如何从Spring获取实例化的bean列表？

例如：

 public static List<Object> getInstantiatedSigletons(ApplicationContext ctx) { List<Object> singletons = new ArrayList<Object>(); String[] all = ctx.getBeanDefinitionNames(); ConfigurableListableBeanFactory clbf = ((AbstractApplicationContext) ctx).getBeanFactory(); for (String name : all) {     Object s = clbf.getSingleton(name);     if (s != null)         singletons.add(s); } return singletons;    }