Loader-Instanziierung löst Nullzeiger in JavaFX aus
Ich habe zwei fxml-Dateien und einen Controller für jede deklariert: rootlayoutcontroller ist ein Controller für rootlayout.fxml und overviewcontroller ist ein Controller für overview.fxml
rootlayout verfügt über eine Menüleiste mit geöffnetem Element "Datei", und der Übersichtscontroller verfügt über eine Schaltfläche "Zeichnen".
Ich habe eine andere Klasse namens DataStructure. Ich möchte eine Datei öffnen und den Pfad an overviewcontroller senden. Wenn ich dann auf Zeichnen klicke, wird der Konstruktor von DartaStructure mit dem Pfad als Parameter instanziiert. Aber sobald ich auf Öffnen klicke, wirft das Programm im Dialogfeld zum Öffnen der Dateiauswahl einen Nullzeiger für inhandleOpen() Methode. Manchmal bekomme ich Quelle nicht gefunden!
In einer Hauptklasse packe ich die Übersicht in Rootlayout und zeige die Bühne.
RootLayoutController:
public class RootLayoutController {
private final Model model;
public RootLayoutController(Model model){
this.model = model;
}
/**
* Opens a FileChooser to let the user select a .z3lgm file to load.
*/
@FXML
private void handleOpen() {
FileChooser fileChooser = new FileChooser();
// Set extension filter
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter(
"3lgm2 files (*.z3lgm)", "*z3lgm");
fileChooser.getExtensionFilters().add(extFilter);
// Show open file dialog
File file = fileChooser.showOpenDialog(main.getPrimaryStage());
if (file != null) {
path = file.toString();
model.setText(path);//error
}
}
}
OverViewController:
public class OverViewController implements Initializable {
private final Model model;
public OverViewController(Model model){
this.model = model;
}
public void treeTableDraw(ActionEvent event) {
String p = model.getText();
new Controller(p);
drawTable();
numberOfFunctions = dc.getFuncAll().size();
numberOfOrganizations = dc.getSortedAssignedOrg().size();
funcLabel.setText(numberOfFunctions + "");
orgLabel.setText(numberOfOrganizations + "");
btnDraw.setDisable(true);
}
}
Error Stack:
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1770)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1653)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.doSelect(ContextMenuContent.java:1405)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.lambda$createChildren$341(ContextMenuContent.java:1358)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer$Lambda$326/15872584.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3758)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3486)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2495)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:350)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandle,r.java:275)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$350(GlassViewEventHandler.java:385)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$Lambda$209/5704663.get(Unknown Source)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:404)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:384)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:927)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.lambda$null$48(GtkApplication.java:139)
at com.sun.glass.ui.gtk.GtkApplication$Lambda$41/19140780.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1767)
... 46 more
Caused by: java.lang.NullPointerException
at view.RootLayoutController.handleOpen(RootLayoutController.java:174)
... 56 more
Hauptklasse
public class Main extends Application {
private Stage primaryStage;
private BorderPane rootLayout;
private Model model = new Model;
// private ObservableList<DataConstructor> treeTableData =
// FXCollections.observableArrayList();
@Override
public void start(Stage primaryStage) {
this.primaryStage = primaryStage;
this.primaryStage.setTitle("IT-Saturation");
initRootLayout();
showOverView();
}
private void showOverView() {
try {
FXMLLoader loader = new FXMLLoader();
loader.setLocation(Main.class.getResource("/view/OverView.fxml"));
loader.setController(new OverViewController(model));
// Parent firstUI = loader.load();
AnchorPane overView = (AnchorPane) loader.load();
rootLayout.setCenter(overView);
// OverViewController controller = loader.getController();
// controller.setMainApp(this);
} catch (IOException e) {
e.printStackTrace();
}
}
private void initRootLayout() {
try {
FXMLLoader loader = new FXMLLoader();
loader.setLocation(Main.class.getResource("/view/RootLayout.fxml"));
loader.setController(new RootLayoutController(model));
rootLayout = (BorderPane) loader.load();
// show scene containing the root layout
Scene scene = new Scene(rootLayout);
scene.getStylesheets().add(
getClass().getResource("application.css").toExternalForm());
primaryStage.setScene(scene);
// gives controller access to main
RootLayoutController controller = loader.getController();
controller.setMainApp(this);
primaryStage.show();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Returns the main stage.
