Cannot run JavaFX application jar

Question

Problem:

• Running JavaFX application jar fails though the main javafx.application.Application class runs successfully showing a GUI window.

What I have:

• IntelliJ IDEA Community Edition 2021.2.1
• Liberica Full JDK 11.0.12+7 x86 64 bit for Windows(Already includes JavaFX)
• Windows 10 Home 64bit

Project structure(IDE generated, not modified):

    main
        ├───java
        │   │   module-info.java
        │   │
        │   ├───com
        │   │   └───tejasb
        │   │       └───test
        │   │               HelloApplication.java
        │   │               HelloController.java
        │   │
        │   └───META-INF
        │           MANIFEST.MF
        │
        └───resources
            └───com
                └───tejasb
                    └───test
                            hello-view.fxml

Source code:

• HelloApplication.java

    package com.tejasb.test;
    
    import javafx.application.Application;
    import javafx.fxml.FXMLLoader;
    import javafx.scene.Scene;
    import javafx.stage.Stage;
    
    import java.io.IOException;
    
    public class HelloApplication extends Application {
        @Override
        public void start(Stage stage) throws IOException {
            FXMLLoader fxmlLoader = new FXMLLoader(HelloApplication.class.getResource("hello-view.fxml"));
            Scene scene = new Scene(fxmlLoader.load(), 320, 240);
            stage.setTitle("Hello!");
            stage.setScene(scene);
            stage.show();
        }
    
        public static void main(String[] args) {
            launch();
        }
    }

• HelloController.java

    package com.tejasb.test;
    
    import javafx.fxml.FXML;
    import javafx.scene.control.Label;
    
    public class HelloController {
        @FXML
        private Label welcomeText;
    
        @FXML
        protected void onHelloButtonClick() {
            welcomeText.setText("Welcome to JavaFX Application!");
        }
    }

• hello-view.fxml

    <?xml version="1.0" encoding="UTF-8"?>
    
    <?import javafx.geometry.Insets?>
    <?import javafx.scene.control.Label?>
    <?import javafx.scene.layout.VBox?>
    
    <?import javafx.scene.control.Button?>
    <VBox alignment="CENTER" spacing="20.0" xmlns:fx="http://javafx.com/fxml"
          fx:controller="com.tejasb.test.HelloController">
        <padding>
            <Insets bottom="20.0" left="20.0" right="20.0" top="20.0"/>
        </padding>
    
        <Label fx:id="welcomeText"/>
        <Button text="Hello!" onAction="#onHelloButtonClick"/>
    </VBox>

• module-info.java

    module com.tejasb.test {
        requires javafx.controls;
        requires javafx.fxml;
    
    
        opens com.tejasb.test to javafx.fxml;
        exports com.tejasb.test;
    }

• MANIFEST.MF

    Manifest-Version: 1.0
    Main-Class: com.tejasb.test.HelloApplication

Exception stack trace(when application jar is ran):

    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:62)
            at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
            at java.base/java.lang.reflect.Method.invoke(Method.java:566)
            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:62)
            at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
            at java.base/java.lang.reflect.Method.invoke(Method.java:566)
            at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1051)
    Caused by: java.lang.RuntimeException: Exception in Application start method
            at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
            at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
            at java.base/java.lang.Thread.run(Thread.java:829)
    Caused by: java.lang.IllegalStateException: Location is not set.
            at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2459)
            at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:2435)
            at com.tejasb.test.HelloApplication.start(HelloApplication.java:14)
            at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$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$10(PlatformImpl.java:428)
            at java.base/java.security.AccessController.doPrivileged(Native Method)
            at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
            at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
            at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
            at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
            ... 1 more
    Exception running application com.tejasb.test.HelloApplication

Content of application jar:

    Test.jar
    │   module-info.class
    │
    ├───com
    │   └───tejasb
    │       └───test
    │               HelloApplication.class
    │               HelloController.class
    │
    ├───META-INF
    │       MANIFEST.MF
    │
    └───resources
        └───com
            └───tejasb
                └───test
                        hello-view.fxml

Steps to reproduce problem:

1. Create project in IntelliJ IDEA with project structure as above
2. Create new run configuration as Application
   • Set Name, JDK/JRE, -cp from drop down menu and main class as com.tejasb.test.HelloApplication
3. Go to Project structure>Project settings>Artifacts
   • Click + then JAR>From modules with dependencies...
   • Set Main class as com.tejasb.test.HelloApplication and select copy to the output directory and link via manifest
   • Click OK then on the right side
   • Right click .jar and select Create directory and set name as resources
   • Then right click created directory and select Add copy of>Directory content and select src>main>resources directory (from project)
   • Click OK
4. Click Run button(application should run successfully showing a window with a button in it)
5. Now, click Build>Build artifacts...>build(this should build na application jar file at your specified location)
6. Finally, when this generated jar is ran from console, it doesn't work, throws above exception.

What I have tried:

• Setting this

    FXMLLoader fxmlLoader = new FXMLLoader(HelloApplication.class.getResource("hello-view.fxml"));

to this

    FXMLLoader fxmlLoader = new FXMLLoader(HelloApplication.class.getResource("/hello-view.fxml"));

this throws the same exception as above even in step 4(Of Steps to reproduce problem) and step 5(Of Steps to reproduce problem) is as it was.

• Also, tried to use HelloApplication.class.getClassLoader().getResource("hello-view.fxml") and HelloApplication.class.getClassLoader().getResource("/hello-view.fxml") and what not.... But, the jar throws the same exception.

Any help on this will be appreciated. Thanks

Answer 1

An impressive amount of work went into creating this question.

Your problem is that there should not be a directory called resources in your jar.

Instead, hello-view.fxml should end up in the same location in the jar as HelloApplication.

You don’t need a / in the resource lookup.

I don’t know how to fix your resource packaging with your current build method.

I’d recommend using a build tool such as Maven instead of the IDEs built-in artifact creation. I think there might be tutorials for that at openjfx.io. With your current directory structure Maven would automatically place all output files in the correct location of the artifact jar.

---

If you really did want to keep a folder called resources in your jar (which would be highly unusual and not recommended), then you could just leave it as is and lookup your fxml using the path /resources/com/tejasb/test/hello-view.fxml. Note the asker replied in comments that this method did not work.