在启动项目时显示加载spring的配置文件成功了,使用时却获取不到,为什么?
spring中配置了: <!--spring自动扫描注解-->
<context:component-scan base-package="com.fafasj"></context:component-scan>
web.xml配置了:
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
有两个类
//UserServiceImpl.class
@Component("userService")//将当前类交给spring管理
public class UserServiceImpl implements UserService {
@Autowired
private UserDao userDao;
@Override
public void say() {
System.out.println("我说话了哦。。。"+userDao);//这里userDao为 null ?
userDao.say();
}
}
//UserDaoImpl.class
@Component("userDao")
public class UserDaoImpl implements UserDao {
@Override
public void say() {
System.out.println("我也说话了哈");
}
}