首先,最重要的, @Autowired的就是用来来消除 set ,get方法.
有些介绍,如著名的马士兵,说要在set方法上进行注入.我当时就看不明白了,既然只取消了一个GET,这个@Autowired还有什么屁用.不是瞎折腾么.还要用@Qualifier来帮忙指定BEAN.
如下:
// @Autowired // public void setUserDAO(@Qualifier("userDAOImpl") UserDAO userDAO) { // this.userDAO = userDAO; // }
后来自己试了一下,在SPRING2.5和3.0下,都不用这样.
直接使用
Autowired 即可
@Autowired private UserDAO userDAO;
也不需要在applicationContext.xml中加入:
<!-- 该 BeanPostProcessor 将自动对标注 @Autowired 的 Bean 进行注入 --> <bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
贴出我的SPRING配置文件
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <context:annotation-config /> <bean id="userDAOImpl" class="com.bjsxt.dao.impl.UserDAOImpl"> </bean> <bean id="userService" class="com.bjsxt.service.UserService" > </bean> </beans>
public class UserService { @Autowired private UserDAO userDAO; public void add(User user) { userDAO.save(user); } // @Autowired // public void setUserDAO(@Qualifier("userDAOImpl") UserDAO userDAO) { // this.userDAO = userDAO; // } }
public class UserServiceTest { @Test public void testAdd() throws Exception { ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml"); UserService service = (UserService)ctx.getBean("userService"); service.add(new User()); } }
时间: 2024-07-28 23:05:56