动态代理

1. 例子
   动态代理ArrayList

        List list = new ArrayList();

        List proxyList = (List)Proxy.newProxyInstance(list.getClass().getClassLoader(),
                list.getClass().getInterfaces(),
                new InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        // something before
                        Object obj = method.invoke(list, args);
                        // something after
                        return obj;
                    }
                });
        proxyList.add("test");
        System.out.println(list.get(0));