基于xml的自动装配之场景模拟

基于xml的自动装配之场景模拟

自动装配：

根据指定的策略，在 IOC 容器中匹配某一个 bean ，自动为指定的 bean 中所依赖的类类型或接口类型属性赋值

UserController 类

public class UserController {

    private UserService userService;

    public UserService getUserService() {
        return userService;
    }

    public void setUserService(UserService userService) {
        this.userService = userService;
    }

    public void saveUser(){
        userService.saveUser();
    }
}

UserService 接口

public interface UserService {
    /**
     * 保存用户信息
     */
    void  saveUser();
}

UserServiceImpl 实现类

public class UserServiceImpl implements UserService {

    private UserDao userDao;

    public UserDao getUserDao() {
        return userDao;
    }

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    
    /**
     * 保存用户信息
     */
    @Override
    public void saveUser() {
        userDao.saveUser();
    }
}

UserDao 接口

public interface UserDao {

    /**
     * 保存用户信息
     */
    void saveUser();
}

UserDaoImpl 实现类

public class UserDaoImpl implements UserDao {
    /**
     * 保存用户信息
     */
    @Override
    public void saveUser() {
        System.out.println("保存成功");
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="userController" class="com.atguigu.spring.controller.UserController">
        <property name="userService" ref="userService"></property>
    </bean>

    <bean id="userService" class="com.atguigu.spring.service.impl.UserServiceImpl">
        <property name="userDao" ref="userDao"></property>
    </bean>

    <bean id="userDao" class="com.atguigu.spring.dao.impl.UserDaoImpl"></bean>
</beans>

测试类

public class AutowireByXmlTest {
    @Test
    public void testAutowire(){
        ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-autowrire-xml.xml");
        UserController userController = ioc.getBean(UserController.class);
        userController.saveUser();
    }
}