通过TableView更新值时的ClassCast异常

时间：2018-10-21 21:45:56

标签： java javafx gtfs

上下文：使用Google Transit GTFS API进行实验。使用表格视图显示路线数据，我想使数据在表格中可编辑。当该属性为String（路由ID和路由长名称）时，我已经成功完成了此操作，但是使单元格可编辑的代码将对非String属性抛出错误。

表格代码：

table = new TableView<>();
    ObservableList data = FXCollections.observableList(routes);
    table.setItems(data);
    table.setEditable(true);

颜色数据列的代码：

TableColumn routeColorCol = new TableColumn("Route Color");
    routeColorCol.setCellValueFactory(new PropertyValueFactory("route_color"));
    routeColorCol.setCellFactory(TextFieldTableCell.forTableColumn());
    routeColorCol.setOnEditCommit(new EventHandler<TableColumn.CellEditEvent>() {
        @Override
        public void handle(TableColumn.CellEditEvent t){
            ((Route) t.getTableView().getItems().get(
                    t.getTablePosition().getRow())
            ).setRoute_color((Color)t.getNewValue());
        }
    });

我将表添加到Vbox和选项卡窗格中。我得到的stacktrace没有指向我的代码的任何地方，所以我很茫然。

Stacktrace：

Oct 21, 2018 4:39:37 PM javafx.fxml.FXMLLoader$ValueElement processValue
WARNING: Loading FXML document with JavaFX API of version 9.0.1 by JavaFX runtime of version 8.0.141
Exception in thread "JavaFX Application Thread" java.lang.ClassCastException: javafx.scene.paint.Color cannot be cast to java.lang.String
at javafx.util.converter.DefaultStringConverter.toString(DefaultStringConverter.java:34)
at javafx.scene.control.cell.CellUtils.getItemText(CellUtils.java:100)
at javafx.scene.control.cell.CellUtils.updateItem(CellUtils.java:201)
at javafx.scene.control.cell.TextFieldTableCell.updateItem(TextFieldTableCell.java:204)
at javafx.scene.control.TableCell.updateItem(TableCell.java:663)
at javafx.scene.control.TableCell.indexChanged(TableCell.java:468)
at javafx.scene.control.IndexedCell.updateIndex(IndexedCell.java:116)
at com.sun.javafx.scene.control.skin.TableViewSkin.resizeColumnToFitContent(TableViewSkin.java:241)
at com.sun.javafx.scene.control.skin.TableViewSkin.resizeColumnToFitContent(TableViewSkin.java:54)
at com.sun.javafx.scene.control.skin.TableColumnHeader.doColumnAutoSize(TableColumnHeader.java:531)
at com.sun.javafx.scene.control.skin.TableColumnHeader.updateScene(TableColumnHeader.java:474)
at com.sun.javafx.scene.control.skin.TableColumnHeader.handlePropertyChanged(TableColumnHeader.java:314)
at com.sun.javafx.scene.control.skin.TableColumnHeader.lambda$new$49(TableColumnHeader.java:149)
at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55)
at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:182)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ReadOnlyObjectPropertyBase.fireValueChangedEvent(ReadOnlyObjectPropertyBase.java:74)
at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:102)
at javafx.scene.Node$ReadOnlyObjectWrapperManualFire.fireSuperValueChangedEvent(Node.java:831)
at javafx.scene.Node.invalidatedScenes(Node.java:883)
at javafx.scene.Node.setScenes(Node.java:921)
at javafx.scene.Parent$1.onChanged(Parent.java:269)
at com.sun.javafx.collections.TrackableObservableList.lambda$new$29(TrackableObservableList.java:45)
at com.sun.javafx.collections.ListListenerHelper$Generic.fireValueChangedEvent(ListListenerHelper.java:329)
at com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73)
at javafx.collections.ObservableListBase.fireChange(ObservableListBase.java:233)
at javafx.collections.ListChangeBuilder.commit(ListChangeBuilder.java:482)
at javafx.collections.ListChangeBuilder.endChange(ListChangeBuilder.java:541)
at javafx.collections.ObservableListBase.endChange(ObservableListBase.java:205)
at javafx.collections.ModifiableObservableListBase.setAll(ModifiableObservableListBase.java:90)
at com.sun.javafx.collections.VetoableListDecorator.setAll(VetoableListDecorator.java:116)
at com.sun.javafx.scene.control.skin.NestedTableColumnHeader.updateContent(NestedTableColumnHeader.java:487)
at com.sun.javafx.scene.control.skin.NestedTableColumnHeader.updateTableColumnHeaders(NestedTableColumnHeader.java:317)
at com.sun.javafx.scene.control.skin.NestedTableColumnHeader.checkState(NestedTableColumnHeader.java:544)
at com.sun.javafx.scene.control.skin.NestedTableColumnHeader.computePrefHeight(NestedTableColumnHeader.java:427)
at javafx.scene.Parent.prefHeight(Parent.java:929)
at javafx.scene.layout.Region.prefHeight(Region.java:1435)
at com.sun.javafx.scene.control.skin.TableHeaderRow.computePrefHeight(TableHeaderRow.java:331)
at com.sun.javafx.scene.control.skin.TableHeaderRow.computeMinHeight(TableHeaderRow.java:324)
at javafx.scene.Parent.minHeight(Parent.java:957)
at javafx.scene.layout.Region.minHeight(Region.java:1401)
at javafx.scene.control.SkinBase.computeMinHeight(SkinBase.java:254)
at javafx.scene.control.Control.computeMinHeight(Control.java:489)
at javafx.scene.Parent.minHeight(Parent.java:957)
