Proxool 注册shutdown hook的代码

通过API取得当前Runtime环境， 反射调用Runtime的addShutdownhook方法。感觉为什么不直接调用却用反射，用意何在           

 

        Thread t = new Thread(this);
        t.setName("ShutdownHook");
        Runtime runtime = Runtime.getRuntime();

            Method addShutdownHookMethod = Runtime.class.getMethod("addShutdownHook", new Class[] {Thread.class});
            addShutdownHookMethod.invoke(runtime, new Object[] {t});
            ProxoolFacade.setShutdownHook(t);