getLoadedPackageGroupVersions.kt

fun getLoadedPackageGroupVersions(detailed: Boolean = false, vararg excludePrefixes: String): String {
    fun getProductDetails(packageGroup: List<Package>): String {
        val samplePackage = packageGroup.first()
        val prodTitle =
            "\t${samplePackage.implementationTitle} " +
                    "v(${samplePackage.implementationVersion}) by ${samplePackage.implementationVendor}"
        if (!detailed)
            return prodTitle

        val details = packageGroup.map { "\t\t" + it.name }.sorted().joinToString("\n")
        return prodTitle + "\n" + details
    }

    val packages = Package.getPackages()
    val filteredPackages = packages.filterNot {
        it.name.startsWithAny(*excludePrefixes)
    }
    val productGroups =
        filteredPackages.groupBy { listOf(it.implementationTitle + it.implementationVersion + it.implementationVendor) }

    val versionsText =
        productGroups
            .values
            .map { getProductDetails(it) }
            .sorted()
            .joinToString("\n")

    return "Versions of ${filteredPackages.size} loaded packages in ${productGroups.size} products:\n${versionsText}"
}

object App {
    @JvmStatic
    fun main(args: Array<String>) {
        println(getLoadedPackageGroupVersions(detailed = false, "java.", "javax.", "jdk.", "sun.", "com.sun."))
        println(getLoadedPackageGroupVersions(detailed = true, "java.", "javax.", "jdk.", "sun.", "com.sun."))
    }
}