学spring入门的时候就得先学会使用如何在普通的javabean里获取application.xml中配置的bean

java：

  ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
  BeanFactory factory = (BeanFactory) context;
  UserServiceImpl userservice = (UserServiceImpl ) factory.getBean("userservice");

   或者：

    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
    context.start();
    DemoService demoService = (DemoService) context.getBean("demoService"); // 获取bean
    String hello = demoService.sayHello("world"); // 执行bean方法