File outerJar = new File(path);
assertTrue(outerJar.getAbsolutePath()+" exists", outerJar.exists());
JarFile jf = new JarFile(outerJar);
URL rootURL = outerJar.getParentFile().toURL();
VFSContextFactory factory = VFSContextFactoryLocator.getFactory(rootURL);
VFSContext context = factory.getVFS(rootURL);
JarEntry jar1 = jf.getJarEntry("jar1.jar");
URL jar1URL = new URL(outerJar.toURL(), "jar1.jar");
ZipInputStream jis1 = new ZipInputStream(jf.getInputStream(jar1));
NestedJarFromStream njfs = new NestedJarFromStream(context, null, jis1, jar1URL, jar1);