3 Replies Latest reply on May 19, 2009 4:26 PM by Robert Becker

    JbpmException: couldn't evaluate expression

    Robert Becker Newbie

      Hello everyone,


      in my processdefintion i have:


      <task-node name="consider request">
           <task name="consider license request">
                <description>
                     license_request_consider
                </description>
                <assignment pooled-actors="#{licenseRequestAssigner.approvers}"></assignment>
                <event type="task-start" >
                     <action expression="#{licenseRequestConsiderBean.prepare()}" />
                </event>
           </task>
           <transition to="acknowledge denial" name="denied"></transition>
           <transition to="acknowledge approval" name="approved"></transition>
      </task-node>



      and i have this bean:


      @Name("licenseRequestConsiderBean")
      @Scope(ScopeType.CONVERSATION)
      public class LicenseRequestConsiderBean {
      
          @In TaskInstance taskInstance;
      
          @Begin
          public String prepare() {
              System.out.println("--> Starting task");
              return "/admin/license/licenseRequestConsiderForm.xhtml";
          }
      ...



      But when i invoke task.start() jbpm throws this:


      org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
      javax.faces.el.EvaluationException: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:91)
              at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:91)
              at javax.faces.component.UICommand.broadcast(UICommand.java:383)
              at javax.faces.component.UIData.broadcast(UIData.java:854)
              at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:321)
              at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:296)
              at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:253)
              at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:466)
              at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
              at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
              at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
              at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
              at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:411)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:317)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:522)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:164)
              at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141)
              at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90)
              at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:406)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
              at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:522)
              at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
              at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:177)
              at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:267)
              at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:380)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:507)
              at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:288)
              at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:271)
              at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:202)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
              at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:206)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
              at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
              at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:150)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
              at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
              at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:272)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:637)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:568)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:813)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
              at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
              at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)
      Caused by: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:43)
              at org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:30)
              at org.jbpm.graph.def.Action.execute(Action.java:118)
              at org.jboss.seam.bpm.SeamUserCodeInterceptor$1.process(SeamUserCodeInterceptor.java:80)
              at org.jboss.seam.bpm.SeamUserCodeInterceptor$ContextualCall.run(SeamUserCodeInterceptor.java:33)
              at org.jboss.seam.bpm.SeamUserCodeInterceptor.executeAction(SeamUserCodeInterceptor.java:74)
              at org.jbpm.graph.def.GraphElement.executeAction(GraphElement.java:262)
              at org.jbpm.graph.def.GraphElement.executeActions(GraphElement.java:220)
              at org.jbpm.graph.def.GraphElement.fireAndPropagateEvent(GraphElement.java:190)
              at org.jbpm.graph.def.GraphElement.fireEvent(GraphElement.java:174)
              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 org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.invoke(CGLIBLazyInitializer.java:157)
              at org.jbpm.taskmgmt.def.Task$$EnhancerByCGLIB$$b216b68d.fireEvent(<generated>)
              at org.jbpm.taskmgmt.exe.TaskInstance.start(TaskInstance.java:329)
              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 org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:329)
              at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:274)
              at org.jboss.el.parser.AstMethodSuffix.getValue(AstMethodSuffix.java:59)
              at org.jboss.el.parser.AstMethodSuffix.invoke(AstMethodSuffix.java:65)
              at org.jboss.el.parser.AstValue.invoke(AstValue.java:96)
              at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
              at com.sun.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:68)
              at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:77)
              ... 85 more
      Caused by: org.jbpm.jpdl.el.ELException: Error evaluating ${licenseRequestConsiderBean.prepare()}; possible causes are logged at debug level
              at org.jboss.seam.bpm.SeamExpressionEvaluator$1.evaluate(SeamExpressionEvaluator.java:142)
              at org.jboss.seam.bpm.SeamExpressionEvaluator.evaluate(SeamExpressionEvaluator.java:45)
              at org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:39)
              ... 113 more
      #{task.start()}: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
      javax.faces.FacesException: #{task.start()}: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:107)
              at javax.faces.component.UICommand.broadcast(UICommand.java:383)
              at javax.faces.component.UIData.broadcast(UIData.java:854)
              at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:321)
              at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:296)
              at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:253)
              at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:466)
              at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
              at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
              at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
              at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
              at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:411)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:317)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:522)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:164)
              at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141)
              at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90)
              at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:406)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
