Spring中使用两种Aware接口自定义获取bean

本文内容纲要:Spring中使用两种Aware接口自定义获取bean

  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:

@Service

public 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);

}

本文内容总结:Spring中使用两种Aware接口自定义获取bean

原文链接:https://www.cnblogs.com/handsomeye/p/6277510.html

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