JSF：在调用@ViewScoped bean中的方法时的EvaluationException和NPE

时间：2010-10-27 16:06:49

标签： jsf evaluation

其他Java战士！
我有这个托管bean来处理名为RedesBean（NetworksBean）的Rede（网络）实体相关操作。我有三个页面来插入一个新网络：redes / nova.xhtml（new.xhtml），它基本上是一系列用于插入网络属性的输入字段和一个调用cadastraNova（）（createNew（））方法的commandButton。验证输入并计算一些值。然后cadastraNova（）方法返回到另一个页面，redes / confirma.xhtml（confirm.xhtml），显示每个属性的值和计算值，要求用户确认，然后调用另一个方法cadastraRede（）（createNetwork（） ）通过JPA将网络持久化到数据库 当我使用@RequestScoped时，不会在第二个和第三个视图之间保留这些值。当我使用@SessionScoped时，值会被保留，但我认为@ SessionScoped-ing这有点太多了。所以，经过一些谷歌搜索，我发现这个@ViewScoped注释，我认为完全符合我的情况。但问题出在这里：在第一个视图（redes / nova.xhtml）中单击commandButton之后，我得到一个由EvaluationException引起的NullPointerExcetption。调用cadastraNova（）方法，但无法评估bean属性值。相关代码发布在下面：

RedesBean.java 

package br.cefetmg.ccc.gerir.web;

// suppressed imports

/**
 * Bean to manage network and subnetwork views
 * @author Arthur Alkmim
 *
 */
@ManagedBean(name="redes")
@ViewScoped
public class RedesBean implements Serializable{
 @EJB
 transient RedeDAO redeDAO;

 private static final Logger logger = Logger.getLogger("br.cefetmg.ccc.gerir.web.RedesBean");

 // attributes, suppressed

 // getters and setters, suppressed

 // the "broken" method
 public String cadastraNova(){
  logger.info("Method cadastraNova() successfully invoked");
  // verifica se a rede não já existe
  if(redeDAO.buscaPorId(ipBase) != null){
   FacesContext.getCurrentInstance().addMessage("Rede já existente", new FacesMessage("Já existe uma rede com esse IP"));
   return FacesContext.getCurrentInstance().getViewRoot().getViewId();
  }
  calculaAtributos();
  // verifica se o range de lease é válido
  if(!validaRange())
   // volta para a página de cadastro
   return FacesContext.getCurrentInstance().getViewRoot().getViewId();
  return "/redes/confirma";
 }
 // other suppressed methods
}

REDES / nova.xhtml 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"
 xmlns:ui="http://java.sun.com/jsf/facelets"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:ccc="http://java.sun.com/jsf/composite/compz">
<ui:composition template="/resources/estilo/template.xhtml">
 <f:loadBundle var="msg" basename="br.cefetmg.ccc.gerir.web.AppResources"/>
 <ui:define name="title">Nova rede</ui:define>
 <ui:define name="content">
  <h:form id="form">
   <h3>Principal</h3>
   <h:panelGrid columns="2" id="principal">
    <h:outputText value="Nome da rede" />
    <h:inputText value="#{redes.nome}" id="nome" />

    <h:outputText value="IP" />
    <h:panelGroup id="ip">
     <ccc:inputOneIP ip="#{redes.ipBase}" id="ipBase" />
     /
     <h:inputText value="#{redes.cidr}" size="2" id="cidr" validatorMessage="O CIDR deve estar entre 0 e 32">
      <f:validateLongRange minimum="0" maximum="32"/>
     </h:inputText>
    </h:panelGroup>
   </h:panelGrid>
   <h3>Servidores</h3>
   <h:panelGrid columns="2">
    <h:outputText value="Router" />
    <ccc:inputManyIP ip="#{redes.routers}" id="routers" />

