You can open this sample inside an IDE using the IntelliJ’s Gradle import or Eclipse Buildship.

This sample shows how artifact transforms can be utilised to turn traditional Java libraries into Java Modules by adding additional information to the corresponding Jars. For that, a plugin called extra-java-module-info is defined in the buildSrc folder. This plugin can be copied into another project and adjusted as needed to solve use cases where it is desired to treat every dependency as a Java Module.

The example defines an application that relies on libraries from Maven central where some of them are not available as modules. It uses commons-cli (not a module) to parse the command line arguments, which can contain a JSON String, and gson (a proper module) to parse the JSON string. It also utilises commons-lang3 (an automatic module) and commons-beanutils (not a module) which brings in some additional dependencies that are also not modules.

By configuring our own extra-java-module-info plugin, we add information to turn the legacy libraries into modules.

application/build.gradle.kts
extraJavaModuleInfo {
    // This does not have to be a complete description (e.g. here 'org.apache.commons.collections' does not export anything here).
    // It only needs to be good enough to work in the context of this application we are building.
    module("commons-beanutils-1.9.4.jar", "org.apache.commons.beanutils", "1.9.4") {
        exports("org.apache.commons.beanutils")

        requires("org.apache.commons.logging")
        requires("java.sql")
        requires("java.desktop")
    }
    module("commons-cli-1.4.jar", "org.apache.commons.cli", "3.2.2") {
        exports("org.apache.commons.cli")
    }
    module("commons-collections-3.2.2.jar", "org.apache.commons.collections", "3.2.2")
    automaticModule("commons-logging-1.2.jar", "org.apache.commons.logging")
}
application/build.gradle
extraJavaModuleInfo {
    // This does not have to be a complete description (e.g. here 'org.apache.commons.collections' does not export anything here).
    // It only needs to be good enough to work in the context of this application we are building.
    module('commons-beanutils-1.9.4.jar', 'org.apache.commons.beanutils', '1.9.4') {
        exports('org.apache.commons.beanutils')

        requires('org.apache.commons.logging')
        requires('java.sql')
        requires('java.desktop')
    }
    module('commons-cli-1.4.jar', 'org.apache.commons.cli', '3.2.2') {
        exports('org.apache.commons.cli')
    }
    module('commons-collections-3.2.2.jar', 'org.apache.commons.collections', '3.2.2')
    automaticModule('commons-logging-1.2.jar', 'org.apache.commons.logging')
}

You can run the example application like this:

run --args='-json {"message":"Hello","receivers":["Lisa","John"]} -debug'

For more information, see Java Module support in the Java Library Plugin and Java Module support in the Application Plugin.