我正在开发一个JSF自定义组件,其目的是封装另一个组件(即PrimeFaces表格)并添加自定义行为。例如,它支持从基础数据或某些属性动态创建PrimeFaces列。此外,它还支持在XHTML中声明附加的PrimeFaces列,这些列也应添加到封装的PrimeFaces表格中。
考虑以下示例:
<my:table id="table" fields="title,label,value,additional">
<primefaces:column id="additional">
some content
</primefaces:column>
</my:table>
我的自定义组件在渲染时从fields
属性动态创建PrimeFaces列。然后将其所有的column
子元素移动到PrimeFaces表格中,所以在渲染完组件树后,它的样子如下:
my:table id="table"
|---primefaces:table id="table_table"
|---primefaces:column id="title"
|---primefaces:column id="label"
|---primefaces:column id="value"
|---primefaces:column id="additional"
在首次渲染时,这个工作正常。但是,当我执行组件的AJAX更新后,就会出现以下异常:javax.faces.FacesException: Cannot remove the same component twice: table:additional
at com.sun.faces.context.StateContext$DynamicAddRemoveListener.handleAddRemoveWithAutoPrune(StateContext.java:761)
at com.sun.faces.context.StateContext$DynamicAddRemoveListener.handleRemove(StateContext.java:629)
at com.sun.faces.context.StateContext$AddRemoveListener.processEvent(StateContext.java:342)
at com.sun.faces.context.StateContext$DynamicAddRemoveListener.processEvent(StateContext.java:565)
at javax.faces.event.SystemEvent.processListener(SystemEvent.java:108)
at javax.faces.event.ComponentSystemEvent.processListener(ComponentSystemEvent.java:118)
at com.sun.faces.application.ApplicationImpl.processListenersAccountingForAdds(ApplicationImpl.java:2218)
at com.sun.faces.application.ApplicationImpl.invokeViewListenersFor(ApplicationImpl.java:2036)
at com.sun.faces.application.ApplicationImpl.publishEvent(ApplicationImpl.java:290)
at com.sun.faces.application.ApplicationImpl.publishEvent(ApplicationImpl.java:245)
at javax.faces.application.ApplicationWrapper.publishEvent(ApplicationWrapper.java:726)
at javax.faces.component.UIComponentBase.disconnectFromView(UIComponentBase.java:2275)
at javax.faces.component.UIComponentBase.doPreRemoveProcessing(UIComponentBase.java:1939)
at javax.faces.component.UIComponentBase.setParent(UIComponentBase.java:437)
at javax.faces.component.UIComponentBase$ChildrenList.remove(UIComponentBase.java:2757)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.adjustIndexOfDynamicChildren(ComponentTagHandlerDelegateImpl.java:283)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:223)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at com.sun.faces.facelets.tag.ui.DefineHandler.applyDefinition(DefineHandler.java:106)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:206)
at com.sun.faces.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:395)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:366)
at com.sun.faces.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:111)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:202)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:194)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:312)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:371)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:350)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
at com.sun.faces.facelets.tag.ui.IncludeHandler.apply(IncludeHandler.java:124)
at com.sun.faces.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:116)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:202)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:202)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at com.sun.faces.facelets.tag.ui.DefineHandler.applyDefinition(DefineHandler.java:106)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:206)
at com.sun.faces.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:395)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:366)
at com.sun.faces.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:111)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:202)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:202)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at com.sun.faces.facelets.tag.jsf.core.ViewHandler.apply(ViewHandler.java:225)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:202)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:312)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:371)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:350)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:174)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:312)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:371)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:350)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:174)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
at com.sun.faces.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:161)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.buildView(FaceletViewHandlingStrategy.java:1006)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:99)
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:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at de.gebit.trend.servlet.security.AuthorizationFilter.doFilter(AuthorizationFilter.java:269)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:789)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
因此,只有从我的表移动到PrimeFaces表中的column
才会创建此错误。其他列不会被重新创建,因为在渲染期间,我使用存储在StateHelper
中的实例变量来指示列已经被创建。
我有点理解此异常的来源,并且知道它与JSF保存完整组件树有关,当JSF还原视图时,保存的状态与XHTML不一致。我不知道的是如何解决此问题。
请问有人能够向我解释状态保存机制的工作原理,特别是与动态添加子元素的结合使用以及如何避免此异常吗?
更新(2017年10月2日)
我创建了一个小的样本项目,没有使用之前使用的任何其他框架,可以在我的GitHub个人资料中找到。之前使用的一个主要框架正在处理安装在StateContext
中用于重放动态操作的AddRemoveListeners
。为了避免对我的问题产生影响并创建可复制的环境,我将其删除。
我现在观察到的行为略有不同(不再有异常),取决于是否启用/禁用部分状态保存以及我用于移动primefaces:column
的方法:
在所有情况下,表的第一次呈现都可以正常工作。然后,我通过提交分页请求执行后端请求。此时,行为在某些情况下是错误的。
启用部分状态保存
启用部分状态保存后,分页不起作用。我没有收到异常,但类似于以下警告:
Feb 10, 2017 4:33:11 PM com.sun.faces.application.view.FaceletPartialStateManagementStrategy saveDynamicActions
WARNUNG: Unable to save dynamic action with clientId 'form:table:table_table:additional' because the UIComponent cannot be found
此警告出现在动态创建或移动到primefaces:table
的每个组件中,或者是其中一个子组件。
禁用部分状态保存
禁用部分状态保存后,分页可以正常工作,但取决于何时移动自定义的primefaces:column
,会显示不同的行为。
在渲染响应阶段移动`column`
当在渲染响应阶段(如encodeXxx
)中移动primefaces:column
时,一切都正常工作。所有列都按正确顺序和正确值排列,并且分页正常工作。
使用`PostAddToViewEvent`移动`column`
根据@BalusC的建议,使用这种方法时,移动的primefaces:column
会在分页时消失。多次调用PostAddToViewEvent
,并且在处理此事件时移动column
,但是在渲染时,它已经消失,只剩下之前创建的三个column
。
此时,我已经感到非常困惑。这是Mojarra还是Primefaces中的一个错误,还是我做错了什么?这种行为在JSF中是否可能发生?
javax.faces.PARTIAL_STATE_SAVING
设置为false时,一切都按预期工作,不会出现异常。 - jessepeng<p:dataTable>
是动态创建的还是包含在<my:table>
中的? - BalusCUIComponent
实例不属于 JSF 状态。要么将其作为标签文件使用,例如<p:dataTable><ui:insert/></p:dataTable>
,要么让它继承自DataTable
。 - BalusC