JavaFX 使用label时出现异常 class

Question

The classes I have used so far in the codeblock all work. As soon as I try to use Label, even if I dont add it to the Scene I get the following errors. I use Intellij, I was thinking that the classes I use are already available in Intellij and Label is not one of the included, and that's why I get the error.

I have downloaded JavaFX 13 and the folder is on my desktop, in the Project settings - Libraries the path for JavaFX goes to Desktop/javafx-sdk-13.0.2/lib

Code

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.GridPane;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class CompoundInterest extends Application {

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

    @Override
    public void start(Stage primaryStage) {
//        Group root = new Group();
        GridPane pane = new GridPane();
        pane.setAlignment(Pos.CENTER);
        pane.setPadding(new Insets(5,5,5,5));
        pane.setHgap(5.5);
        pane.setVgap(5.5);

        Label label = new Label();
        Text text1 = new Text("Test");
        pane.add(text1,1,1);
//        pane.add(new Label("Username"), 0, 0);

        Scene scene = new Scene(pane, 400, 400);
        primaryStage.setResizable(false);
        primaryStage.setTitle("Test");
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

Error message:

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:567)
    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:567)
    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$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:830)
Caused by: java.lang.IllegalAccessError: superclass access check failed: class com.sun.javafx.scene.control.ControlHelper (in unnamed module @0x20a25f19) cannot access class com.sun.javafx.scene.layout.RegionHelper (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.scene.layout to unnamed module @0x20a25f19
    at java.base/java.lang.ClassLoader.defineClass1(Native Method)
    at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016)
    at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151)
    at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:821)
    at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:719)
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:642)
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:600)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    at javafx.scene.control.Control.<clinit>(Control.java:86)
    at assignment_2.exercise7.CompoundInterest.start(CompoundInterest.java:28)
    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)
    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 assignment_2.exercise7.CompoundInterest

Process finished with exit code 1

Answer 1

In Intellij Run -> Edit configurations Set module path to "--module-path "pathToJavaFx\javafx-sdk-13.0.2\lib" --add-modules javafx.controls,javafx.fxml"

Is explained here https://openjfx.io/openjfx-docs/

Answer 2

Maven

As the Getting Started page explains, you have a choice in how to build your JavaFX projects.

JavaFX 13 builds on top of JDK 13 and is a standalone component. There are 2 different options for developing JavaFX applications:

• Use the JavaFX SDK

• Use a build system (eg maven/gradle) to download the required modules from Maven Central.

The other Answer seems to address the first. You may instead choose to make you project driven by a tool such as Maven .

While learning a bit about Maven may seem like an annoying diversion, I have found it to be worth the time and effort, saving time with configuration and building of my projects. And Maven-driven projects are portable between the major IDE s.

For instructions on using configuring your Maven POM file for OpenJFX work, see Run HelloWorld using Maven .

As shown on that documentation page, this XML element in your Maven POM will result in the necessary JavaFX classes, including Label , being automatically downloaded for use within your app.

<dependency>
    <groupId>org.openjfx</groupId>
    <artifactId>javafx-controls</artifactId>
    <version>13</version>
</dependency>