Using JavaFX with Intellij IDEA

Question

I've followed a tutorial precisely and I can't seem to get it to work. The tutorial is under JavaFX and Intellij Non-modular from IDE sections: https://openjfx.io/openjfx-docs/#install-java

Here is the error message I receive when trying to run the default Intellij Idea JavaFX project:

"C:\Program Files\Java\jdk-11.0.1\bin\java.exe" --module-path %PATH_TO_FX% --add-modules=javafx.controls,javafx.fxml --add-modules javafx.base,javafx.graphics --add-reads javafx.base=ALL-UNNAMED --add-reads javafx.graphics=ALL-UNNAMED "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2018.3\lib\idea_rt.jar=53491:C:\Program Files\JetBrains\IntelliJ IDEA 2018.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\Users\jonat\IdeaProjects\Tawe-Lib FX\out\production\Tawe-Lib FX;C:\Program Files\Java\javafx-sdk-11.0.1\lib\src.zip;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx-swt.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.web.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.base.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.fxml.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.media.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.swing.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.controls.jar;C:\Program Files\Java\javafx-sdk-11.0.1\lib\javafx.graphics.jar" sample.Main
Error occurred during initialization of boot layer
java.lang.module.FindException: Module javafx.base not found

Process finished with exit code 1

This makes little sense to me as I can see javafx.base under lib on the sidebar:

The path leading to jdk-11.0.1 and javafx-sdk-11.0.1:

C:\Program Files\Java

Java is installed:

C:\Users\jonat>java --version
openjdk 11.0.1 2018-10-16
OpenJDK Runtime Environment 18.9 (build 11.0.1+13)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.1+13, mixed mode)

JAVA_HOME variable (mentioned in guide) is set:

C:\Users\jonat>echo %JAVA_HOME%
C:\Program Files\Java\jdk-11.0.1

PATH_TO_FX variable is set:

C:\Users\jonat>echo %PATH_TO_FX%
C:\Program Files\Java\javafx-sdk-11.0.1\lib

I have really no idea where to go from here. I have followed the tutorial precisely, and it does not work. Any help would be greatly appreciated and if you require more info please just drop a comment about it.

Answer 1

Based on the posted command line, this is what IntelliJ applies to run your project:

"C:\Program Files\Java\jdk-11.0.1\bin\java.exe" --module-path %PATH_TO_FX% --add-modules=javafx.controls,javafx.fxml

So the issue is quite clear: In the VM options you have set verbatim what the tutorial says:

But you haven't applied your real path for PATH_TO_FX, as it is suggested in the picture inserted after that command in the tutorial:

IntelliJ doesn't resolve that variable and the module path is not set, hence you get the expected error that reveals that the JavaFX modules are not found:

Error occurred during initialization of boot layer
java.lang.module.FindException: Module javafx.controls not found

Solution

This can be solved in two ways:

1. Apply your path:

Edit run configurations, and in the VM options add your path:

--module-path "C:\Program Files\Java\javafx-sdk-11.0.1\lib" --add-modules=javafx.controls,javafx.fxml

Apply, and run. It should work.

2. Add the environment variable

You can also set an environment variable. Go to IntelliJ->File->Settings->Appearance & Behavior->Path Variables, and add PATH_TO_FX, with the path to the lib folder:

And then you can use the literals $PATH_TO_FX$ (Does not work for IntelliJ IDEA 2021.1 (Community Edition) on Windows) or ${PATH_TO_FX} in the VM options:

--module-path ${PATH_TO_FX} --add-modules=javafx.controls,javafx.fxml

Apply, and run.

Note that this is a more permanent solution that can be apply to any other JavaFX project.