将数据添加到TableViewer时出现java异常

1 年，3 月 Questions & Answers 648

我在一个组合中有两个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，我想通过关联菜单将某些对象从viewer1更改为viewer2，第一次添加成功，但下一次将对象填充到viewer2时，我总是会遇到以下异常： java。lang.UnsupportedOperationException

如果viewer2预先包含一些对象，则不会发生这种情况，只有当viewer2为空时才会发生这种情况。这是我将一些数据从viewer1添加到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;

它第一次在IF条件下工作得很好，但是下一次当viewer2包含一些数据时，我总是在上面的错误行中得到异常。 @Krumelur，我补充了我得到的stacktrace：

!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)

请帮帮我。非常感谢你的回答

共 (3) 个答案

# 1 楼答案
我找到了一个解决方法，将viewer2初始化输入的方式更改如下：
```
viewer2.setInput(new ArrayList<MyObject>())
```
在我为输入设置NUll之前，无法使用addAll（）方法向tableviewer添加更多对象。谢谢大家的帮助。致以最良好的祝愿
# 2 楼答案

并非所有java.util.List接口的实现都支持addAll()方法。例如，由^{}返回的方法不会返回，这是由^{}使用的方法
# 3 楼答案

这听起来像是从您的内容提供商引发的异常。您是否检查过您的内容提供商是否确实接受该列表？您使用什么内容提供商

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将数据添加到TableViewer时出现java异常

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