我在使用 primefaces 中的“计划”组件将一些日期加载到日历中时遇到问题。这是我的 client.xhtml 的样子:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<body>
<ui:composition template="./PlanningTemplate.xhtml">
<ui:define name="top">
top
</ui:define>
<ui:define name="content">
<p:schedule id="schedule" value="#{scheduleController.eventModel}" widgetVar="myschedule">
<p:ajax event="dateSelect" listener="#{scheduleController.onDateSelect}" oncomplete="eventDialog.show()" />
<p:ajax event="eventSelect" listener="#{scheduleController.onEventSelect}" oncomplete="eventDialog.show()" />
<p:ajax event="eventMove" listener="#{scheduleController.onEventMove}" />
<p:ajax event="eventResize" listener="#{scheduleController.onEventResize}" />
</p:schedule>
<p:dialog widgetVar="eventDialog" header="Event Details" showEffect="clip" hideEffect="clip">
<h:panelGrid id="eventDetails" columns="2">
<h:outputLabel for="title" value="Title:" />
<p:inputText id="title" value="#{scheduleController.event.title}" required="true"/>
<h:outputLabel for="from" value="From:" />
<p:inputMask id="from" value="#{scheduleController.event.startDate}" mask="99/99/9999">
<f:convertDateTime pattern="dd/MM/yyyy" />
</p:inputMask>
<h:outputLabel for="to" value="To:" />
<p:inputMask id="to" value="#{scheduleController.event.endDate}" mask="99/99/9999">
<f:convertDateTime pattern="dd/MM/yyyy" />
</p:inputMask>
</h:panelGrid>
</p:dialog>
</ui:define>
<ui:define name="bottom">
bottom
</ui:define>
</ui:composition>
</body>
</html>
烘焙看起来像这样:
@Named(value = "scheduleController")
@SessionScoped
public class scheduleController implements Serializable {
@PersistenceContext(unitName="MajanTelepointagePU")
EntityManager em;
private ScheduleModel eventModel;
private ScheduleEvent event = new DefaultScheduleEvent() {};
List<Intervention> listOfAllInterventions = new ArrayList<Intervention>();
public scheduleController(){
eventModel = new DefaultScheduleModel();
// Load here the events into the eventModel via the method aventmodel.addEvent(title,startDate,endDate)
//get the list of all interventions
listOfAllInterventions = em.createNamedQuery("Intervention.findAll").getResultList();
for(Intervention i : listOfAllInterventions){
eventModel.addEvent(new DefaultScheduleEvent(i.getNotesGeneral(),i.getHeureDebut(),i.getHeureFin()));
}
}
public ScheduleModel getEventModel() {
return eventModel;
}
public void setEventModel(ScheduleModel eventModel) {
this.eventModel = eventModel;
}
public ScheduleEvent getEvent() {
return event;
}
public void setEvent(ScheduleEvent event) {
this.event = event;
}
public void addEvent(ActionEvent actionEvent) {
if(event.getId() == null) {
eventModel.addEvent(event); }
else {
eventModel.updateEvent(event); }
event = new DefaultScheduleEvent();
}
public void onEventSelect(SelectEvent selectEvent) {
event = (ScheduleEvent) selectEvent.getObject();
}
public void onDateSelect(SelectEvent selectEvent) {
event = new DefaultScheduleEvent("", (Date) selectEvent.getObject(), (Date) selectEvent.getObject());
}
public void onEventMove(ScheduleEntryMoveEvent event) {
FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO, "Event moved", "Day delta:" + event.getDayDelta() + ", Minute delta:" + event.getMinuteDelta());
addMessage(message);
}
public void onEventResize(ScheduleEntryResizeEvent event) {
FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO, "Event resized", "Day delta:" + event.getDayDelta() + ", Minute delta:" + event.getMinuteDelta());
addMessage(message);
}
private void addMessage(FacesMessage message) {
FacesContext.getCurrentInstance().addMessage(null, message);
}
}
但是 client.xhtml 没有运行，这里是异常的完整堆栈跟踪:
com.google.common.collect.ComputationException: java.lang.RuntimeException: java.lang.NullPointerException
at com.google.common.collect.ComputingConcurrentHashMap$ComputingMapAdapter.get(ComputingConcurrentHashMap.java:397)
at org.jboss.weld.bean.proxy.ClientProxyProvider.getClientProxy(ClientProxyProvider.java:102)
at org.jboss.weld.el.AbstractWeldELResolver.lookup(AbstractWeldELResolver.java:115)
