webtier@glassfish.java.net

JSF2 parses EL expressions that are commented

From: <webtier_at_javadesktop.org>
Date: Thu, 25 Feb 2010 08:20:20 PST

Hi,

I have a page that looks roughly like the following:

[code]
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core">
    <h:head>
        <title>Main</title>
    </h:head>
    <h:body>
        <h:form prependId="false">
            <!--h:commandLink action="#{someBackingBean.logout}" value="logout" /-->
        </h:form>
    </h:body>
</html>
[/code]

I know the page is useless but I intentionally created it like this, so as not to clutter the example.

Please, pay attention to the fact that the EL expression is in a section that's commented out. So, it should not be evaluated.

When I try to display the page, however, I get an exception:

[code]
An Error Occurred:
The class 'com.testapp.web.SomeBackingBean_$$_javassist_55' does not have the property 'logout'.

javax.el.PropertyNotFoundException: The class 'com.testapp.web.SomeBackingBean_$$_javassist_55' does not have the property 'logout'.
        at javax.el.BeanELResolver.getBeanProperty(BeanELResolver.java:661)
        at javax.el.BeanELResolver.getValue(BeanELResolver.java:290)
        at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:175)
        at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
        at com.sun.el.parser.AstValue.getValue(AstValue.java:116)
        at com.sun.el.parser.AstValue.getValue(AstValue.java:163)
        at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
        at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:71)
        at com.sun.faces.facelets.el.ELText$ELTextVariable.toString(ELText.java:207)
        at com.sun.faces.facelets.el.ELText$ELTextComposite.toString(ELText.java:148)
        at com.sun.faces.facelets.compiler.CommentInstruction.write(CommentInstruction.java:70)
        at com.sun.faces.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:75)
        at com.sun.faces.facelets.compiler.UILeaf.encodeAll(UILeaf.java:176)
        at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
        at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:848)
        at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1613)
        at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
        at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
        at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:380)
        at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:126)
        at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:273)
        at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:127)
        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:313)
        at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
        at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
        at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
        at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:233)
        at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
        at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
        at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
        at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
        at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
        at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
        at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
        at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
        at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
        at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
        at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
        at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
        at java.lang.Thread.run(Thread.java:619)
[/code]


So, why does JSF attempt to evaluate EL expressions that are in comments?

Furthermore, the backing bean DOES have a logout method. And if I uncomment the code, it works. No exceptions. The property exists.
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