UrlBuilder.addValuesToParameter causes NPE

[ren-zhijun-oracle]

In JSF 2.2 it seems no longer possible to have null values for f:param. Consider this snipplet:

<h:link outcome="test" >
          <f:param name="x" value="#{null}"/>
</h:link>

Causes the following exception when the page is rendered initially:

Severe:   Error Rendering View[/test.xhtml]
java.lang.NullPointerException
	at java.net.URLEncoder.encode(URLEncoder.java:205)
	at com.sun.faces.context.UrlBuilder.addValuesToParameter(UrlBuilder.java:318)
	at com.sun.faces.context.UrlBuilder.addParameters(UrlBuilder.java:127)
	at com.sun.faces.context.ExternalContextImpl.encodeBookmarkableURL(ExternalContextImpl.java:1055)
	at javax.faces.context.ExternalContextWrapper.encodeBookmarkableURL(ExternalContextWrapper.java:966)
	at com.sun.faces.application.view.MultiViewHandler.getBookmarkableURL(MultiViewHandler.java:407)
	at javax.faces.application.ViewHandlerWrapper.getBookmarkableURL(ViewHandlerWrapper.java:272)
	at javax.faces.application.ViewHandlerWrapper.getBookmarkableURL(ViewHandlerWrapper.java:272)
	at org.jboss.weld.jsf.ConversationAwareViewHandler.getBookmarkableURL(ConversationAwareViewHandler.java:132)
	at javax.faces.application.ViewHandlerWrapper.getBookmarkableURL(ViewHandlerWrapper.java:272)
	at com.sun.faces.renderkit.html_basic.OutcomeTargetRenderer.getEncodedTargetURL(OutcomeTargetRenderer.java:194)
	at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.renderAsActive(OutcomeTargetLinkRenderer.java:158)
	at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.encodeBegin(OutcomeTargetLinkRenderer.java:96)
	at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
	at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
	at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
	at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
	at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
	at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
	at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
	at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
[..]

The code in UrlBuilder#addValuesToParameter seems to pass an unfiltered null value s to URLEncoder#encode. In JSF 2.1 this worked and null was simply converted to an empty value.

Affected Versions

[2.2.8]

[ren-zhijun-oracle]

@javaserverfaces Commented
Reported by frederickkaempfer

[ren-zhijun-oracle]

@javaserverfaces Commented
Issue-Links:
duplicates
#3158

[ren-zhijun-oracle]

@javaserverfaces Commented
@manfredriem said:
Closing this as this is a duplicate of an already diagnosed issue. Please see it for the reason why this unfortunately changed

[ren-zhijun-oracle]

@javaserverfaces Commented
Marked as duplicate on Tuesday, July 29th 2014, 6:05:11 am

[ren-zhijun-oracle]

@javaserverfaces Commented
frederickkaempfer said:
Thanks. Sorry I missed the previous reports.

Unfortunately this means that for each instance of f:param one has to make 100% sure that the EL expression never resolves to a null value while it is rendered which produces quite a lot of clutter in the code.

Additionally in the mentioned bug report I don't think your reasoning is correct with respect to the documentation of f:param. The value attribute of f:param is not required. So per spec it is perfectly legal to write:
code
<h:link outcome="test">
<f:param name="x" />
</h:link>
code

But this in fact is equivalent to having a #

{null}

value and produces the very same exception. In both cases for the runtime the value attribute is null.

The case of a null value definitely needs clarification in the spec (h:link), but the current behavior is not really acceptable.

[ren-zhijun-oracle]

@javaserverfaces Commented
agoncal said:
The way to pass the CDI conversation ID in HTTP GET is :

<h:link outcome="/newpage" value="Next">
  <f:param name="cid" value="#{javax.enterprise.context.conversation.id}"/>
</h:link>

But if the conversation has not been started yet, the conversation is null. So now, in JSF 2.2 I get a NPE.

How can I turn around this issue ?

[ren-zhijun-oracle]

@javaserverfaces Commented
This issue was imported from java.net JIRA JAVASERVERFACES-3355

[ren-zhijun-oracle]

• Issue Imported From: https://github.com/javaserverfaces/mojarra/issues/3359
• Original Issue Raised By:@javaserverfaces
• Original Issue Assigned To: @manfredriem
• Original Issue Closed By:@javaserverfaces

[BalusC]

reopening as this is definitely a mojarra bug