JavaFX Anwendung startet nicht, kann den Fehler nicht finden (Exception in Application start method)

[beli3ver]

Hallo,

ich fange gerade an Gradle in Verbindung mit JavaFX kennenzulernen.
Habe dazu folgendes kleines Snippet:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.Parent;
import javafx.stage.Stage;
import javafx.fxml.FXMLLoader;
import java.io.IOException;

public class HelloFX extends Application {

    @Override
    public void start(Stage stage) {
        try {
            Parent root = FXMLLoader.load(getClass().getResource("@ui/login.fxml"));

            Scene scene = new Scene(root, 300, 275);

            stage.setTitle("FXML Welcome");
            stage.setScene(scene);
            stage.show();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        launch();
    }

}

Dazu habe ich folgende build.gradle

plugins {
  id 'application'
  id 'org.openjfx.javafxplugin' version '0.0.8'
}

repositories {
    mavenCentral()
}

javafx {
    version = "15.0.1"
    modules = [ 'javafx.controls', 'javafx.fxml' ]
}

mainClassName = 'HelloFX'

Meine Ordner Struktur sieht wie folgt aus:

Wenn ich das jetzt ausführe, bekomme ich die folgende Meldung:

~/Entwicklung/stingle via ☕ v15.0.2 ❯ ./gradlew run

> Task :run FAILED
Exception in Application start method
java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:564)
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:564)
        at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1071)
Caused by: java.lang.RuntimeException: Exception in Application start method
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
        at java.base/java.lang.Thread.run(Thread.java:832)
Caused by: java.lang.NullPointerException: Location is required.
        at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3316)
        at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3280)
        at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3249)
        at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3222)
        at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3199)
        at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3192)
        at HelloFX.start(HelloFX.java:13)
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
        at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
        at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
        at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
        at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
Exception running application HelloFX

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':run'.
> Process 'command '/Users/maltekiefer/Library/Java/JavaVirtualMachines/openjdk-15.0.2/Contents/Home/bin/java'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
3 actionable tasks: 2 executed, 1 up-to-date

 

[kneitzel]

Bei der Angab der Ressource in:

Parent root = FXMLLoader.load(getClass().getResource("@ui/login.fxml"));

Was erwartest Du von dem @ Symbol? Das kann direkt weg und dann sollte er es auch finden.

Und am Besten packst Du es in src/main/resources und gibt immer den absoluten Pfad an - also ein /ui/login.fxml so Du es in den Ordner ui in resources packst.