    <h:outputText value="DNS" />
    <ccc:inputManyIP ip="#{redes.dns}" id="dns" />

    <h:outputText value="Netbios" />
    <ccc:inputManyIP ip="#{redes.netbios}" id="netbios" />
   </h:panelGrid>
   <h3>Lease</h3>
   <h:panelGrid columns="2">
    <h:outputText value="Tempo default" />
    <h:inputText value="#{redes.leaseDefault}" id="leaseDefault">
     <f:validateLongRange minimum="0" />
    </h:inputText>

    <h:outputText value="Tempo máximo" />
    <h:inputText value="#{redes.leaseMax}" id="leaseMax">
     <f:validateLongRange minimum="0" />
    </h:inputText>

    <h:outputText value="Início da faixa" />
    <ccc:inputOneIP ip="#{redes.rangeMin}" id="rangeMin" />

    <h:outputText value="Fim da faixa" />
    <ccc:inputOneIP ip="#{redes.rangeMax}" id="rangeMax" />
   </h:panelGrid>
   <h:commandButton action="#{redes.cadastraNova}" value="Cadastra"/>
  </h:form>
 </ui:define>
</ui:composition>
</html>

REDES / confirma.xhtml 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"
 xmlns:ui="http://java.sun.com/jsf/facelets"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:ccc="http://java.sun.com/jsf/composite/compz">

<ui:composition template="/resources/estilo/template.xhtml">
 <f:loadBundle var="msg" basename="br.cefetmg.ccc.gerir.web.AppResources"/>
 <ui:define name="title">Nova rede</ui:define>
 <ui:define name="content">
  <h:form id="form">
   Nome: <h:outputText value="#{redes.nome}" /><br />
   <ccc:outputOneIP ip="#{redes.ipBase}" />/<h:outputText value="#{redes.cidr}" />
   (<ccc:outputOneIP ip="#{redes.ipMin}" /> a <ccc:outputOneIP ip="#{redes.ipMax}" />)<br />
   Broadcast em: <ccc:outputOneIP ip="#{redes.broadcast}" /> <br />
   Máscara de rede: <ccc:outputOneIP ip="#{redes.netmask}" /><br />
   Roteadores: <ccc:outputManyIP ip="#{redes.routers}" /><br />
   Servidores de DNS: <ccc:outputManyIP ip="#{redes.dns}"/><br />
   Servidores netbios: <ccc:outputManyIP ip="#{redes.netbios}"/><br />
   Tempo de lease padrão: <h:outputText value="#{redes.leaseDefault}"/><br />
   Tempo de lease máximo: <h:outputText value="#{redes.leaseMax}"/><br />
   Range do lease: <ccc:outputOneIP ip="#{redes.rangeMin}" /> a <ccc:outputOneIP ip="#{redes.rangeMax}" /><br />
   <br />
   Estes dados estão corretos?
   <h:commandButton action="#{redes.cadastraRede}" value="Sim" />
   <h:commandButton action="#{redes.cancelaCadastro}" value="Não" />
  </h:form>
 </ui:define>
</ui:composition>
</html>

服务器日志

[#|2010-10-27T13:55:07.713-0200|INFO|glassfish3.0.1|br.cefetmg.ccc.gerir.web.RedesBean|_ThreadID=31;_ThreadName=Thread-1;|Method cadastraNova() successfully invoked|#]

[#|2010-10-27T13:55:07.713-0200|SEVERE|glassfish3.0.1|javax.enterprise.resource.webcontainer.jsf.application|_ThreadID=31;_ThreadName=Thread-1;|java.lang.NullPointerException
javax.faces.el.EvaluationException: java.lang.NullPointerException
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:98)
 at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:98)
 at javax.faces.component.UICommand.broadcast(UICommand.java:311)
 at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781)
 at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246)
 at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
 at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
 at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
 at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
 at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
 at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
 at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
 at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
 at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
 at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
 at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
 at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
 at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
 at br.cefetmg.ccc.gerir.web.RedesBean.cadastraNova(RedesBean.java:231)
 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 com.sun.el.parser.AstValue.invoke(AstValue.java:234)
 at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
 at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:102)
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:84)
 ... 32 more
|#]

