def javaProjects() {
    return subprojects.findAll { new File(it.projectDir, "src").exists() }
}

subprojects {
    configure(javaProjects()) {
        apply plugin: "java"

        group 'com.example'
        version '0.0.1-SNAPSHOT'

        repositories {
            mavenCentral()
        }

        test {
            useJUnitPlatform()
        }
    }
}