javafx-maven-plugin | Maven plugin for JavaFX | Plugin library

From the comments, you seem to be using some less common libraries. Sometimes, those kinds of libraries are not updated to be compatible with the Java Platform Module System. I think it is probably safe to assume that unless you know otherwise.

Defining a non-modular project

The easiest way to deal with such dependencies is to make your project non-modular: delete the module-info.java.

But JavaFX itself is only supported as modules. So, even though your project and its dependencies are non-modular, you should still place the JavaFX libraries on the module path.

Using a JDK which includes JavaFX

To accomplish such a setup (non-modular application using JavaFX modules), the easiest way is to rely on a JDK or JRE that includes JavaFX modules, for example, the Zulu JDK FX distribution or the Liberica Full JDK distribution. It is important to use the correct distribution as the base JDK distributions for Zulu and Liberica do not include JavaFX.

Using a base JDK which does not include JavaFX

With a bit more work, you can use OpenJDK. You can do this by sourcing the JavaFX modules from either the maven repository with a build tool, or a manual download of the modules and SDK from Gluon. In all your build and execution steps, you need to ensure that all of those modules are on the module path and declared to the module system via either VM arguments or a module-info.java.

Building with Maven

For a Maven build, you need to add each module to the module path individually, as they are all in separate directories in the local .m2 repository (modern Maven systems and some IDEs, such as Idea, will do that automatically, other IDEs such as VSCode may not).

Building with the SDK

Alternately, don't add dependencies on the JavaFX modules via Maven. Instead, download the JavaFX SDK and add the JavaFX modules there via VM arguments --module-path and --add-modules. This process for adding JavaFX modules to OpenJDK is documented in the getting started documentation at openjfx.io.

A note on openjfx.io Maven archetypes

Note that the openjfx.io getting started documentation around this mentions maven archetypes. My advice is not to use those as they are really difficult to work with if you try to use them from IDEs. Instead, use the Idea new JavaFX project wizard, either keeping the module-info.java it generates for a modular project or removing it and manually specifying JavaFX module VM arguments for a non-modular project.

Issues with your project build

In terms of your actual project, I encountered the same error that duffymo pointed out in the comments:

I can't resolve all the dependencies for web3jm-evm from Maven Central. It's pulling in a bunch of JARs from org.hyperledger.besu that aren't in Maven Central.

So I was unable to build or test it.

If you define a module-info.java file and you want to use the javafx.media module, you need to require that module in your module-info (as suggested by kleopatra in comments).

Try to create a new Class with a main method that calls the main Method of your Application class and use it as entry point.

The solution with JPackageScriptFX is the best. Thanks Jewelsea. Jmods from javafx copied to C:/jdk/jmods. Then in bat file

I am missing the jmods directory in my jdk. On Fedora jmods are a separate install https://fedora.pkgs.org/35/fedora-x86_64/java-11-openjdk-jmods-11.0.12.0.7-4.fc35.x86_64.rpm.html

Run sudo dnf install java-11-openjdk-jmods

This is unrelated to Maven, it is an access error caused by incorrect configuration of the Java module system for your application.

The error message tells you what is wrong:

Caution

JavaFX has keyboard handling in-built.

Absolutely do not do this unless you need some capability not built into JavaFX.

That said . . . if you really need to do this . . .

I got this to work via the following steps:

1. Created a new JavaFX project via the Idea New JavaFX project wizard.

2. Added a dependency to JNativeHook 2.2-SNAPSHOT.

   • Snapshot was required because 2.2.1 release module-info would not work for me.

The error message indicates that you have to specify the main class without module name. Just use the fully qualified class name there. A fully qualified never contains a slash as it is not a path name. So in your case the fully qualified class name is including the XML tags around (the main class is used two times in your pom.xml and have to be corrected in both cases):

I recently encountered the same problem here:

When executing the command mvn javafx:run, the javafx-maven-plugin produces the following: [WARNING] Module name not found in . Module name will be assumed from module-info.java. The mainClass configuration attribute is the "fully qualified name, with or without module name." While the warning can be safely ignored, adding the module name eliminates the warning: