在Spring框架下手工获取Bean的方式

ApplicationContext ac = new FileSystemXmlApplicationContext("applicationContext.xml");
    ac.getBean("beanId");

ApplicationContext ac1 = WebApplicationContextUtils.getRequiredWebApplicationContext(ServletContext sc)

ApplicationContext ac2 = WebApplicationContextUtils.getWebApplicationContext(ServletContext sc)

    ac1.getBean("beanId");

    ac2.getBean("beanId");

UserManager userManager = (UserManager) WebApplicationContextUtils.getRequiredWebApplicationContext(pageContext.getServletContext()).getBean("userManager");