将数据添加到TableViewer时出现异常

Question

我在组合中有 2 个 TableViewer 控件（假设它们是：viewer1、viewer2）。初始化应用程序时，一个“viewer1”从服务器填充数据，而“viewer2”设置为空。

viewer1.setInput(getData());
viewer2.setInput(null);

现在我想通过上下文菜单将某些对象从viewer1更改为viewer2，第一次添加成功，但是下次当我将对象填充到viewer2时，我总是得到这个异常： java.lang.UnsupportedOperationException

如果 viewer2 预先包含一些对象，则不会发生这种情况，仅当 viewer2 为空时才会发生。 这是我添加将一些数据从 viewer1 移动到 viewer2 的方法：

//get selected objects in Viewer1
IStructuredSelection selection= (IStructuredSelection) viewer1.getSelection();
if(selection!=null){
            selectedList=(List<MyObject>)selection.toList();
            for(MyObject obj: selectedList){
                //do something here
            }
            //remove all
            ((List<MyObject>)viewer1().getInput()).removeAll(selectedList);
            viewer1.refresh();
        }
//viewer1 get above List
if((List<MyObject>)viewer2.getInput()==null)
 viewer2.setInput(selectedList);
else {
 ((List<MyObject>)viewer2.getInput()).addAll(selectedList);  //(Line Error)
}
viewer2.refresh;

第一次在 IF 条件下效果很好，但下次在 viewer2< /strong> 包含一些数据，我总是在上面的错误行得到异常。 @Krumelur，我添加了我得到的堆栈跟踪：

!ENTRY org.eclipse.ui 4 0 2011-12-27 16:26:50.660
!MESSAGE Unhandled event loop exception
!STACK 0
java.lang.UnsupportedOperationException
    at java.util.AbstractList.add(Unknown Source)
    at java.util.AbstractList.add(Unknown Source)
    at java.util.AbstractCollection.addAll(Unknown Source)
    at com.saltlux.om.client.customwidgets.NeutralSetWidget.getReviewFromOtherWidget(NeutralSetWidget.java:39)
    at com.saltlux.om.client.customwidgets.NeutralSetWidget$1.handleEvent(NeutralSetWidget.java:24)
    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.Widget.sendEvent(Widget.java:1077)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:774)
    at com.saltlux.om.client.customwidgets.PositiveSetWidget.add2TrainingSet(PositiveSetWidget.java:107)
    at com.saltlux.om.client.customwidgets.TrainingReviewWidget$10.run(TrainingReviewWidget.java:288)
    at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
    at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
    at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
    at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
    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 com.saltlux.om.client.Application.start(Application.java:21)
    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)

请帮助我。非常感谢您的任何答复！

Answer 1

并非所有 java.util.List 接口的实现都支持 addAll() 方法。例如， Arrays.asList() 不会，这是 StructuredSelection.toList()。

Answer 2

听起来您的内容提供商抛出了异常。您是否检查过您的内容提供商确实接受该列表？您使用什么内容提供商？

Answer 3

我找到了一个解决方法，更改了 viewer2 的初始化输入的方式，如下所示：

viewer2.setInput(new ArrayList<MyObject>())

在我为输入设置 NUll 之前，无法使用方法 addAll() 向 tableviewer 添加更多对象。
感谢大家的帮助。
此致！