* @param rootDir
         *            The root directory.
         */
        public JarFileTraverser(final JarFile jarFile, final String rootPackage, final String rootDir) {
            this.jarFile = jarFile;
            this.rootPackage = rootPackage;
            this.rootDir = rootDir;
        }

        /**
         * Constructs an instance.
         *
         * @param url

import java.io.IOException
import java.util.Properties
import java.util.jar.JarEntry
import java.util.jar.JarFile


data class PluginEntry(val pluginId: String, val implementationClass: String)


fun pluginEntriesFrom(jar: File): List<PluginEntry> = try {
    JarFile(jar, false).use { jarFile ->
        jarFile.entries().asSequence().filter {
            isGradlePluginPropertiesFile(it)
        }.map { pluginEntry ->

                if (form.jarFile == null) {
                    throwValidationError(messages -> messages.addErrorsPluginFileIsNotFound(GLOBAL, form.id), this::asListHtml);
                }
                if (!form.jarFile.getFileName().endsWith(".jar")) {
                    throwValidationError(messages -> messages.addErrorsFileIsNotSupported(GLOBAL, form.jarFile.getFileName()),

    private val unshadedPackages: Set<String>,
    private val ignorePackages: Set<String>
) {

    fun analyze(jarFile: File, classesDir: File, manifestFile: File, buildReceipt: File): ClassGraph {
        val classGraph = classGraph()

        val jarUri = URI.create("jar:${jarFile.toPath().toUri()}")
        FileSystems.newFileSystem(jarUri, emptyMap<String, Any>()).use { jarFileSystem ->

        for (final WebResource possibleJar : possibleJars) {
            if (possibleJar.isFile() && possibleJar.getName().endsWith(".jar")) {
                try (final JarFile jarFile = new JarFile(possibleJar.getCanonicalPath())) {
                    final Manifest manifest = jarFile.getManifest();
                    if (manifest != null && manifest.getEntries() != null) {
                        final Attributes attributes = manifest.getMainAttributes();

        }
    }

    private
    fun openJarFile(file: File) =
        openJars.computeIfAbsent(file, ::JarFile)

    override fun close() {
        openJars.values.forEach(JarFile::close)
    }
}


/**
 * See https://docs.oracle.com/javase/8/docs/technotes/tools/findingclasses.html#userclass
 */
private
val File.isClassPathArchive

                                            <label for="jarFile" class="col-md-3 text-sm-right col-form-label"><la:message
                                                    key="labels.plugin_jar_file"/></label>
                                            <div class="col-md-9 text-sm-right col-form-label">
                                                <input id="jarFile" type="file" name="jarFile" class="form-control-file"/>

     *
     * @param conn
     *            {@link JarURLConnection}. Must not be {@literal null}.
     * @return {@link JarFile}
     */
    public static JarFile getJarFile(final JarURLConnection conn) {
        assertArgumentNotNull("conn", conn);

        try {
            return conn.getJarFile();
        } catch (final IOException e) {

    /**
     * Default constructor.
     */
    public InstallForm() {
        // Default constructor
    }

    /** JAR file containing the plugin to install */
    public MultipartFormFile jarFile;

     */
    public ExtensionDescriptor build(File extensionJar) throws IOException {
        ExtensionDescriptor extensionDescriptor = null;

        if (extensionJar.isFile()) {
            try (JarFile pluginJar = new JarFile(extensionJar, false)) {
                ZipEntry pluginDescriptorEntry = pluginJar.getEntry(getExtensionDescriptorLocation());

                if (pluginDescriptorEntry != null) {