              at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:522)
              at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
              at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:177)
              at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:267)
              at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:380)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:507)
              at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:288)
              at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:271)
              at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:202)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
              at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:206)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
              at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
              at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:150)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
              at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
              at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:272)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:637)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:568)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:813)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
              at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
              at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)
      Caused by: javax.faces.el.EvaluationException: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:91)
              at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:91)
              ... 84 more
      Caused by: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:43)
              at org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:30)
              at org.jbpm.graph.def.Action.execute(Action.java:118)
              at org.jboss.seam.bpm.SeamUserCodeInterceptor$1.process(SeamUserCodeInterceptor.java:80)
              at org.jboss.seam.bpm.SeamUserCodeInterceptor$ContextualCall.run(SeamUserCodeInterceptor.java:33)
              at org.jboss.seam.bpm.SeamUserCodeInterceptor.executeAction(SeamUserCodeInterceptor.java:74)
              at org.jbpm.graph.def.GraphElement.executeAction(GraphElement.java:262)
              at org.jbpm.graph.def.GraphElement.executeActions(GraphElement.java:220)
              at org.jbpm.graph.def.GraphElement.fireAndPropagateEvent(GraphElement.java:190)
              at org.jbpm.graph.def.GraphElement.fireEvent(GraphElement.java:174)
              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 org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.invoke(CGLIBLazyInitializer.java:157)
              at org.jbpm.taskmgmt.def.Task$$EnhancerByCGLIB$$b216b68d.fireEvent(<generated>)
              at org.jbpm.taskmgmt.exe.TaskInstance.start(TaskInstance.java:329)
              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 org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:329)
              at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:274)
              at org.jboss.el.parser.AstMethodSuffix.getValue(AstMethodSuffix.java:59)
              at org.jboss.el.parser.AstMethodSuffix.invoke(AstMethodSuffix.java:65)
              at org.jboss.el.parser.AstValue.invoke(AstValue.java:96)
              at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
              at com.sun.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:68)
              at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:77)
              ... 85 more
      Caused by: org.jbpm.jpdl.el.ELException: Error evaluating ${licenseRequestConsiderBean.prepare()}; possible causes are logged at debug level
              at org.jboss.seam.bpm.SeamExpressionEvaluator$1.evaluate(SeamExpressionEvaluator.java:142)
              at org.jboss.seam.bpm.SeamExpressionEvaluator.evaluate(SeamExpressionEvaluator.java:45)
              at org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:39)
              ... 113 more
      executePhase(INVOKE_APPLICATION 5,com.sun.faces.context.FacesContextImpl@709127c3) threw exception
      javax.faces.FacesException: #{task.start()}: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:105)
              at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
              at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
              at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
              at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:411)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:317)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:522)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:164)
              at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141)
              at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90)
              at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:406)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
              at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:522)
              at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
              at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:177)
              at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:267)
              at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:380)
              at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:507)
              at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
              at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
              at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
              at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
              at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
              at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:288)
              at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:271)
              at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:202)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
              at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:206)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
              at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
              at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:150)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
              at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
              at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
              at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
              at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:272)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:637)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:568)
              at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:813)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
              at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
              at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
              at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)
      Caused by: javax.faces.FacesException: #{task.start()}: org.jbpm.JbpmException: couldn't evaluate expression '#{licenseRequestConsiderBean.prepare()}'
              at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:107)
              at javax.faces.component.UICommand.broadcast(UICommand.java:383)
              at javax.faces.component.UIData.broadcast(UIData.java:854)
              at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:321)
              at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:296)
              at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:253)
              at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:466)
              at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
              ... 77 more
      ...
      



      What am i doing wrong?