There are many ways to check your bean is singleton or not. For your confirmation if you want to check just create a Standalone application and load your configuration file from BeanFactory or ApplicationContext thn get your bean more thn one time using getBean() method.
And finally print object and check the address of that objects.It should be same. For example you can see below code in main method....
Resource resource = new FileSystemResource("com/spring/example/spring.cfg.xml");
BeanFactory factory = new XmlBeanFactory(resource);