JavaFX 11：创建标签时的IllegalAccessError

Question

这个问题很可能和这个问题有关，但是这个问题的提问者似乎没有提供足够的信息来得到有用的回答。

我正在尝试运行带有JDK和JavaFx SDK版本11.0.2的JavaFx应用程序。

这段代码完全按照预期工作,生成一个空窗口：

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class Main extends Application {

    public void start(Stage primaryStage) throws Exception {
        StackPane root = new StackPane();
        primaryStage.setScene(new Scene(root, 420, 420));
        primaryStage.show();
    }


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

但是，如果我尝试向stackpane添加标签，则会引发异常。

import ...
import javafx.scene.control.Label;

public class Main extends Application {

    public void start(Stage primaryStage) throws Exception {
        StackPane root = new StackPane();
        root.getChildren().add(new Label("42"));
        primaryStage.setScene(new Scene(root, 420, 420));
        primaryStage.show();
    }


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

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$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.IllegalAccessError: superclass access check failed: class com.sun.javafx.scene.control.ControlHelper (in unnamed module @0xbbd2743) cannot access class com.sun.javafx.scene.layout.RegionHelper (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.scene.layout to unnamed module @0xbbd2743
    at java.base/java.lang.ClassLoader.defineClass1(Native Method)
    at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016)
    at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)
    at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:802)
    at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:700)
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:623)
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
    at java.base/jdk.internal.loader.ClassLoaders$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 sample.Main.start(Main.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$10(PlatformImpl.java:428)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$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.gtk.GtkApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(GtkApplication.java:277)
    ... 1 more
Exception running application sample.Main

在IntelliJ Idea中，我相信我正确地选择了JDK，并且添加了/usr/lib/jvm/javafx-sdk-11.0.2/lib作为库。

IntelliJ Idea正在使用此命令启动应用程序（为了可读性将其拆分）：

/usr/lib/jvm/jdk-11.0.2/bin/java
  -Djava.library.path=/usr/lib/jvm/javafx-sdk-11.0.2/lib
  --add-modules javafx.base,javafx.graphics
  --add-reads javafx.base=ALL-UNNAMED
  --add-reads javafx.graphics=ALL-UNNAMED
  -javaagent:/opt/jetbrains/idea-IU-183.4886.37/lib/idea_rt.jar=36031:/opt/jetbrains/idea-IU-183.4886.37/bin
  -Dfile.encoding=UTF-8
  -classpath
    /home/rm/IdeaProjects/JfxPlayground/out/production/JfxPlayground
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/src.zip
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx-swt.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.web.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.base.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.fxml.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.media.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.swing.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.controls.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.graphics.jar
  -p
    /usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.base.jar
    :/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.graphics.jar
  sample.Main

我没有修改任何VM选项。

Answer 1

您已经对您的问题进行了解释：

我没有修改任何VM选项。

由于JavaFX11不再是JDK的一部分，您必须从这里使用JavaFX SDK（正如您正在做的那样），或者使用Maven/Gradle从Maven Central检索JavaFX模块。

• 使JavaFX模块可用于您的模块路径
• 定义要向项目中添加哪些模块

根据您的IntelliJ输出，它默认添加javafx.graphics和javafx.base:

--add-modules javafx.base,javafx.graphics

-p /usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.base.jar
:/usr/lib/jvm/javafx-sdk-11.0.2/lib/javafx.graphics.jar

（注意-p与--module-path)相同）

首先阅读https://openjfx.io/openjfx-docs/上的文档，包括IntelliJ文档，一节的非模块化项目用于您的IDE。并阅读第4部分。添加VM选项。

因此单击Run->Edit Configurations，并添加：

-p /usr/lib/jvm/javafx-sdk-11.0.2/lib --add-modules javafx.controls

申请并运行，问题就会解决。