JavaFX access internal webkit document

Question

I am trying to access javafx.web/com.sun.webkit.dom from my unnamed module javafx project. For this, I have created a class com.sun.webkit.dom.DomMapper. I do not see any error in the IDE, but when I run it using mvn clean javafx:run it complains -

Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: com/sun/webkit/dom/DomMapper
....
Caused by: java.lang.ClassNotFoundException: com.sun.webkit.dom.DomMapper
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
...

This is how my pom.xml looks

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId> ... </groupId>
    <artifactId> ... </artifactId>
    <version> ... </version>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <exec.mainClass> .... </exec.mainClass>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-fxml</artifactId>
            <version>11</version>
        </dependency> 
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-controls</artifactId>
            <version>11</version>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-graphics</artifactId>
            <version>11</version>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-web</artifactId>
            <version>11</version>
        </dependency>
        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.14.3</version>
        </dependency> 
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.openjfx</groupId>
                <artifactId>javafx-maven-plugin</artifactId>
                <version>0.0.4</version>
                <configuration>
                    <options>
                        <option>--add-exports</option><option>javafx.web/com.sun.webkit.dom=ALL-UNAMED</option>
                        <option>--add-opens</option><option>javafx.web/com.sun.webkit.dom=ALL-UNAMED</option>
                    </options>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <compilerArgs>
                        <arg>--add-exports</arg><arg>javafx.web/com.sun.webkit.dom=ALL-UNAMED</arg>
                    </compilerArgs>
                </configuration>
            </plugin>
        </plugins>
    </build>

If I use the Maven shade plugin, I am able to bypass this issue. I think it has got to do with how JPMS security works, but I cannot figure out how to bypass this. I tried add-exports, and add-opens in various combinations, but it did not help me. What am I doing wrong?

BTW, I want to map the WebKit DOM to the JSoup dom element, as they give a nice API for CSS selectors.

Update I am adding an additional stack trace of the error

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$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NoClassDefFoundError: com/sun/webkit/dom/DomMapper
    at xyz.jphil.internal_browser.TestApp.start(TestApp.java:86)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$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$3(WinApplication.java:174)
    ... 1 more
Caused by: java.lang.ClassNotFoundException: com.sun.webkit.dom.DomMapper
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 10 more

Answer 1

The solution for this problem lies in using using --patch-module. As I have added a class - com.sun.webkit.dom.DomMapper which is completely sealed by JPMS. The reason why I added DomMapper in the com.sun.webkit.dom.DomMapper was to access some package-private functions.

However, I see that can be easily avoided so I am choosing to avoid using those package-private functions. With this --patch-module is not required, which is also not a recommended thing to do as per JPMS documentation. Now the solution is simpler. Adding --add exports is enough (which is already there in the POM) and I am able to get it working.

Finally exporting the entire program as a farjar using maven shade plugin for example, also works. This I am adding just for information.

This answer is based on comments and valuable inputs by Jewelsea and Slaw. Further notes:

• This example shows the public (although internal) functions of the com.sun.webkit.dom are quite good as it is, gist.github.com/jewelsea/6722397
• The problem I created by making a class inside com.sun.webkit.dom is called split-package - read here How split packages are avoided in Java 9