Question

我花了很多时间在无法设置托管bean问题的属性和阅读其他文章上，但仍然找不到问题。造成该问题的原因是什么？下面是StackTrace，newsLookupService和newsManager bean接口。

StackTrace：

*com.sun.faces.mgbean.ManagedBeanCreationException: Unable to set property newsLookupService for managed bean newsManager
at com.sun.faces.mgbean.ManagedBeanBuilder$BakedBeanProperty.set(ManagedBeanBuilder.java:615)
at com.sun.faces.mgbean.ManagedBeanBuilder.buildBean(ManagedBeanBuilder.java:133)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:257)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:117)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:94)
at org.apache.el.parser.AstValue.getValue(AstValue.java:137)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:190)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
at javax.faces.component.UIData.getValue(UIData.java:732)
at javax.faces.component.UIData.getDataModel(UIData.java:1822)
at javax.faces.component.UIData.setRowIndexWithoutRowStatePreserved(UIData.java:484)
at javax.faces.component.UIData.setRowIndex(UIData.java:473)
at com.sun.faces.renderkit.html_basic.TableRenderer.encodeBegin(TableRenderer.java:81)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
at javax.faces.component.UIData.encodeBegin(UIData.java:1133)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.ebd.login.filter.LoginAuthorizationFilter.doFilter(LoginAuthorizationFilter.java:40)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.faces.mgbean.ManagedBeanBuilder$BakedBeanProperty.set(ManagedBeanBuilder.java:606)
... 55 more

由以下原因引起：java.lang.NullPointerException 在com.ebd.news.beans.NewsLookupDatabaseBean.getAllNews（NewsLookupDatabaseBean.java:41）在com.ebd.news.beans.NewsManager.setNewsLookupService（NewsManager.java:51） ... 60更多*

newsLookupService：

package com.ebd.news.beans;
import java.util.List;
import com.ebd.news.jpa.News;
public interface NewsLookupService {
...
}

NewsManager.java：

package com.ebd.news.beans;

import java.io.Serializable;
import java.util.List;
...

Answer 1

只需澄清一下，webapp \ WEB-INF \ faces-config.xml中缺少的是：

<managed-bean>
    <managed-bean-name>newsManager</managed-bean-name>
    <managed-bean-class>com.ebd.news.beans.NewsManager</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>
</managed-bean>

IntelliJ编辑器没有看到newsManager，但是应用程序/ Tomcat没有。

无法为托管bean newsManager设置属性newsLookupService

1 个答案: