Hello.

I'm a beginner in the world of Seam, and I currently got a little problem.
Actually, I'm not sure if it's Seam related or not, but since this forum already helped me a lot, I thought I could start by posting here anyway.

So I basically have an entity bean, 'Topic', with a OneToMany relation to himself.

public class Topic implements Serializable {

@OneToMany(cascade = CascadeType.ALL)
@MapKey
@Sort(type = SortType.NATURAL)
private SortedMap<String, Topic> children;
....

Basically, the goal is to have the list of every topics showed as a tree structure on the page.
So I simply find the root of all the topics, and start to recursively browse all the topics, but it just bugs directly after the root:

<ui:repeat var="topic" value="#{topicRoot.resultList}">
<h:outputText>#{topic.keycode}</h:outputText> <--still working here!
<ui:include src="recursionTestInclude.xhtml">
<ui:param name="node" value="#{topic}"/>
</ui:include>
<br/>
</ui:repeat>

the topicRoot is just and EntityQuery bean

Then the recursionTestInclude page...

<ui:repeat var="t" value="#{topic.children}">
<h:outputText value="#{t.keycode}"/>
</ui:repeat>

keycode is simple a property of topic, a String

The result is:

javax.faces.el.EvaluationException: /recursionTestInclude.xhtml @12,44 value="#{t.keycode}": Exception getting value of property keycode of base of type : org.hibernate.collection.PersistentSortedMap
at com.sun.facelets.el.LegacyValueBinding.getValue(LegacyValueBinding.java:60)
at javax.faces.component.UIOutput.getValue(UIOutput.java:77)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getStringValue(RendererUtils.java:217)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlTextRendererBase.renderOutput(HtmlTextRendererBase.java:69)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlTextRendererBase.encodeEnd(HtmlTextRendererBase.java:57)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:536)
at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:252)
at com.sun.facelets.component.RepeatRenderer.encodeChildren(RepeatRenderer.java:52)
at com.sun.facelets.component.UIRepeat.process(UIRepeat.java:357)
at com.sun.facelets.component.UIRepeat.encodeChildren(UIRepeat.java:617)
at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:244)
at com.sun.facelets.component.RepeatRenderer.encodeChildren(RepeatRenderer.java:52)
at com.sun.facelets.component.UIRepeat.process(UIRepeat.java:357)
at com.sun.facelets.component.UIRepeat.encodeChildren(UIRepeat.java:617)
at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:244)
at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:249)
at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:573)
at org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
at org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:229)
at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:384)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:138)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:63)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:57)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.debug.hot.HotDeployFilter.doFilter(HotDeployFilter.java:60)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:79)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.SeamFilter.doFilter(SeamFilter.java:84)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:96)
at org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:220)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.jboss.web.tomcat.tc5.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String
at java.lang.String.compareTo(String.java:92)
at java.util.TreeMap.getEntry(TreeMap.java:328)
at java.util.TreeMap.get(TreeMap.java:255)
at org.hibernate.collection.PersistentMap.get(PersistentMap.java:147)
at org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.java:78)
at com.sun.facelets.el.LegacyELContext$LegacyELResolver.getValue(LegacyELContext.java:141)
at com.sun.el.parser.AstValue.getValue(AstValue.java:125)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:195)
at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
at com.sun.facelets.el.LegacyValueBinding.getValue(LegacyValueBinding.java:56)
... 56 more

The final goal is of course to call recursively the recursionTestInclude page for each child.

Actually, I know that I'm doing it wrong, but I tried several different things without being capable of extracting that damn keycode (or anything else) from than children list.

Thank you.