如何在jar文件中创建jar类加载器？

Question

假设下面的jar文件遵循分层结构。

application.jar
  demo
    Main.class
  lib
    dep.jar
      dep
        DependencyMain.class

我想用lib / dep.jar创建类加载器并加载DependencyMain类。

private static void loadTest() throws Exception {
  File jarFile = new File(Main.class.getProtectionDomain().getCodeSource().getLocation().getPath());
  final JarFile jar = new JarFile(jarFile);
  final Enumeration<JarEntry> entries = jar.entries();

  String file = "jar:" + jarFile.toURI() + "!/";

  while (entries.hasMoreElements()) {
    JarEntry entry = entries.nextElement();
    if(entry.getName().endsWith("dep.jar") {
      // HAVE TO CHANGE 
      URL jarUrl = new URL(file + name);
      final JarURLConnection connection = (JarURLConnection)jarUrl.openConnection();
      final URL url = connection.getJarFileURL();

      ClassLoader classLoader = new URLClassLoader(new URL[]{jarUrl}, Main.class.getClassLoader());

      Class<?> clazz = classLoader.loadClass("dep.DependencyMain");
      // i want to load dep.DependencyMain class at here
      break;
    }
  }
}