Question

I have an error-page directive which redirect all exception to an error display page

My web.xml:

<web-app [...]>
    [...]
    <error-page>
        <exception-type>java.lang.Exception</exception-type>
        <location>/view/error.xhtml</location>
    </error-page>
</web-app>

It works for almost any exception but today I noticed that sometimes and JSF error is logged and the exception is not handled (i.e., there is no redirection to the error page).

Here what I have in the log:

javax.enterprise.resource.webcontainer.jsf.context || JSF1073: javax.faces.event.AbortProcessingException caught during processing of INVOKE_APPLICATION 5 : UIComponent-ClientId=searchForm:j_idt147, Message=/view/listView.xhtml @217,7 actionListener="#{listController.nextPageClicked}": java.lang.NullPointerException
javax.enterprise.resource.webcontainer.jsf.context || /view/listView.xhtml @217,7 actionListener="#{listController.nextPageClicked}": java.lang.NullPointerException
javax.faces.event.AbortProcessingException: /view/listView.xhtml @217,7 actionListener="#{listController.nextPageClicked}": java.lang.NullPointerException
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:182)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:769)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.doChainInvoke(StandardPipeline.java:600)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:96)
    at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:174)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
    at java.lang.Thread.run(Thread.java:680)
Caused by: java.lang.NullPointerException
    at ch.ethz.id.wai.web.controller.ListController.nextPageClicked(ListController.java:410)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)

How can I also handle these exceptions?

Edit: by handle I don’t mean that I want to correct the problem causing the exception (which is another topic) but my question is how can I catch the exception in JSF with the <error-page> directive. An error page is visible, an entry in the log can be easily missed.

Answer 1

This is by design. When an actionListener method throws an exception, it will only be logged and not thrown. It’s "just" a listener intented for trivial preprocessing/logging tasks and such, not a real action. Only when an action method throws an exception, it will be delegated all the way to the container and end up in the default error page.

If you want to perform exception-sensitive business actions, do it in the action method instead.

See also:

• Differences between action and actionListener