在使用spring编程时,常常会遇到想根据bean的名称来获取相应的bean对象,这时候,就可以通过实现beanfactoryAware来满足需求,代码很简单:
@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); } }
还有一种方式是实现ApplicationContextAware接口,代码也很简单:
@Service public 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); } }
上面两种方法,只有容器启动的时候,才会把 beanfactory 和 ApplicationContext 注入到自定义的helper类中,如果在本地junit测试的时候,如果需要根据bean的名称获取bean对象,则可以通过ClasspathXmlApplicationContext来获取一个ApplicationContext,代码如下:
@Test public void test() throws sqlException { //通过从classpath中加载spring-mybatis.xml实现bean的获取 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); }
总结
以上就是小编分享给大家的Java编程实现Aware接口自定义获取bean的两种方式的全部内容,希望对大家有所帮助。如果有什么问题,可以留言,小编会及时回复大家。感谢大家对本站的支持!