Simple Example for Enums and selectOneRadio

[Don Esteban Cerrojo]

Hi to everybody,

I'm new in this forum and new to JSF. I have some experience in Java, JSP/Servlets but not very deep. My current environment is Eclipse Helios, Tomcat 7 and MyFaces 2. It took me a while arriving where I'm now . Before I had a look at Wicket and Google GWT/GAE. Hopefully I'll manage my project with the currently selected environment and technologies.

Until today, I made quite a bit of my road, but now I'm complete stuck with a very simple pattern. Using Enums in selectOneRadio. I can not even get a simple case working. Really frustrating. This I have done until now:

<h:form>
	<h:selectOneRadio value="#{testBean.myEnum}">
		<f:selectItem itemValue="#{AVALUE}" itemLabel="A Value" />
		<f:selectItem itemValue="#{ANOTHERVALUE}" itemLabel="Another Value" />
	</h:selectOneRadio>
	<h:commandButton value="to Console" action="#{testBean.value}"/>
</h:form>

@ManagedBean
@RequestScoped
public class TestBean implements Serializable {

	private static final long serialVersionUID = 1L;
	
	private MyEnum myEnum;

	public void setMyEnum(MyEnum myEnum) {
		this.myEnum = myEnum;
	}

	public MyEnum getMyEnum() {
		return myEnum;
	}

	public String value() {
		System.out.println(myEnum);
		return null;
	}


}

public enum MyEnum implements Serializable {
	AVALUE, ANOTHERVALUE, ANDONEMORE
}

Navigating to the test page throws a NullpointerException. I would appreciate a lot, if someone could correct/complete my example or present a working example at the same basic beginner level as I tried to figure out. Thanks a lot!

SCHWERWIEGEND: Error Rendering View[/intranet/test-my-enum.xhtml]
java.lang.NullPointerException
at org.apache.myfaces.shared_impl.renderkit.html.HtmlRadioRendererBase.renderGroupOrItemRadio(HtmlRadioRendererBase.java:213)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlRadioRendererBase.encodeEnd(HtmlRadioRendererBase.java:118)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:519)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:626)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage.renderView(FaceletViewDeclarationLanguage.java:1320)
at org.apache.myfaces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:263)
at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:85)
at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:239)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:191)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:306)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:550)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:380)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:243)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:288)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)
21.01.2011 19:53:13 org.apache.myfaces.renderkit.ErrorPageWriter handleThrowable
SCHWERWIEGEND: An exception occurred
javax.faces.FacesException: java.lang.NullPointerException
at org.apache.myfaces.shared_impl.context.ExceptionHandlerImpl.wrap(ExceptionHandlerImpl.java:241)
at org.apache.myfaces.shared_impl.context.ExceptionHandlerImpl.handle(ExceptionHandlerImpl.java:156)
at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:258)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:191)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:306)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:550)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:380)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:243)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:288)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)
Caused by: java.lang.NullPointerException
at org.apache.myfaces.shared_impl.renderkit.html.HtmlRadioRendererBase.renderGroupOrItemRadio(HtmlRadioRendererBase.java:213)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlRadioRendererBase.encodeEnd(HtmlRadioRendererBase.java:118)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:519)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:626)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage.renderView(FaceletViewDeclarationLanguage.java:1320)
at org.apache.myfaces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:263)
at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:85)
at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:239)
... 16 more

Thank You, regards
Don Esteban

[Don Esteban Cerrojo]

The problem described is partially resolved now. I changed Apache MyFaces against Oracles Mojarra impementation of JSF 2.0. Further I had to change the the lines

         <f:selectItem itemValue="#{AVALUE}" itemLabel="A Value" />  
         <f:selectItem itemValue="#{ANOTHERVALUE}" itemLabel="Another Value" />  

to

         <f:selectItem itemValue="AVALUE" itemLabel="A Value" />  
         <f:selectItem itemValue="ANOTHERVALUE" itemLabel="Another Value" />  

To make things clear. This working version with strings as itemValue properties was my first, intuitive approach to the the use of selectOneRadio components. It raised some EnumConverterException. Don't remember the exceptions name exactly. Anyhow it seems like an issue with Apache MyFaces. Strange that I didn't find anything by searching the Web.