Spring实现Aware接口自定义获取bean的两种方式

时间:2022-04-13 11:53:58

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:

?
1
2
3
4
5
6
7
8
9
10
11
@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:

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
@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 BeanFactoryApplicationContext 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:

?
1
2
3
4
5
6
7
8
9
10
@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!

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