在使用spring編程時(shí)，常常會(huì)遇到想根據(jù)bean的名稱來獲取相應(yīng)的bean對(duì)象，這時(shí)候，就可以通過實(shí)現(xiàn)BeanFactoryAware來滿足需求，代碼很簡(jiǎn)單：
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@Servicepublic class BeanFactoryHelper implements BeanFactoryAware { private static BeanFactory beanFactory; @Override public void setBeanFactory(BeanFactory beanFactory) throws BeansException { this.beanFactory = beanFactory; } public static Object getBean(String beanName){ if(beanFactory == null){ throw new NullPointerException("BeanFactory is null!"); } return beanFactory.getBean(beanName); } } |
還有一種方式是實(shí)現(xiàn)ApplicationContextAware接口，代碼也很簡(jiǎn)單：
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@Servicepublic class ApplicationContextHelper implements ApplicationContextAware { private static ApplicationContext applicationContext; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.applicationContext = applicationContext; } public static Object getBean(String beanName){ if(applicationContext == null){ throw new NullPointerException("ApplicationContext is null!"); } return applicationContext.getBean(beanName); }} |
上面兩種方法，只有容器啟動(dòng)的時(shí)候，才會(huì)把 BeanFactory 和 ApplicationContext 注入到自定義的helper類中，如果在本地junit測(cè)試的時(shí)候，如果需要根據(jù)bean的名稱獲取bean對(duì)象，則可以通過ClassPathXmlApplicationContext來獲取一個(gè)ApplicationContext，代碼如下：
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@Test public void test() throws SQLException { //通過從classpath中加載spring-mybatis.xml實(shí)現(xiàn)bean的獲取 ApplicationContext context = new ClassPathXmlApplicationContext("spring-mybatis.xml"); IUserService userService = (IUserService) context.getBean("userService"); User user = new User(); user.setName("test"); user.setAge(20); userService.addUser(user); } |
總結(jié)
以上就是小編分享給大家的Java編程實(shí)現(xiàn)Aware接口自定義獲取bean的兩種方式的全部?jī)?nèi)容，希望對(duì)大家有所幫助。如果有什么問題，可以留言，小編會(huì)及時(shí)回復(fù)大家。感謝大家對(duì)本站的支持！
原文鏈接：http://www.cnblogs.com/handsomeye/p/6277510.html
