Bundle JavaFX app with openjdk 11 + runtime

Question

I\'ve created a small HelloWorld Java app that relies on OpenJDK 11 and JavaFX. The app is packaged in a jar file which can only be run if I have installed Java 11 and JavaF

Answer 1

(Using jdk14)

Starting by the fact that in order to use jlink your main jar should be a module.

How? Consider that you have a maven project. You just need to include module-info.java inside src/main/java dir and make sure that you require the modules that your app needs and you export the package that contains your main class. In most cases you will get a compile-time error when missing a requires. Have in mind that non-modular dependencies become automatic modules.

You can use maven's copy-dependencies to make sure that all dependencies are copied under target/lib during mvn package.

next step: jlink

Since jlink maven plugin is still in alpha, you can use command-line.

NOTES:

• jlink will create a self-contained bundle directory that contains
  • main app module
  • app dependencies
  • jdk required modules
  • app launcher (optional)
• jlink bundle targets one platform at a time. By default it is the current platform.
• javafx runtime modules are also platform-specific. But since they are not part of the jdk we need to always provide the module-path containing them.
• javafx runtime modules can be downloaded from web, or from maven repo by using the corresponding target platform classifier (win/linux/mac).
• jlink can also create cross-platform bundles. Just include the target platform modules to the --module-path (e.g. from linux: download windows jdk/ javafx and add their jmods dirs to module-path).

jlink command

Case 1: build and target platforms are the same

NOTE: /path-to/javafx-mods needs to be provided to your modulepath unless you copy the required javafx deps under lib/ using maven (copy-dependencies).

jlink --launcher run=jdk14Example/com.example.javafx.app.Main \
--module-path ./lib:javafx-jdk14-example-1.0.0.jar:/path-to/javafx-mods \
--add-modules=jdk14Example --output app-bundle

Case 2: build and target platforms are differrent

# Building from linux for windows
jlink --launcher run=jdk14Example/com.example.javafx.app.Main  \
--module-path ./lib:javafx-jdk14-example-1.0.0.jar:/path-to/jdk-win/jmods:/path-to/javafx-mods-win \
--add-modules=jdk14Example --output app-bundle

Conclusion:

In both of the above cases you get a directory with a self-contained application which can run on a workstation with no java/javafx installed.

# if jlink targeted linux
app-bundle/bin/run

# if jlink targeted windows
app-bundle/bin/run.bat

# if jlink targeted mac
app-bundle/bin/run