PrettyFaces error: Exception occured while building URL for MappingId [...], Required value [...] was null

Question

Pages in my JSF project that rely on PrettyFaces for URL re-writing suddenly gave me the following error, despite my not having changed anything directly related to PrettyFaces. What gives?

PrettyFaces: Exception occurred while building URL for MappingId < my-page >, Required value  < #{myVar} > was null

Here is the full stack trace:

javax.enterprise.event.ObserverException
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at java.lang.Class.newInstance0(Class.java:355)
    at java.lang.Class.newInstance(Class.java:308)
    at org.jboss.weld.util.reflection.SecureReflections$16.work(SecureReflections.java:343)
    at org.jboss.weld.util.reflection.SecureReflectionAccess.run(SecureReflectionAccess.java:52)
    at org.jboss.weld.util.reflection.SecureReflectionAccess.runAsInstantiation(SecureReflectionAccess.java:173)
    at org.jboss.weld.util.reflection.SecureReflections.newInstance(SecureReflections.java:340)
    at org.jboss.weld.injection.Exceptions.rethrowException(Exceptions.java:33)
    at org.jboss.weld.injection.Exceptions.rethrowException(Exceptions.java:73)
    at org.jboss.weld.injection.MethodInjectionPoint.invokeOnInstanceWithSpecialValue(MethodInjectionPoint.java:162)
    at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:241)
    at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:229)
    at org.jboss.weld.event.ObserverMethodImpl.notify(ObserverMethodImpl.java:207)
    at org.jboss.weld.manager.BeanManagerImpl.notifyObservers(BeanManagerImpl.java:569)
    at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:559)
    at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:554)
    at org.jboss.solder.servlet.exception.CatchExceptionFilter.doFilter(CatchExceptionFilter.java:74)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at org.jboss.solder.servlet.event.ServletEventBridgeFilter.doFilter(ServletEventBridgeFilter.java:74)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
    at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    at org.apache.catalina.core.StandardHostValve.__invoke(StandardHostValve.java:161)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:849)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:746)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1045)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:228)
    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:662)
Caused by: javax.servlet.ServletException: PrettyFaces: Exception occurred while building URL for MappingId < my-page >, Required value  < #{myVar} > was null
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:606)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1542)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:343)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at com.ocpsoft.pretty.PrettyFilter.doFilter(PrettyFilter.java:145)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:807)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:671)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:505)
    at org.apache.catalina.core.ApplicationDispatcher.doDispatch(ApplicationDispatcher.java:476)
    at org.apache.catalina.core.ApplicationDispatcher.dispatch(ApplicationDispatcher.java:355)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:305)
    at com.ocpsoft.pretty.PrettyFilter.doFilter(PrettyFilter.java:137)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at org.jboss.solder.servlet.exception.CatchExceptionFilter.doFilter(CatchExceptionFilter.java:65)
    ... 30 more
Caused by: com.ocpsoft.pretty.PrettyException: PrettyFaces: Exception occurred while building URL for MappingId < my-page >, Required value  < #{myVar} > was null
    at com.ocpsoft.pretty.faces.beans.ExtractedValuesURLBuilder.buildURL(ExtractedValuesURLBuilder.java:69)
    at com.ocpsoft.pretty.faces.application.PrettyViewHandler.getActionURL(PrettyViewHandler.java:128)
    at javax.faces.application.ViewHandlerWrapper.getActionURL(ViewHandlerWrapper.java:185)
    at org.jboss.weld.jsf.ConversationAwareViewHandler.getActionURL(ConversationAwareViewHandler.java:100)
    at javax.faces.application.ViewHandlerWrapper.getActionURL(ViewHandlerWrapper.java:185)
    at com.sun.faces.renderkit.html_basic.FormRenderer.getActionStr(FormRenderer.java:232)
    at com.sun.faces.renderkit.html_basic.FormRenderer.encodeBegin(FormRenderer.java:135)
    at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:820)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:302)
    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:1757)
    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:1757)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
    at com.ocpsoft.pretty.faces.application.PrettyViewHandler.renderView(PrettyViewHandler.java:163)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:288)
    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)
    ... 46 more

score 1 · Accepted Answer · edited Jan 16 '13 at 18:47

1

This was due to a Converter, annotated with the @FacesConverter annotation, but without the value parameter. The project still deployed fine, and the PrettyFaces-mapped page in question did not use this (broken) converter, but this cryptic error still came up. In other words, I accidentally had:

@RequestScoped
@FacesConverter
public class MyConverter implements Converter {
//...

I replaced it with:

@RequestScoped
@FacesConverter("myConverter")
public class MyConverter implements Converter {
//...

and it worked. I hope this helps someone else!

edited Jan 16 '13 at 18:47

BalusC

992,635
352
3,478
3,452

answered Jan 15 '13 at 22:21

Nick

2,761
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39

1

This is likely because PrettyFaces builds URLs based on Bean Values in some cases. So if the value was null in your bean, it was likely null for PrettyFaces as well :) – Lincoln Jan 16 '13 at 15:45
Thanks @Lincoln; that's good to know; and it's always nice to have the official explanation! A little tangentially, do you happen to know why the `value` of `@FacesConverter` is mandatory, and isn't inferred from the class name (as opposed to `@Named`)? – Nick Jan 16 '13 at 18:47
1

The converter apparently returned a non-null default. By the way, `@RequestScoped` and `@FacesConverter` don't work together at all. They're used individually depending on how the converter is referenced. The former allows referencing converter via CDI as `converter="#{myConverter}"` and the latter via JSF as `converter="myConverter"` (which are completely separate instances!) See also e.g. http://stackoverflow.com/questions/7572335/dependency-injection-in-facesvalidator-jsf-validation – BalusC Jan 16 '13 at 18:47
@BalusC Thanks for the tip -- I did not mention that I am using Seam Faces, and was following their [recommendation to annotate converters with `@RequestScoped`](http://docs.jboss.org/seam/3/faces/latest/reference/en-US/html/artifacts.html#enhanced_artifacts) – Nick Jan 16 '13 at 18:52

PrettyFaces error: Exception occured while building URL for MappingId [...], Required value [...] was null

1 Answers1