Java:spring框架(2)IOC注解

一.创建XML文件,配置XML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.xsd
        http://www.springframework.org/schema/context
 http://www.springframework.org/schema/context/spring-context.xsd">
 <!-- bean definitions here -->

    <!--开启注解扫描-->
/*
*  1. base-package属性: 设置包名,程序将会在设置的包里面扫描注解
*/
    <context:component-scan base-package="com.company"></context:component-scan>

</beans>

二.创建User类,设置类注解

/*
*  1. 设置类注解方式: @Component(value = "user")
                                     @Service(value="user")
*  2. value属性: 随意设置,标记注解类
*/
//@Component(value = "user")
@Service(value = "user")
public class User {
        public void UserTest(){
        System.out.println("我是User");
    }
}

三.创建UserService类,设置属性注解

/*
*  1. 设置属性注解方法: @Autowired  //自动装载,自动扫描属性
                                         @Resource(name = "userDao")
*  2.name 属性: 随意设置,标记注解属性
*/
@Component("userService")   //装载类
public class UserService {
//    @Autowired  //自动装载
    @Resource(name = "userDao")   //装载属性
    private UserDao userDao;
    public void ServiceTest(){
        System.out.println("我是UserService");
        //通过属性注解获取的类对象,调用类方法
        userDao.UserDaoTest();
    }
}

@Service("userDao")
public class UserDao {
    public void UserDaoTest(){
        System.out.println("我是UserDao");
    }
}

四.创建测试类,编写代码实现

/*
*  1.使用ApplicationContext加载XML配置文件
*  2.通过getBean()方法以及类注解中的value值,获取对应的类对象
*/
ApplicationContext context = new ClassPathXmlApplicationContext("springUser");
User user = (User) context.getBean("user");
user.UserTest();

//使用注解装载对象
UserService userService = (UserService) context.getBean("userService");
userService.ServiceTest();