRenderer.java:107) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeBody(PanelGridRenderer.java:63) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeEnd(PanelGridRenderer.java:49) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeRow(PanelGridRenderer.java:143) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeStaticBody(PanelGridRenderer.java:107) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeBody(PanelGridRenderer.java:63) 
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeEnd(PanelGridRenderer.java:49) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) 
    at com.sun.faces.context.PartialViewContextImpl.renderAll(PartialViewContextImpl.java:404) 
    at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:289) 
    at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183) 
    at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183) 
    at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:982) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779) 
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:411) 
    at com.meinanliegen.handlers.exceptions.FullAjaxExceptionHandler.renderErrorPageView(FullAjaxExceptionHandler.java:231) 
    at com.meinanliegen.handlers.exceptions.FullAjaxExceptionHandler.handleAjaxException(FullAjaxExceptionHandler.java:200) 
    at com.meinanliegen.handlers.exceptions.FullAjaxExceptionHandler.handle(FullAjaxExceptionHandler.java:145) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:119) 
    at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:116) 
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565) 
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1812) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    at java.lang.Thread.run(Thread.java:722) 
Mär 11, 2013 1:40:30 PM org.apache.catalina.core.StandardWrapperValve invoke 
SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/MeinAnliegen] threw exception 

你能幫我一個建議我怎麼能解決他的問題？

Answer 1

這是由PrimeFaces 3.5引起的。他們添加了一個PhaseListener，它在呈現響應階段創建並將WidgetBuilder作爲上下文屬性。然而，當處於渲染響應階段時，FullAjaxExceptionHandler強制直接渲染當前階段。這導致WidgetBuilder在對PrimeFaces組件進行編碼期間爲null，因此導致此NPE。此外，當前階段呈現響應時，它仍然不起作用，因爲FullAjaxExceptionHandler在呈現之前清理整個上下文屬性映射時有點過分（唯一的原因是強制重新注入JSF資源依賴項，例如CSS/JS文件），包括PrimeFaces WidgetBuilder。

這報告爲OmniFaces issue 120。 FullAjaxExceptionHandler已得到改進，以便在當前不處於呈現響應階段時將呈現委託給JSF，並僅從上下文屬性映射中移除特定屬性。您需要將OmniFaces更新至1.4（目前爲1.4.1），才能使其正常工作。