Question

我使用我在互联网上找到的代码来打开WST向导，该向导有助于创建新的XML文件。

public  void openWizard(String id) {
    // First see if this is a "new wizard".
    IWizardDescriptor descriptor = PlatformUI.getWorkbench()
      .getNewWizardRegistry().findWizard(id);
    // If not check if it is an "import wizard".
    if  (descriptor == null) {
      descriptor = PlatformUI.getWorkbench().getImportWizardRegistry()
      .findWizard(id);
    }
    // Or maybe an export wizard
    if  (descriptor == null) {
      descriptor = PlatformUI.getWorkbench().getExportWizardRegistry()
      .findWizard(id);
    }
    try  {

      // Then if we have a wizard, open it.
      if  (descriptor != null) {
        IWizard wizard = descriptor.createWizard();
        IWorkbenchWindow win = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
        WizardDialog wd = new  WizardDialog(win.getShell(), wizard);
        wd.setTitle(wizard.getWindowTitle());
        wd.open();


      }
    } catch  (CoreException e) {
      e.printStackTrace();
    }
   }

我还定义了向导的id：

String XML_WIZARD_ID= "org.eclipse.wst.xml.ui.internal.wizards.NewXMLWizard";

我将此函数称为：

openWizard(XML_WIZARD_ID);

这不起作用，并在Eclipse的内部代码中抛出java.lang.NullPointerException。

我想知道可能导致问题的原因。

这是堆栈跟踪：

java.lang.NullPointerException at org.eclipse.ui.dialogs.WizardNewFileCreationPage.initialPopulateContainerNameField（WizardNewFileCreationPage.java:688）在 org.eclipse.ui.dialogs.WizardNewFileCreationPage.createControl（WizardNewFileCreationPage.java:247）在 org.eclipse.wst.xml.ui.internal.wizards.NewModelWizard $ NewFilePage.createControl（NewModelWizard.java:283）在 org.eclipse.jface.wizard.Wizard.createPageControls（Wizard.java:174）在 org.eclipse.jface.wizard.WizardDialog.createPageControls（WizardDialog.java:736）在 org.eclipse.jface.wizard.WizardDialog.createContents（WizardDialog.java:608）在org.eclipse.jface.window.Window.create（Window.java:432）at org.eclipse.jface.dialogs.Dialog.create（Dialog.java:1104）at org.eclipse.jface.window.Window.open（Window.java:791）at org.eclipse.linuxtools.tmf.ui.views.xmlExplorer.XMLExplorerView.openWizard（XMLExplorerView.java:286）在 org.eclipse.linuxtools.tmf.ui.views.xmlExplorer.XMLExplorerView $ AddAction.run（XMLExplorerView.java:140）在org.eclipse.jface.action.Action.runWithEvent（Action.java:499）at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection（ActionContributionItem.java:584）在 org.eclipse.jface.action.ActionContributionItem.access $ 2（ActionContributionItem.java:501）在 org.eclipse.jface.action.ActionContributionItem $ 6.handleEvent（ActionContributionItem.java:452）在org.eclipse.swt.widgets.EventTable.sendEvent（EventTable.java:84）在org.eclipse.swt.widgets.Widget.sendEvent（Widget.java:1392）at org.eclipse.swt.widgets.Display.runDeferredEvents（Display.java:3742）在org.eclipse.swt.widgets.Display.readAndDispatch（Display.java:3363）在 org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine $ 9.run（PartRenderingEngine.java:1113）在 org.eclipse.core.databinding.observable.Realm.runWithDefault（Realm.java:332）在 org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run（PartRenderingEngine.java:997）在 org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI（E4Workbench.java:138）在org.eclipse.ui.internal.Workbench $ 5.run（Workbench.java:610）at org.eclipse.core.databinding.observable.Realm.runWithDefault（Realm.java:332）在 org.eclipse.ui.internal.Workbench.createAndRunWorkbench（Workbench.java:567）在 org.eclipse.ui.PlatformUI.createAndRunWorkbench（PlatformUI.java:150）在 org.eclipse.ui.internal.ide.application.IDEApplication.start（IDEApplication.java:124）在 org.eclipse.equinox.internal.app.EclipseAppHandle.run（EclipseAppHandle.java:196）在 org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication（EclipseAppLauncher.java:110）在 org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start（EclipseAppLauncher.java:79）在 org.eclipse.core.runtime.adaptor.EclipseStarter.run（EclipseStarter.java:354）在 org.eclipse.core.runtime.adaptor.EclipseStarter.run（EclipseStarter.java:181） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57）在 sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:606）at org.eclipse.equinox.launcher.Main.invokeFramework（Main.java:636）at at org.eclipse.equinox.launcher.Main.basicRun（Main.java:591）at at org.eclipse.equinox.launcher.Main.run（Main.java:1450）at org.eclipse.equinox.launcher.Main.main（Main.java:1426）

Answer 1

您在互联网上找到的代码不完整。新建，导入和导出向导实现IWorkbenchWizard并要求在显示向导之前调用init方法：

public void init(IWorkbench workbench, IStructuredSelection selection)

NullPointerException是因为尚未设置选择。

因此，在创建向导之后，在传递给WizardDialog之前，您需要执行以下操作：

if (wizard instanceof IWorkbenchWizard) {
   ((IWorkbenchWizard)wizard).init(workbench, selection);
}

其中selection是当前选择或StructuredSelection.EMPTY，但不是空。

Eclipse WST打开新的XML向导会抛出java.lang.NullPointerException

1 个答案: