Jakarta ee 尝试在EntityController中访问EntityHome返回nullpointer

我想将查询从EntityController中取出，并将其放入EntityHome组件中，但它会不断返回null指针。我无法找出错误，TransactionAttribute与此有关

控制员：

@Name("hElementController")
@Scope(ScopeType.CONVERSATION)
@AutoCreate
@BypassInterceptors
public class HElementController extends EntityController
{
 ...
    @In(create=true)
    private HElementHome hElementHome;

    ...
    @Transactional
    @TransactionAttribute(value = TransactionAttributeType.REQUIRES_NEW)
    public List<TreeNode> doSth(HClassifier classifier)
    {
    ...
        //hElementHome is null
        //nullpointer happens here
        List<Object[]> result = hElementHome.getElementsDTO(classifier.getId(), elementStatus);
    ...
    }
}

这很奇怪，因为stackstrace没有显示控制器调用hElementHome.getElementsDTO的确切时刻。。。在调试模式下，我可以看到hElementHome为null

---

我正在使用：Seam版本：2.2.2 Jboss 5.0.1

您的HElementController类已添加注释

@BypassInterceptors

---

因此，包括双射拦截器在内的Seam拦截器将不会在doSth方法执行时被调用，这意味着hElementHome将始终为null。您需要删除@BypassInterceptors，或者在doSth方法中使用component.getInstance获取对hElementHome组件的引用。根据您的应用程序体系结构，您可能需要要求Component.getInstance始终实例化该组件。请参阅javadocs或使用@AutoCreate注释HElementHome。

发布完整的堆栈跟踪，也许这对您有帮助。

new ComponentTest()
{
    protected void testComponents() throws Exception
    {
        HElementController hElementController = (HElementController)
        getValue("#{hElementController}");
        HElementHome hElementHome = (HElementHome)
        getValue("#{hElementHome}");
        ...

        List<TreeNode> actualList = hElementController.getElementsDTO(
            person1, 
            classifier1);
        ...

[http-127.0.0.1-9050-4] WARN org.hibernate.engine.StatefulPersistenceContext.ProxyWarnLog - Narrowing proxy to class com.m.youknow.model.Person - this operation breaks ==
[http-127.0.0.1-9050-2] WARN org.hibernate.engine.StatefulPersistenceContext.ProxyWarnLog - Narrowing proxy to class com.m.youknow.model.Person - this operation breaks ==
[http-127.0.0.1-9050-2] ERROR com.m.youknow.util.SignalViewHandler - Error Rendering View[/viewPerson.xhtml]
javax.faces.FacesException: javax.el.ELException: /include/inc_elementBreadCrumbDTO.xhtml @19,122 value="#{hElementController.getElementsDTO(classifier.id, elementStatus)}": java.lang.NullPointerException
at javax.faces.component.UIData.getValue(UIData.java:617)
at org.ajax4jsf.component.UIDataAdaptorBase.getValue(UIDataAdaptorBase.java:1647)
at org.ajax4jsf.component.SequenceDataAdaptor.getDataModel(SequenceDataAdaptor.java:65)
at org.ajax4jsf.component.SequenceDataAdaptor.createDataModel(SequenceDataAdaptor.java:59)
at org.ajax4jsf.component.UIDataAdaptorBase.getExtendedDataModel(UIDataAdaptorBase.java:621)
at org.ajax4jsf.component.UIDataAdaptorBase.setRowKey(UIDataAdaptorBase.java:339)
org.ajax4jsf.component.UIDataAdaptorBase.setRowKey(UIDataAdaptorBase.java:324)
org.ajax4jsf.renderkit.html.RepeatRenderer.encodeChildren(RepeatRenderer.java:63)
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)



Caused by: javax.el.ELException: /include/inc_elementBreadCrumbDTO.xhtml @19,122 value="#{hElementController.getElementsDTO(classifier.id, elementStatus)}":
java.lang.NullPointerException at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:76)
javax.faces.component.UIData.getValue(UIData.java:614)
... 90 more
 Caused by: java.lang.NullPointerException
com.m.youknow.element.HElementController.getElementsDTO(HElementController.java:95)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:335)
org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:280)
org.jboss.el.parser.AstMethodSuffix.getValue(AstMethodSuffix.java:59)
org.jboss.el.parser.AstValue.getValue(AstValue.java:67)
org.jboss.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
 ... 91 more



[lifecycle] JSF1054: (Phase ID: RENDER_RESPONSE 6, View ID: /viewPerson.xhtml) Exception thrown during phase execution: javax.faces.event.PhaseEvent[source=com.sun.faces.lifecycle.LifecycleImpl@9df9a2]
[[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception
java.lang.NullPointerException
at com.youknow.element.HElementController.doSth(HElementController.java:95)
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:335)
at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:280)
at org.jboss.el.parser.AstMethodSuffix.getValue(AstMethodSuffix.java:59)
at org.jboss.el.parser.AstValue.getValue(AstValue.java:67)
at org.jboss.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
at javax.faces.component.UIData.getValue(UIData.java:614)
at org.ajax4jsf.component.UIDataAdaptorBase.getValue(UIDataAdaptorBase.java:1647)
at org.ajax4jsf.component.SequenceDataAdaptor.getDataModel(SequenceDataAdaptor.java:65)
at org.ajax4jsf.component.SequenceDataAdaptor.createDataModel(SequenceDataAdaptor.java:59)
at org.ajax4jsf.component.UIDataAdaptorBase.getExtendedDataModel(UIDataAdaptorBase.java:621)
at org.ajax4jsf.component.UIDataAdaptorBase.setRowKey(UIDataAdaptorBase.java:339)
at org.ajax4jsf.component.UIDataAdaptorBase.setRowKey(UIDataAdaptorBase.java:324)
at org.ajax4jsf.renderkit.html.RepeatRenderer.encodeChildren(RepeatRenderer.java:63)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:234)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:239)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:239)
at com.sun.faces.renderkit.html_basic.TableRenderer.renderRow(TableRenderer.java:309)
at com.sun.faces.renderkit.html_basic.TableRenderer.encodeChildren(TableRenderer.java:133)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at org.jboss.seam.ui.util.cdk.RendererBase.renderChild(RendererBase.java:186)
at org.jboss.seam.ui.util.cdk.RendererBase.renderChildren(RendererBase.java:166)
at org.jboss.seam.ui.renderkit.CacheRendererBase.doEncodeChildren(CacheRendererBase.java:45)
at org.jboss.seam.ui.util.cdk.RendererBase.encodeChildren(RendererBase.java:92)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:148)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:100)
at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:176)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:110)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:266)
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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:638)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:444)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:382)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:310)
at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:195)
at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:159)
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:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.milestone.youknow.interceptor.TimeFilter.doFilter(TimeFilter.java:42)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
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$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:206)
at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:598)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:662)

@BypassInterceptors