PrimeFaces 3.0 - 树在<p：dialog> </p：dialog> </p：tree>中的<p：tree>节点选择中的异常

Question

这个问题主要针对PrimeFaces开发团队，但也许其他人知道解决方法。我无法在PrimeFaces支持论坛上上传截图，但我可以在这里链接到我的问题。

在PrimeFaces支持论坛中报道： http://primefaces.prime.com.tr/forum/viewtopic.php?f=3&t=14022

我的网络应用中有<p:tree>设置了selection="single"模式。当<p:tree>不在<p:dialog>内时，节点选择正常工作，如下所示：

但是，当<p:tree>在对话框内时，每次在浏览器中单击节点时，服务器端都会抛出异常。选择永远不会在辅助bean上注册：

每次用户在浏览器中点击树节点时，我的服务器日志中会出现以下堆栈跟踪：

    27-Jul-2011 3:21:52 PM com.sun.faces.context.PartialViewContextImpl processPartial
INFO: java.lang.NullPointerException
java.lang.NullPointerException
    at org.primefaces.component.tree.TreeRenderer.decode(TreeRenderer.java:53)
    at javax.faces.component.UIComponentBase.decode(UIComponentBase.java:787)
    at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1181)
    at com.sun.faces.context.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:506)
    at com.sun.faces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:183)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1589)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at javax.faces.component.UIForm.visitTree(UIForm.java:344)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1600)
    at com.sun.faces.context.PartialViewContextImpl.processComponents(PartialViewContextImpl.java:376)
    at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:252)
    at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183)
    at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:931)
    at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:409)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79)
    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:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:399)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:317)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:204)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:311)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

以下是令人讨厌的PrimeFaces方法：

@Override
public void decode(FacesContext context, UIComponent component) {
    Tree tree = (Tree) component;
    Map<String,String> params = context.getExternalContext().getRequestParameterMap();
    String clientId = tree.getClientId(context);
    TreeModel model = new TreeModel((TreeNode) tree.getValue());

    if(tree.getSelectionMode() != null) {
        String selection = params.get(clientId + "_selection");

        String instantUnselection = params.get(clientId + "_instantUnselection");
        boolean isSingle = tree.getSelectionMode().equalsIgnoreCase("single");

        if(selection.equals("")) {
            if(isSingle)
                tree.setSelection(null);
            else
                tree.setSelection(new TreeNode[0]);
        }
        else {
            String[] selectedRowKeys = selection.split(",");

            if(isSingle) {
                TreeNode selectedNode = treeExplorer.findTreeNode(selectedRowKeys[0], model);
                tree.setSelection(selectedNode);
            }
            else {
                TreeNode[] selectedNodes = new TreeNode[selectedRowKeys.length];

                for(int i = 0 ; i < selectedRowKeys.length; i++) {
                    selectedNodes[i] = treeExplorer.findTreeNode(selectedRowKeys[i], model);
                    model.setRowIndex(-1);  //reset
                }

                tree.setSelection(selectedNodes);
            }
        }
    }

    decodeBehaviors(context, component);
}

导致异常的行是这一行：

        if(selection.equals("")) {

如果<p:tree>位于<p:dialog>内，则selection的值始终为null。

知道如何解决此问题吗？

我正在使用今天的每晚PF 3.0-M3-SNAPSHOT版本。 PF 3.0-M2也是如此。在IE 7和Firefox 4.0.1中都表现出相同的行为。

Answer 1

在PrimeFaces论坛上讨论。其他用户发现的类似问题。

Opened PrimeFaces issue ticket here.