将带有f：param的h：commandButton添加到h：dataTable时发生IllegalArgumentException

Question

Currently I'm using a datatable to display some items out of a database. Works fine.

<h:dataTable border="1" value="#{overviewBean.loadContent }" var="item" first="0" >
    <h:column id="column1">
        <f:facet name="header">
            <h:outputText value="#{messages.overviewSubscriptionID }"></h:outputText>
        </f:facet>
        <h:outputText value="#{item.subscriptionID }"></h:outputText>
    </h:column>
    <h:column id="column2">
        <f:facet name="header">
            <h:outputText value="#{messages.overviewCourseID}"></h:outputText>
        </f:facet>
        <h:outputText value="#{item.courseID }"></h:outputText>
    </h:column>
    ...
    <h:column id="column13">
        <f:facet name="header">
            <h:outputText value="#{messages.overviewDeleteItem }"></h:outputText>
        </f:facet>
        <h:commandButton action="#{overviewBean.delete}" value="X">
            <f:param name="delete" value="#{item.courseID}"></f:param>
        </h:commandButton>
    </h:column>
</h:dataTable>

Whenever now the param-tag is there, the page doesn't load. This is the exception that is thrown:

/overview.jsp(15,1) '#{overviewBean.loadContent }' java.lang.IllegalArgumentException
Caused by:
java.lang.IllegalArgumentException - java.lang.IllegalArgumentException

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Edit: Because requested, I added the entire stacktrace (as seen on the generated page):

 org.apache.jasper.el.JspELException: /overview.jsp(15,1) '#{overviewBean.loadContent }' java.lang.IllegalArgumentException at org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:107) at javax.faces.component.UIData.getValue(UIData.java:1142) at javax.faces.component.UIData.createDataModel(UIData.java:1082) at javax.faces.component.UIData.getDataModel(UIData.java:1056) at javax.faces.component.UIData.getRowCount(UIData.java:449) at org.apache.myfaces.shared_impl.renderkit.html.HtmlTableRendererBase.encodeInnerHtml(HtmlTableRendererBase.java:234) at org.apache.myfaces.shared_impl.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlTableRendererBase.java:143) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:627) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:250) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:257) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:257) at org.apache.myfaces.application.jsp.JspViewHandlerImpl.actuallyRenderView(JspViewHandlerImpl.java:427) at org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:383) at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:41) at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:140) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:187) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Thread.java:662) Caused by: javax.faces.el.EvaluationException: java.lang.IllegalArgumentException at org.apache.myfaces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:80) at org.apache.myfaces.el.convert.VariableResolverToELResolver.getValue(VariableResolverToELResolver.java:95) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54) at org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:142) at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:68) at org.apache.el.parser.AstValue.getValue(AstValue.java:112) at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186) at org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:101) ... 27 more Caused by: javax.el.ELException: java.lang.IllegalArgumentException at javax.el.BeanELResolver.setValue(BeanELResolver.java:116) at javax.el.CompositeELResolver.setValue(CompositeELResolver.java:69) at org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.setValue(FacesCompositeELResolver.java:182) at org.apache.myfaces.config.ManagedBeanBuilder.initializeProperties(ManagedBeanBuilder.java:268) at org.apache.myfaces.config.ManagedBeanBuilder.buildManagedBean(ManagedBeanBuilder.java:92) at org.apache.myfaces.el.unified.resolver.ManagedBeanResolver.createManagedBean(ManagedBeanResolver.java:198) at org.apache.myfaces.el.unified.resolver.ManagedBeanResolver.getValue(ManagedBeanResolver.java:164) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54) at org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:142) at org.apache.myfaces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:65) ... 34 more Caused by: java.lang.IllegalArgumentException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at javax.el.BeanELResolver.setValue(BeanELResolver.java:108) ... 43 more 

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Edit 2: Here's a link to the page that's actually generated: index_jsp.html

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Any idea? The bean is registered and otherwise working correctly. The method delete exists as well. (The column id's are correct, too)

Answer 1

Based on the stacktrace, you're using MyFaces. This might be MyFaces specific, I've never seen this on Mojarra, which I'm already using for years.

At least, using f:param in a h:commandButton wouldn't have worked on JSF 1.x anyway. It works on h:commandLink only. On the other hand, you should be wrapping the datatable's value in a DataModel so that you can obtain the row where the button was pressed. Alternatively, if you're on JSF 1.2, you can also use the f:setPropertyActionListener . You can find examples in this answer .