在我的JSF应用程序的支持bean中，可能会在任何时候抛出某些异常，我想通过重定向到错误页面来对此作出反应。我添加了omnifaces FullAjaxExceptionHandler，我的web.xml包含
<error-page>
<exception-type>my.own.ResourceNotFoundException</exception-type>
<location>/error/error404.xhtml</location>
</error-page>
<error-page>
<error-code>500</error-code>
<location>/error/error500.xhtml</location>
</error-page>
在大多数情况下，包括Ajax请求，这很好用：ResourceNotFoundException引导我进入错误页面。但是，当在使用@PostConstruct注释的方法中抛出异常时，我总是得到错误代码500的通用页面。
这是因为JSF将异常包装在其他内容中，web.xml中的机制无法识别它吗？如果是，我怎样才能使其按预期工作？
以下是我在服务器日志中看到的异常跟踪：
Feb 07, 2013 11:08:32 AM com.sun.faces.application.view.FaceletViewHandlingStrategy handleRenderException
SEVERE: Error Rendering View[/my/projects/details/details.xhtml]
javax.el.ELException: //P:/codebase/code/portal/jsf-impl/target/classes/META-INF/resources/common/title.xhtml: Bei der Ressourcen-Einspeisung auf dem verwalteten Bean projectDetailsController ist ein Fehler aufgetreten.
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.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:302)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:309)
at com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:105)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779)
at com.sun.faces.renderkit.html_basic.CompositeRenderer.encodeChildren(CompositeRenderer.java:78)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:125)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:288)
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:594)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
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 my.own.filters.SecurityFilter.doFilter(SecurityFilter.java:48)
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:224)
at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:185)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.__invoke(StandardHostValve.java:151)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at my.own.UTF8Valve.invoke(UTF8Valve.java:34)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:269)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: com.sun.faces.mgbean.ManagedBeanCreationException: Bei der Ressourcen-Einspeisung auf dem verwalteten Bean projectDetailsController ist ein Fehler aufgetreten.
at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:229)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:105)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:71)
at org.apache.el.parser.AstValue.getValue(AstValue.java:147)
at org.apache.el.parser.AstDeferredExpression.getValue(AstDeferredExpression.java:44)
at org.apache.el.parser.AstCompositeExpression.getValue(AstCompositeExpression.java:50)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
at javax.faces.component.UIComponentBase$AttributesMap.get(UIComponentBase.java:2362)
at com.sun.faces.el.CompositeComponentAttributesELResolver$ExpressionEvalMap.get(CompositeComponentAttributesELResolver.java:345)
at javax.el.MapELResolver.getValue(MapELResolver.java:52)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at org.apache.el.parser.AstValue.getValue(AstValue.java:169)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
at com.sun.faces.facelets.el.ELText$ELTextVariable.writeText(ELText.java:227)
at com.sun.faces.facelets.el.ELText$ELTextComposite.writeText(ELText.java:150)
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:85)
... 43 more
Caused by: com.sun.faces.spi.InjectionProviderException
at com.sun.faces.vendor.WebContainerInjectionProvider.invokeAnnotatedMethod(WebContainerInjectionProvider.java:119)
at com.sun.faces.vendor.WebContainerInjectionProvider.invokePostConstruct(WebContainerInjectionProvider.java:99)
at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:223)
... 66 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.sun.faces.vendor.WebContainerInjectionProvider.invokeAnnotatedMethod(WebContainerInjectionProvider.java:117)
... 68 more
Caused by: my.own.ResourceNotFoundException: Did not find project
at my.own.projects.details.ProjectDetailsController.createModel(ProjectDetailsController.java:198)
答案 0 :(得分：1)
正如您的日志所示，ResourceNotFoundException包含在其他四个例外中。
您可以开发自己的CustomExceptionHandler，就像Duke's Forest example中的那个一样，而不是使用omnifaces FullAjaxExceptionHandler，甚至可以扩展它并向下运行，直到您到达ResourceNotFoundException然后使用NavigationHandler重定向到所需的错误页面。
以下是Duke's Forest示例中相关类和faces-config.xml的编辑版本。即使在@PostConstruct方法中发生异常，这应该按预期工作：
CustomExceptionHandlerFactory.java
package com.forest.exception;
public class CustomExceptionHandlerFactory extends ExceptionHandlerFactory {
private ExceptionHandlerFactory parent;
// this injection handles jsf
public CustomExceptionHandlerFactory(ExceptionHandlerFactory parent) {
this.parent = parent;
}
@Override
public ExceptionHandler getExceptionHandler() {
ExceptionHandler handler = new CustomExceptionHandler(parent.getExceptionHandler());
return handler;
}
}
CustomExceptionHandler.java
package com.forest.exception;
public class CustomExceptionHandler extends ExceptionHandlerWrapper {
private static final Logger log = Logger.getLogger(CustomExceptionHandler.class.getCanonicalName());
private ExceptionHandler wrapped;
CustomExceptionHandler(ExceptionHandler exception) {
this.wrapped = exception;
}
@Override
public ExceptionHandler getWrapped() {
return wrapped;
}
private boolean includesResourceNotFoundException(Throwable t) {
if(t == null) {
return false;
else {
return t instanceof ResourceNotFoundException || includesResourceNotFoundException(t.getCause());
}
}
@Override
public void handle() throws FacesException {
final Iterator<ExceptionQueuedEvent> i = getUnhandledExceptionQueuedEvents().iterator();
while (i.hasNext()) {
ExceptionQueuedEvent event = i.next();
ExceptionQueuedEventContext context =
(ExceptionQueuedEventContext) event.getSource();
// get the exception from context
Throwable t = context.getException();
final FacesContext fc = FacesContext.getCurrentInstance();
final Map<String, Object> requestMap = fc.getExternalContext().getRequestMap();
final NavigationHandler nav = fc.getApplication().getNavigationHandler();
//here you do what ever you want with exception
if(hasResourceNotFoundException(t) {
try {
//log error ?
log.log(Level.SEVERE, "Critical Exception!", t);
//redirect error page
requestMap.put("exceptionMessage", t.getMessage());
nav.handleNavigation(fc, null, "/error/error500?face-redirect=true");
fc.renderResponse();
} finally {
//remove it from queue
i.remove();
}
}
}
//parent hanle
getWrapped().handle();
}
}
faces-config.xml（部分）
<factory>
<exception-handler-factory>
com.forest.exception.CustomExceptionHandlerFactory
</exception-handler-factory>
</factory>