From an email thread:


A quick System.nanoTime() measuring of

        try (FileSystem fs = FileSystems.newFileSystem(
                          new URI("jar", ...), Collections.emptyMap())) {}

        try (ZipFile zf = new ZipFile(args[0])) {}

on rt.jar suggests zipfile initialization is about 5 times faster than zipfs's.
Something need to be done.