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;

    }