Basic Module System

Modules.java

	public static void main(String[] args) {

		File folder = new File(".", "modules");
		List<Class<?>> clazzez = Lists.newArrayList();
		for (File file : folder.listFiles())
			try {
				Class<?> clazz = getModule(file);
				if (clazz != null)
					clazzez.add(clazz);
			} catch (Exception e) {
				e.printStackTrace();
			}

		for (Class<?> clazz : clazzez) {
			Module m = clazz.getAnnotation(Module.class);
			System.out.println(m.name());
			System.out.println(m.author());
			System.out.println(m.version());
			try {
				clazz.newInstance();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

	}

	public static Class<?> getModule(File file) {
		try (JarFile jarFile = new JarFile(file)) {
			Enumeration<JarEntry> en = jarFile.entries();
			URLClassLoader child = new URLClassLoader(new URL[] { file.toURI().toURL() }, getClass().getClassLoader());
			while (en.hasMoreElements()) {
				JarEntry next = en.nextElement();
				String name = next.getName();
				if (name.endsWith(".class")) {
					name = name.replace('/', '.');
					Class<?> clazz = Class.forName(name.substring(0, name.length() - 6), true, child);
					if (clazz.getAnnotation(Module.class) != null)
						return clazz;
				}
			}
		} catch (IOException | ClassNotFoundException e) {
			e.printStackTrace();
			return null;
		}
		return null;
	}