我为我的JSF应用程序实现了HttpSessionListener。无法使用[1]参数找到方法[属性]
我有一个List<HttpSession>
所有活动会话的对象到我的应用程序。在每个SessionCreated Event上,我将实际的HttpSession
添加到List
。在登录时,我将一些属性添加到活动会话中,并替换List
中修改的会话。到目前为止,这很好,它工作。但是现在我创建了一个PrimeFaces数据表来显示哪个Session是一个未使用的Session。这意味着哪个会话没有登录属性。 Login属性是一个简单的String对象。
这里是DataTable的实现:
<p:dataTable var="sessions" value="#{applicationListener.sessions}" paginator="false" id="dt_sessions">
<f:facet name="header">
Sessions
</f:facet>
<p:column headerText="ID" style="font-size: 12px; text-align: center" >
#{sessions.id}
</p:column>
<p:column headerText="Name" style="font-size: 12px; text-align: center" >
#{sessions.attribute(login)}
</p:column>
</p:dataTable>
的Tomcat抛出一个HTTP 500堆栈跟踪:
Feb 6, 2013 2:00:50 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [] threw exception [/rmlcon.xhtml: Unable to find method [attribute] with [1] parameters] with root cause
javax.el.ELException: /rmlcon.xhtml: Unable to find method [attribute] with [1] parameters
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:88)
at com.sun.faces.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:82)
at com.sun.faces.facelets.compiler.UILeaf.encodeAll(UILeaf.java:183)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at org.primefaces.component.datatable.DataTableRenderer.encodeRegularCell(DataTableRenderer.java:741)
at org.primefaces.component.datatable.DataTableRenderer.encodeRow(DataTableRenderer.java:693)
at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:601)
at org.primefaces.component.datatable.DataTableRenderer.encodeRegularTable(DataTableRenderer.java:220)
at org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:192)
at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:74)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:424)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:124)
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.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
我真的不明白为什么它被抛出。请有人能解释我的错误吗?
谢谢。
谢谢。请注意:并非每次NetBeans的自动完成功能都是构建表达式的最佳方式。我遵循你的建议,并改变了我的代码。 – commandcraxx
任何想法,为什么我需要这样的引号'#{sessions.getAttribute(“login”)}'?否则,收到bean的参数是空字符串。使用Tomcat7。 –
@Panu:在OP的情况下,'login'是一个包含实际属性键的变量。你显然没有这样的变量,它实际上是属性键本身。然后你应该通过引用它来对属性键进行“硬编码”。顺便说一下,通常使用单引号,因为它在HTML/JSF标签属性内工作得更好,而这些属性本身通常用双引号括起来。 – BalusC