JavaFX:java.lang.IllegalAccessError: class com.sun.javafx.fxml.FXMLLoaderHelper

1. 环境

JDK：11

Openjfx：13

IDE：IDEA

Maven：3.0

2. 问题描述

直接在入口函数中加载FXML，运行报错

代码：

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.stage.Stage;

import java.io.IOException;

public class Main4 extends Application {

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

    @Override
    public void start(Stage primaryStage) throws IOException {
        primaryStage.setTitle("测试一个按钮");
        Parent root = FXMLLoader.load(getClass().getResource("TestUI.fxml"));
        primaryStage.show();
    }
}

错误提示：

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$2(LauncherImpl.java:195)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.IllegalAccessError: class com.sun.javafx.fxml.FXMLLoaderHelper (in unnamed module @0x4270ead7) cannot access class com.sun.javafx.util.Utils (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.util to unnamed module @0x4270ead7
	at com.sun.javafx.fxml.FXMLLoaderHelper.(FXMLLoaderHelper.java:38)
	at javafx.fxml.FXMLLoader.(FXMLLoader.java:2056)
	at Main4.start(Main4.java:18)
	at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$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 Main4

3. 解决方案

方案一：

在Main函数中使用

public static void main(String[] args) {
        Application.launch(App.class, args);
    }

然后再创建一个App类，继承Application

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

import java.io.IOException;

public class App extends Application {

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

    @Override
    public void start(Stage primaryStage) throws IOException {
        primaryStage.setTitle("测试一个按钮");
        Parent root = FXMLLoader.load(getClass().getResource("TestUI.fxml"));
        Scene scene = new Scene(root, 800, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

这样改造之后即可正常启动运行。

 

方案二(网络上的解决方案，没试过)：

https://stackoverflow.com/questions/52467561/intellij-cant-recognize-javafx-11-with-openjdk-11

添加模块

--module-path="C:\Program Files\Java\javafx-sdk-11\lib" \
--add-modules=javafx.controls,javafx.fxml