at javafx.scene.layout.Region.minHeight(Region.java:1401)
at javafx.scene.layout.Region.computeChildMinAreaHeight(Region.java:1697)
at javafx.scene.layout.VBox.getAreaHeights(VBox.java:436)
at javafx.scene.layout.VBox.computeContentHeight(VBox.java:518)
at javafx.scene.layout.VBox.computeMinHeight(VBox.java:396)
at javafx.scene.Parent.minHeight(Parent.java:957)
at javafx.scene.layout.Region.minHeight(Region.java:1401)
at javafx.scene.layout.Region.computeChildPrefAreaHeight(Region.java:1762)
at javafx.scene.layout.AnchorPane.computeHeight(AnchorPane.java:297)
at javafx.scene.layout.AnchorPane.computeMinHeight(AnchorPane.java:246)
at javafx.scene.Parent.minHeight(Parent.java:957)
at javafx.scene.layout.Region.minHeight(Region.java:1401)
at javafx.scene.layout.Region.boundedNodeSizeWithBias(Region.java:1917)
at javafx.scene.layout.Region.layoutInArea(Region.java:2323)
at javafx.scene.layout.Region.layoutInArea(Region.java:2238)
at javafx.scene.layout.Region.layoutInArea(Region.java:2179)
at javafx.scene.layout.StackPane.layoutChildren(StackPane.java:342)
at javafx.scene.Parent.layout(Parent.java:1087)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Scene.doLayoutPass(Scene.java:552)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2397)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$30(Toolkit.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:354)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:381)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:510)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:490)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$404(QuantumToolkit.java:319)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:748)
Exception in thread "JavaFX Application Thread" java.lang.ClassCastException: javafx.scene.paint.Color cannot be cast to java.lang.String
at javafx.util.converter.DefaultStringConverter.toString(DefaultStringConverter.java:34)
at javafx.scene.control.cell.CellUtils.getItemText(CellUtils.java:100)
at javafx.scene.control.cell.CellUtils.updateItem(CellUtils.java:201)
at javafx.scene.control.cell.TextFieldTableCell.updateItem(TextFieldTableCell.java:204)
at javafx.scene.control.TableCell.updateItem(TableCell.java:663)
at javafx.scene.control.TableCell.indexChanged(TableCell.java:468)
at javafx.scene.control.IndexedCell.updateIndex(IndexedCell.java:116)
at com.sun.javafx.scene.control.skin.TableRowSkinBase.updateCells(TableRowSkinBase.java:533)
at com.sun.javafx.scene.control.skin.TableRowSkinBase.init(TableRowSkinBase.java:147)
at com.sun.javafx.scene.control.skin.TableRowSkin.<init>(TableRowSkin.java:64)
at javafx.scene.control.TableRow.createDefaultSkin(TableRow.java:212)
at javafx.scene.control.Control.impl_processCSS(Control.java:872)
at javafx.scene.Node.processCSS(Node.java:9058)
at javafx.scene.Node.applyCss(Node.java:9155)
at com.sun.javafx.scene.control.skin.VirtualFlow.setCellIndex(VirtualFlow.java:1964)
at com.sun.javafx.scene.control.skin.VirtualFlow.getCell(VirtualFlow.java:1797)
at com.sun.javafx.scene.control.skin.VirtualFlow.getCellLength(VirtualFlow.java:1879)
at com.sun.javafx.scene.control.skin.VirtualFlow.computeViewportOffset(VirtualFlow.java:2528)
at com.sun.javafx.scene.control.skin.VirtualFlow.layoutChildren(VirtualFlow.java:1189)
at javafx.scene.Parent.layout(Parent.java:1087)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Parent.layout(Parent.java:1093)
at javafx.scene.Scene.doLayoutPass(Scene.java:552)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2397)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$30(Toolkit.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:354)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:381)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:510)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:490)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$404(QuantumToolkit.java:319)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:748)

1 个答案:

答案 0 :(得分：1)

您使用了原始类型，因此可以进行编译，但是在运行时发生类型不一致。您的routeColorCol应该显示javafx.scene.paint.Color的值，但是您的单元格工厂回调被编写为读取String的值-这就是在运行时导致ClassCastException的原因。

来自TextFieldTableCell.forTableColumn()：

  

提供一个TextField，当   双击单元格，或者当TableView.edit（int，   javafx.scene.control.TableColumn）被调用。 仅此方法   可处理类型为String 的TableColumn实例。

您应该使用重载方法TextFieldTableCell.forTableColumn(StringConverter)。

routeColorCol.setCellFactory(
    TextFieldTableCell.<Foo, Color> forTableColumn(new StringConverter<Color>() {
        @Override
        public String toString(Color object) {
            return object != null ? object.toString() : "";
        }

        @Override
        public Color fromString(String string) {
            return Color.valueOf(string);
        }
    }
));
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