我正在使用JSF 2.0 ExcepctionHandler机制来处理我的应用程序中的所有异常。
public void handle() throws FacesException
{
FacesContext fc = FacesContext.getCurrentInstance();
for (Iterator<ExceptionQueuedEvent> i =
getUnhandledExceptionQueuedEvents().iterator(); i.hasNext();)
{
ExceptionQueuedEvent event = i.next();
ExceptionQueuedEventContext context =
(ExceptionQueuedEventContext)event.getSource();
// ... other treatments ...
final Application application = fc.getApplication();
final NavigationHandler navigationHandler =
application.getNavigationHandler();
navigationHandler.handleNavigation(fc, null, "error");
fc.renderResponse();
i.remove();
}
}
handleNavigation适用于几乎所有抛出的异常，但JSF bean实例中的错误除外。所有错误通常都会重定向到页面error.xhtml。
但是，在index.xhtml中我得到了这个：
<h:ouputText value="#{user.name}"/>
如果user构造函数抛出异常，我收到此错误：
javax.el.ELException: /index.xhtml: Cant instantiate class: com.test.user.bean.User.
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:90)
at com.sun.faces.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:82)
at com.sun.faces.facelets.compiler.UILeaf.encodeAll(UILeaf.java:183)
at org.richfaces.renderkit.RendererBase.renderChildren(RendererBase.java:276)
at org.richfaces.renderkit.html.PopupPanelRenderer.encodeEnd(PopupPanelRenderer.java:534)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:883)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1659)
at org.richfaces.renderkit.RendererBase.renderChildren(RendererBase.java:276)
at org.richfaces.renderkit.html.AjaxOutputPanelRenderer.encodeChildren(AjaxOutputPanelRenderer.java:57)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:853)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:304)
at com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:105)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:853)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1652)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:853)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1652)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1655)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1655)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:399)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:273)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:509)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:20654)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)
Caused by: com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class: com.test.user.bean.User.
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:61)
at org.apache.el.parser.AstValue.getValue(AstValue.java:107)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at com.sun.faces.facelets.el.ELText$ELTextVariable.writeText(ELText.java:224)
at com.sun.faces.facelets.el.ELText$ELTextComposite.writeText(ELText.java:148)
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:85)
... 61 more
在这种情况下，ExceptionHandler调用handleNavigation但没有任何反应，在浏览器中，这会导致空白页！
为什么这个异常不会像其他异常一样处理？
JSF 2.0.6（mojarra） RichFaces 4.1决赛 Tomcat 6.0.18 JDK 1.6.0_20