Spring实现Aware接口自定义获取bean的两种方式
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:
@ServicepublicclassBeanFactoryHelperimplementsBeanFactoryAware{ privatestaticBeanFactorybeanFactory; @Override publicvoidsetBeanFactory(BeanFactorybeanFactory)throwsBeansException{ this.beanFactory=beanFactory; } publicstaticObjectgetBean(StringbeanName){ if(beanFactory==null){ thrownewNullPointerException("BeanFactoryisnull!"); } returnbeanFactory.getBean(beanName);}}
还有一种方式是实现ApplicationContextAware接口,代码也很简单:
@Service publicclassApplicationContextHelperimplementsApplicationContextAware{ privatestaticApplicationContextapplicationContext; @Override publicvoidsetApplicationContext(ApplicationContextapplicationContext)throwsBeansException{ this.applicationContext=applicationContext; } publicstaticObjectgetBean(StringbeanName){ if(applicationContext==null){ thrownewNullPointerException("ApplicationContextisnull!"); } returnapplicationContext.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 publicvoidtest()throwsSQLException{ //通过从classpath中加载spring-mybatis.xml实现bean的获取 ApplicationContextcontext=newClassPathXmlApplicationContext("spring-mybatis.xml"); IUserServiceuserService=(IUserService)context.getBean("userService"); Useruser=newUser(); user.setName("test"); user.setAge(20); userService.addUser(user); }
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