at org.jboss.weld.el.AbstractWeldELResolver.getValue(AbstractWeldELResolver.java:96)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:188)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:103)
at com.sun.el.parser.AstValue.getValue(AstValue.java:179)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:224)
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
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.UIOutput.getValue(UIOutput.java:169)
at org.primefaces.util.ComponentUtils.getValueToRender(ComponentUtils.java:64)
at org.primefaces.component.inputtext.InputTextRenderer.encodeMarkup(InputTextRenderer.java:77)
at org.primefaces.component.inputtext.InputTextRenderer.encodeEnd(InputTextRenderer.java:51)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:312)
at com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:185)
at com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:129)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:59)
at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:47)
at org.primefaces.component.dialog.DialogRenderer.encodeContent(DialogRenderer.java:172)
at org.primefaces.component.dialog.DialogRenderer.encodeMarkup(DialogRenderer.java:101)
at org.primefaces.component.dialog.DialogRenderer.encodeEnd(DialogRenderer.java:43)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1764)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:288)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
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: java.lang.RuntimeException: java.lang.NullPointerException
at org.jboss.weld.util.reflection.SecureReflectionAccess.runAsInstantiation(SecureReflectionAccess.java:186)
at org.jboss.weld.util.reflection.SecureReflections.newInstance(SecureReflections.java:341)
at org.jboss.weld.bean.proxy.ProxyFactory.create(ProxyFactory.java:242)
at org.jboss.weld.bean.proxy.ClientProxyProvider.createClientProxy(ClientProxyProvider.java:87)
at org.jboss.weld.bean.proxy.ClientProxyProvider.access$000(ClientProxyProvider.java:43)
at org.jboss.weld.bean.proxy.ClientProxyProvider$1.apply(ClientProxyProvider.java:53)
at org.jboss.weld.bean.proxy.ClientProxyProvider$1.apply(ClientProxyProvider.java:46)
at com.google.common.collect.ComputingConcurrentHashMap$ComputingValueReference.compute(ComputingConcurrentHashMap.java:355)
at com.google.common.collect.ComputingConcurrentHashMap$ComputingSegment.compute(ComputingConcurrentHashMap.java:184)
at com.google.common.collect.ComputingConcurrentHashMap$ComputingSegment.getOrCompute(ComputingConcurrentHashMap.java:153)
at com.google.common.collect.ComputingConcurrentHashMap.getOrCompute(ComputingConcurrentHashMap.java:69)
at com.google.common.collect.ComputingConcurrentHashMap$ComputingMapAdapter.get(ComputingConcurrentHashMap.java:393)
... 62 more
Caused by: java.lang.NullPointerException
at MajanTelepointage.BB.scheduleController.<init>(scheduleController.java:48)
at MajanTelepointage.BB.scheduleController$Proxy$_$$_WeldClientProxy.<init>(scheduleController$Proxy$_$$_WeldClientProxy.java)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at java.lang.Class.newInstance0(Class.java:372)
at java.lang.Class.newInstance(Class.java:325)
at org.jboss.weld.util.reflection.SecureReflections$16.work(SecureReflections.java:344)
at org.jboss.weld.util.reflection.SecureReflectionAccess.run(SecureReflectionAccess.java:52)
at org.jboss.weld.util.reflection.SecureReflectionAccess.runAsInstantiation(SecureReflectionAccess.java:173)
... 73 more
更准确地说，错误引用了以下行:
listOfAllInterventions = em.createNamedQuery("Intervention.findAll").getResultList();
感谢您的帮助:)
最佳答案
您了解堆栈跟踪吗？这表明构造函数内的 em 为 null。您也可以直接这么说，而不是显示堆栈跟踪。 java.lang 包中的异常相当微不足道。
无论如何，注入(inject)的依赖项在构造函数中确实不可用。从技术上讲，不可能在构造实例之前设置实例字段的值。如果您想在实例构造之后直接处理注入(inject)的依赖项，那么您应该使用 @PostConstruct 带注释的方法。
替换
public scheduleController(){
由
@PostConstruct
public void init() {
并且em将在那里可用。
与具体问题无关，Java naming conventions规定类名必须以大写字母开头。请也努力解决这个问题。
关于java - 将事件从数据库加载到日历 primefaces，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16261344/