title: javax.el.MethodNotFoundException: /index.xhtml @36,96 action="#{fattureBean.aggiorna()}": Method aggiorna not found
body: <p>I don't understand why Glassfish return me this error :</p>
  
  <pre><code>javax.faces.el.MethodNotFoundException: javax.el.MethodNotFoundException: /index.xhtml @36,96 action="#{fattureBean.aggiorna()}": Method aggiorna not found
      at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:92)
      at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
      at javax.faces.component.UICommand.broadcast(UICommand.java:315)
      at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
      at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
      at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
      at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
      at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
      at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
      at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
      at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
      at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
      at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
      at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
      at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
      at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
      at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
      at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
      at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
      at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
      at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
      at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
      at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
      at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
      at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
      at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
      at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
      at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
      at java.lang.Thread.run(Thread.java:722)
      Caused by: javax.el.MethodNotFoundException: /index.xhtml @36,96 action="#{fattureBean.aggiorna()}": Method aggiorna not found
      at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:109)
      at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
      ... 32 more
  </code></pre>
  
  <p>I call that method from a command button form :</p>
  
  <pre><code>&lt;h:form&gt;
      &lt;h:commandButton value="AGGIORNA DOCUMENTI" action="#{fattureBean.aggiorna()}"&gt;&lt;/h:commandButton&gt;
  &lt;/h:form&gt;
  </code></pre>
  
  <p>My backing bean is :</p>
  
  <pre><code>@ManagedBean
  @SessionScoped
  public class FattureBean implements Serializable{
  
      public String Aggiorna() throws SQLException {
          // ...
          return "index";
      }
  
      // ...
  }
  </code></pre>
  
  <p>I use NetBeans 7.3 with Glassfish 3.2 and JSF2.0. Where is my fault ? What's the right way to declare a method? Can a method throw an exception?</p>