common_helper/src/main/java/com/xiongyingqi/util/ClassLookupHelper.java
private static Collection<URLClassLoader> getClassLoaders(ClassLoader baseClassLoader) {
        Collection<URLClassLoader> loaders = new ArrayList<URLClassLoader>(8);
        ClassLoader loader = baseClassLoader;
        while (loader != null) {
            if ("sun.misc.Launcher$ExtClassLoader".equals(loader.getClass().getName())) {
                break;
            }
            if (loader instanceof URLClassLoader) {
                loaders.add((URLClassLoader) loader);
            }
            loader = loader.getParent();
        }
        return loaders;
    }
private static Collection<URLClassLoader> getClassLoaders(ClassLoader baseClassLoader) {
        Collection<URLClassLoader> loaders = new ArrayList<URLClassLoader>(8);
        ClassLoader loader = baseClassLoader;
        while (loader != null) {
            if ("sun.misc.Launcher$ExtClassLoader".equals(loader.getClass().getName())) {
                break;
            }
            if (loader instanceof URLClassLoader) {
                loaders.add((URLClassLoader) loader);
            }
            loader = loader.getParent();
        }
        return loaders;
    }
根据 baseClassLoader 找到所有的祖先 URLClassLoader (包括自己)