[#|2010-10-27T13:55:07.714-0200|WARNING|glassfish3.0.1|javax.enterprise.resource.webcontainer.jsf.lifecycle|_ThreadID=31;_ThreadName=Thread-1;|#{redes.cadastraNova}: java.lang.NullPointerException
javax.faces.FacesException: #{redes.cadastraNova}: java.lang.NullPointerException
 at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:114)
 at javax.faces.component.UICommand.broadcast(UICommand.java:311)
 at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781)
 at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246)
 at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
 at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
 at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
 at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
 at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
 at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
 at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
 at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
 at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
 at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
 at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
 at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
 at java.lang.Thread.run(Thread.java:662)
Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:98)
 at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:98)
 ... 31 more
Caused by: java.lang.NullPointerException
 at br.cefetmg.ccc.gerir.web.RedesBean.cadastraNova(RedesBean.java:231)
 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 com.sun.el.parser.AstValue.invoke(AstValue.java:234)
 at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
 at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:102)
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:84)
 ... 32 more
|#]

[#|2010-10-27T13:55:07.715-0200|WARNING|glassfish3.0.1|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=31;_ThreadName=Thread-1;|StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
javax.faces.el.EvaluationException: java.lang.NullPointerException
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:98)
 at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:98)
 at javax.faces.component.UICommand.broadcast(UICommand.java:311)
 at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781)
 at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246)
 at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
 at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
 at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
 at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
 at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
 at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
 at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
 at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
 at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
 at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
 at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
 at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
 at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
 at br.cefetmg.ccc.gerir.web.RedesBean.cadastraNova(RedesBean.java:231)
 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 com.sun.el.parser.AstValue.invoke(AstValue.java:234)
 at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
 at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:102)
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:84)
 ... 32 more
|#]

[#|2010-10-27T13:55:07.715-0200|WARNING|glassfish3.0.1|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=31;_ThreadName=http-thread-pool-8080-(2);|StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
javax.faces.el.EvaluationException: java.lang.NullPointerException
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:98)
 at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:98)
 at javax.faces.component.UICommand.broadcast(UICommand.java:311)
 at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781)
 at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246)
 at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
     at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
 at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
 at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
 at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
 at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
 at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
 at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
 at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
 at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
 at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
 at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
 at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
 at br.cefetmg.ccc.gerir.web.RedesBean.cadastraNova(RedesBean.java:231)
 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 com.sun.el.parser.AstValue.invoke(AstValue.java:234)
 at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
 at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:102)
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:84)
 ... 32 more
|#]

[#|2010-10-27T13:55:07.715-0200|WARNING|glassfish3.0.1|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=31;_ThreadName=http-thread-pool-8080-(2);|StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
javax.faces.el.EvaluationException: java.lang.NullPointerException
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:98)
 at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:98)
 at javax.faces.component.UICommand.broadcast(UICommand.java:311)
 at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781)
 at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246)
 at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
 at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
 at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
 at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
 at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
 at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
 at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
 at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
 at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
 at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
 at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
 at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
 at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
 at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
 at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
 at br.cefetmg.ccc.gerir.web.RedesBean.cadastraNova(RedesBean.java:231)
 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 com.sun.el.parser.AstValue.invoke(AstValue.java:234)
 at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
 at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:102)
 at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:84)
 ... 32 more
|#]

因此，正如大家们所看到的，该方法实际上是由日志第一行中的记录器输出调用的。该方法在评估可能未更新的属性时失败。那么，如何解决？

2 个答案:

答案 0 :(得分：2)

到目前为止，您显示的方法代码段中null唯一可以redeDAO为transient。因为它标记为transient我认为服务器被配置为立即（通过序列化）在磁盘上存储视图/会话，而不是一直保存在内存中。声明为@EJB的任何内容都将在序列化过程中丢失，并且在反序列化后JSF无法为您重新注入它。

我建议将Serializable非瞬态（只是实现{{1}}）并重试。

答案 1 :(得分：1)

有点解决了。我从@ViewScoped更改为@ConversationScoped并使用CDI注释而不是JSF注释 - 即@Named和@Inject而不是@ManagedBean和@EJB。

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