Builder (ClassLoader classLoader) { if (classLoader instanceof URLClassLoader) { return urls(((URLClassLoader)classLoader).getURLs()); } String[] parts = System.getProperty("java.class.path").split(File.pathSeparator); myURLs = new ArrayList<>(parts.length); for (String s : parts) { try { myURLs.add(new File(s).toURI().toURL()); } catch (IOException ignored) { } } return this; }