Java sun.net.www.protocol.file存在从1.6 jdk到11 jdk的迁移代码问题

我在迁移使用

sun.net.*

和

sun.net.www.protocol.file.FileURLConnection的旧代码时遇到问题
Ant无法在jdk 11上构建项目，因为
FileURLConnection
来自基本包的8/9版内部类。FileURLCOnnection用于检查返回类的实例，所以我需要知道如何在不破坏逻辑的情况下替换这个片段（片段belowe）

您应该能够替换：

connection instanceof FileURLConnection

作者：

非常感谢。你是我的英雄：D
    for (URL url = null; resources.hasMoreElements()
                && ((url = resources.nextElement()) != null); ) {
                try {
                    connection = url.openConnection();

                    if (connection instanceof JarURLConnection) {
                        checkJarFile((JarURLConnection) connection, pckgname,
                            classes);
                    } else if (connection instanceof FileURLConnection) {
                        try {
                            checkDirectory(
                                new File(URLDecoder.decode(url.getPath(),
                                    "UTF-8")), pckgname, classes);
                        } catch (final UnsupportedEncodingException ex) {
                            throw new ClassNotFoundException(
                                pckgname
                                    + " does not appear to be a valid package (Unsupported encoding)",
                                ex);
                        }
                    } else
                        throw new ClassNotFoundException(pckgname + " ("
                            + url.getPath()
                            + ") does not appear to be a valid package");
                } catch (final IOException ioex) {
                    throw new ClassNotFoundException(
                        "IOException was thrown when trying to get all resources for "
                            + pckgname, ioex);
                }
            }

connection instanceof FileURLConnection

"file".equals(url.getProtocol())