I'm pretty new to using FXML as a source for JavaFX. Not sure what I did wrong. The Fields are apparently null, but if I'd try to initialize them wouldn't they be using a different object than the ones from the FXML file?
Simple layout:
The Controller class just contains this code. I'm just testing and trying to add items to the ListView but apparently the auctionListView is null and not pointing to anything. Same goes for gridPane when I try to use it.
Controller class:
public class Controller {
@FXML
private GridPane gridPane;
@FXML
private ListView<String> auctionListView;
public void init() {
ObservableList<String> ol = FXCollections.observableArrayList("Hi",
"Hello", "Hellooo");
if (auctionListView == null)
System.out.println("Null.");
auctionListView.setItems(ol); // <-----Error occurs at this line.
}
}
Nothing too much to say for the Main class, just the usual simple startup for a regular JavaFX application
Main:
public static void main(String[] args){
launch(args); //This launches the JavaFX GUI.
}
@Override
public void start(Stage primaryStage) throws Exception {
Controller controller = new Controller();
Parent fxml = FXMLLoader.load(Main.class.getClassLoader().getResource("scene.fxml"));
Scene scene = new Scene(fxml);
primaryStage.setScene(scene);
primaryStage.setResizable(false);
primaryStage.setTitle("Interest Viewer");
primaryStage.show();
controller.init();
}
scene.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.effect.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.media.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.shape.*?>
<?import javafx.scene.image.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<AnchorPane prefHeight="600.0" prefWidth="800.0" stylesheets="@style.css" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Controller">
<children>
<BorderPane prefHeight="600.0" prefWidth="800.0">
<left>
<VBox prefHeight="600.0" prefWidth="205.0" BorderPane.alignment="CENTER">
<children>
<ListView fx:id="auctionListView" fixedCellSize="50.0" nodeOrientation="LEFT_TO_RIGHT" stylesheets="@list.css" VBox.vgrow="ALWAYS">
<VBox.margin>
<Insets />
</VBox.margin>
<padding>
<Insets bottom="5.0" left="5.0" right="5.0" top="5.0" />
</padding>
</ListView>
</children>
</VBox>
</left>
<center>
<GridPane fx:id="gridPane" BorderPane.alignment="CENTER">
<columnConstraints>
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
</columnConstraints>
<rowConstraints>
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
</rowConstraints>
<children>
<Button mnemonicParsing="false" text="Button" />
</children>
</GridPane>
</center>
</BorderPane>
</children>
</AnchorPane>
Note the "Null." as that was printed out from the simple null check for the auctionListView in the Controller class.
Output/Error:
Null.
Exception in Application start method
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:498)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
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:498)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$154(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at Controller.init(Controller.java:19)
at Main.start(Main.java:26)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
... 1 more
Exception running application Main
