Java 无法打开编辑器错误

我编写了一个简单的Eclipse插件，扩展名为.myfile。 当我运行它时，会收到以下错误消息：

无法打开编辑器：无法实例化编辑器类。这通常表示缺少无参数构造函数，或者编辑器的类名在plugin.xml中输入错误

My plugin.xml有以下声明：

<plugin>
    <extension point="org.eclipse.ui.editors">
        <editor     
            class="com.intel.editor.MyyEditor"
            extensions="myfile"
            icon="icons\sample.gif"
            id="com.intel.editor.MyyEditor"
            name="MyEditor">
        </editor>
    </extension>
</plugin> 

检查两件事：

在MyyEditor类中有一个默认构造函数。 日志中有错误吗？UI中的错误消息后是否有详细信息按钮？单击时是否显示堆栈跟踪？

java.lang.ClassNotFoundException: com.dal.editor.DalManifestEditor
  at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:513)
  at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:429)
  at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:417)
  at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
  at java.lang.ClassLoader.loadClass(Unknown Source)
  at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:345)
  at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:229)
  at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadClass(AbstractBundle.java:1207)
  at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:174)
  at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:905)
  at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
  at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
  at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:260)
  at org.eclipse.ui.internal.registry.EditorDescriptor.createEditor(EditorDescriptor.java:235)
  at org.eclipse.ui.internal.EditorManager.createPart(EditorManager.java:875)
  at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:609)
  at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:465)
  at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
  at org.eclipse.ui.internal.EditorReference.getEditor(EditorReference.java:289)
  at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2945)
  at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2850)
  at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2842)
  at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2793)
  at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
  at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2789)
  at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2773)
  at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2764)
  at org.eclipse.ui.ide.IDE.openEditor(IDE.java:651)
  at org.eclipse.ui.ide.IDE.openEditor(IDE.java:610)
  at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:355)
  at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:164)
  at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:249)
  at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:228)
  at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:275)
  at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:251)
  at org.eclipse.jdt.internal.ui.packageview.PackageExplorerActionGroup.handleOpen(PackageExplorerActionGroup.java:376)
  at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart$4.open(PackageExplorerPart.java:538)
  at org.eclipse.ui.OpenAndLinkWithEditorHelper$InternalListener.open(OpenAndLinkWithEditorHelper.java:48)
  at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:866)
  at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
  at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
  at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
  at org.eclipse.jface.viewers.StructuredViewer.fireOpen(StructuredViewer.java:864)
  at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:1152)
  at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1256)
  at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:275)
  at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:269)
  at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:309)
  at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
  at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
  at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
  at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
  at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
  at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
  at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
  at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
  at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
  at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
  at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
  at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
  at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
  at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
  at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
  at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
  at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
  at java.lang.reflect.Method.invoke(Unknown Source)
  at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
  at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
  at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
  at org.eclipse.equinox.launcher.Main.main(Main.java:1386)