JSF Tomahawk tree2-提交（）时出现空指针错误？

我添加了一个JSF Tomahawk t:Tree2UI组件，页面呈现良好。但是，只要我在页面上执行任何操作：单击发送submit（）的按钮，或按设置了操作参数的按钮，就会报告错误：

java.lang.NullPointerException

viewId=/job.xhtml
location=trunk\tce\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\EWC\job.xhtml
phaseId=RESTORE_VIEW(1)

Caused by:
java.lang.NullPointerException
at org.apache.myfaces.custom.tree2.UITreeData.getDataModel(UITreeData.java:701)

以下是堆栈跟踪：

java.lang.NullPointerException
at org.apache.myfaces.custom.tree2.UITreeData.getDataModel(UITreeData.java:701)
at org.apache.myfaces.custom.tree2.UITreeData.setNodeId(UITreeData.java:387)
at org.apache.myfaces.custom.tree2.AbstractHtmlTree.setNodeId(AbstractHtmlTree.java:101)
at org.apache.myfaces.custom.tree2.UITreeData.visitTree(UITreeData.java:541)
at javax.faces.component.UIComponent.visitTree(UIComponent.java:958)
at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1073)
at javax.faces.component.UIData.visitTree(UIData.java:2169)
at javax.faces.component.UIForm.visitTree(UIForm.java:354)
at javax.faces.component.UIComponent.visitTree(UIComponent.java:958)
at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1073)
at org.apache.myfaces.lifecycle.DefaultRestoreViewSupport.processComponentBinding(DefaultRestoreViewSupport.java:105)
at org.apache.myfaces.lifecycle.RestoreViewExecutor.execute(RestoreViewExecutor.java:146)
at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:170)
at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:197)
at org.apache.myfaces.webapp.MyFacesServlet.service(MyFacesServlet.java:112)
at com.mainconcept.rews.webclient.controller.MyFacesServletWrapper.service(MyFacesServletWrapper.java:44)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:357)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
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:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1805)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

引发异常的位置在Begging，支持bean甚至不会再次实例化：

MyFacesServlet::service(ServletRequest request, ServletResponse response)

xhtml页面中的代码：

<h:dataTable value="#{JobMgmtBean.presetsTreesList}" var="presetsTree">
                                    <h:column>  

                                    <t:tree2  
                                              value             =   "#{presetsTree}" 
                                              var               =   "presetsTreeNode"
                                              varNodeToggler    =   "t" 
                                              showLines         =   "true" 
                                              showRootNode      =   "true"
                                              showNav           =   "true" 
                                              clientSideToggle  =   "true"
                                              preserveToggle    =   "true"> 

                                            <f:facet name="facetPresetTree">        
                                                <h:panelGroup>                  
                                                    <h:selectBooleanCheckbox     
                                                                                value               = "#{JobMgmtBean.idsT2[presetsTreeNode.identifier]}"
                                                                                title               = "#{presetsTreeNode.identifier}"
                                                                                valueChangeListener ="#{JobMgmtBean.setPresetsTreeNodeState}"
                                                                                />
                                                    <h:outputText value="#{presetsTreeNode.description}" styleClass="text"/>
                                                </h:panelGroup>                  
                                            </f:facet>
                                    </t:tree2>
                                    </h:column>
                                    </h:dataTable>

和相关bean成员：

protected List<TreeNodeChecked> presetsTreesList;
private HashMap<String, Boolean> idsT2;

受保护列表预置列表；
私有HashMap idsT2；

---

原因可能是什么

在jsf页面中显示添加的树的代码。。。这可能有助于（熟悉该组件的人）完成，使用jsf标记代码更新了问题。isnt value=“#{presetsTree}”应该指向bean本身的bean instad中的getter？否。请看第一行：var=“presetsTree”。所以，presetsTree不是一个bean，它是一个树列表。有没有可能您正在使用请求范围？如果是这样，请尝试更改会话范围，以查看问题是否。。。再看看这个。。。可能类似…在jsf页面中显示添加的树的代码。。。这可能有助于（熟悉该组件的人）完成，使用jsf标记代码更新了问题。isnt value=“#{presetsTree}”应该指向bean本身的bean instad中的getter？否。请看第一行：var=“presetsTree”。所以，presetsTree不是一个bean，它是一个树列表。有没有可能您正在使用请求范围？如果是这样，请尝试更改会话范围，以查看问题是否。。。再看看这个。。。可能是相似的。。。