*
* @return primaryStage
*/
public Stage getPrimaryStage() {
return primaryStage;
}
public static void main(String[] args) {
launch(args);
}
public void showMostComputerizedStatistics() {
try {
// Load the fxml file and create a new stage for the popup.
FXMLLoader loader = new FXMLLoader();
loader.setLocation(Main.class
.getResource("view/BirthdayStatistics.fxml"));
AnchorPane page = (AnchorPane) loader.load();
Stage dialogStage = new Stage();
dialogStage.setTitle("Birthday Statistics");
dialogStage.initModality(Modality.WINDOW_MODAL);
dialogStage.initOwner(primaryStage);
Scene scene = new Scene(page);
dialogStage.setScene(scene);
// Set the persons into the controller.
MostComputerizedController controller = loader.getController();
dialogStage.show();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Das ist RootLayout fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.input.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.BorderPane?>
<BorderPane prefHeight="500.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" >
<top>
<MenuBar BorderPane.alignment="CENTER">
<menus>
<Menu text="_File">
<items>
<MenuItem onAction="#handleOpen" text="_Open" />
<MenuItem mnemonicParsing="false" onAction="#handleExportPic" text="Export as picture" />
<MenuItem mnemonicParsing="false" text=" Save as" />
<MenuItem mnemonicParsing="false" onAction="#doPrint" text="Print" />
<MenuItem onAction="#handleExit" text="E_xit">
<accelerator>
<KeyCodeCombination alt="UP" code="X" control="DOWN" meta="UP" shift="UP" shortcut="UP" />
</accelerator></MenuItem>
</items>
</Menu>
<Menu mnemonicParsing="false" onAction="#handleMostComputerizedStatistics" text="Statistics">
<items>
<MenuItem mnemonicParsing="false" onAction="#handleMostComputerizedStatistics" text="Show Statistics" />
</items>
</Menu>
<Menu mnemonicParsing="false" text="Help">
<items>
<MenuItem mnemonicParsing="false" text="About" />
</items>
</Menu>
</menus>
</MenuBar>
</top>
</BorderPane>Und das ist Übersicht fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.text.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" >
<children>
<SplitPane dividerPositions="0.2391304347826087" layoutX="62.0" layoutY="52.0" prefHeight="400.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<items>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0" SplitPane.resizableWithParent="false">
<children>
<Button fx:id="btnDraw" layoutX="24.0" layoutY="297.0" mnemonicParsing="false" onAction="#treeTableDraw" text="Draw" AnchorPane.leftAnchor="22.0" AnchorPane.rightAnchor="36.0" />
<Label fx:id="funcLabel" layoutX="24.0" layoutY="155.0" opacity="0.72" prefHeight="15.0" prefWidth="38.0" text="0" AnchorPane.bottomAnchor="190.0" AnchorPane.leftAnchor="24.0" AnchorPane.rightAnchor="77.0">
<font>
<Font size="10.0" />
</font></Label>
<Label fx:id="orgLabel" layoutX="17.0" layoutY="219.0" opacity="0.72" prefHeight="14.0" prefWidth="38.0" text="0" AnchorPane.bottomAnchor="165.0" AnchorPane.leftAnchor="24.0" AnchorPane.rightAnchor="84.0" AnchorPane.topAnchor="219.0">
<font>
<Font size="10.0" />
</font></Label>
<Label layoutX="63.0" layoutY="155.0" text="Functions" AnchorPane.bottomAnchor="190.0">
<font>
<Font size="11.0" />
</font>
</Label>
<Label layoutX="56.0" layoutY="219.0" text="Organizations" AnchorPane.bottomAnchor="165.0" AnchorPane.topAnchor="213.0">
<font>
<Font size="10.0" />
</font>
</Label>
<Button fx:id="btnReset" layoutX="21.0" layoutY="345.0" mnemonicParsing="false" onAction="#treeTableReset" onKeyPressed="#treeTableReset" prefHeight="25.0" prefWidth="81.0" text="Reset" AnchorPane.leftAnchor="22.0" AnchorPane.rightAnchor="36.0" />
</children></AnchorPane>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0" SplitPane.resizableWithParent="false">
<children>
<ScrollPane fx:id="scrollPane" prefHeight="398.0" prefWidth="480.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<content>
<TreeTableView fx:id="treeTable" editable="true" prefHeight="375.0" prefWidth="246.0" />
</content>
</ScrollPane>
</children></AnchorPane>
</items>
</SplitPane>
</children>
</AnchorPane>