01Spring基于xml的IOC配置

1、创建一个普通的maven工程

1.1 选择maven，不用骨架，点击下一步。

1.2 填写GroupId、ArtifactId、Version。填完点击下一步

1.3 确认项目路径，确认完成点击finish

2、模拟三层创建包和类

2.1 创建service接口

package com.yuank.service;  
  
public interface IAccountService {  
    /** 
     * 模拟保存账户 
     */  
    void saveAccount();  
}  

2.2 创建service接口的实现类

package com.yuank.service.impl;  
  
import com.yuank.dao.IAccountDao;  
import com.yuank.dao.impl.AccountDaoImpl;  
import com.yuank.service.IAccountService;  
  
/** 
 * @author PC-Black 
 * @version v1.0 
 * @date 2019/7/21 21:33 
 * @description TODO 
 **/  
public class AccountServiceImpl implements IAccountService {  
    //手动初始化  
    private IAccountDao accountDao = new AccountDaoImpl();  
  
    public void saveAccount() {  
        accountDao.saveAccount();  
    }  
} 

2.3 创建dao持久层接口

package com.yuank.dao;  
  
public interface IAccountDao {  
    void saveAccount();  
}  

2.4 创建dao持久层实现类

package com.yuank.dao.impl;  
  
import com.yuank.dao.IAccountDao;  
  
/** 
 * @author PC-Black 
 * @version v1.0 
 * @date 2019/7/21 21:38 
 * @description TODO 
 **/  
public class AccountDaoImpl implements IAccountDao {  
  
    public void saveAccount() {  
        System.out.println("保存账户");  
    }  
}

2.5 创建web表现层

import com.yuank.service.IAccountService;  
import com.yuank.service.impl.AccountServiceImpl;  
/** 
 * @author PC-Black 
 * @version v1.0 
 * @date 2019/7/21 21:39 
 * @description TODO 
 **/  
public class Client {  
    public static void main(String[] args) {  
        IAccountService accountService = new AccountServiceImpl();  
        accountService.saveAccount();  
    }  
}

2.6 测试运行

3、创建配置文件

3.1 在resources下创建：applicationContext.xml

<?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">  
  
  
  
</beans>  

3.2 在pom文件中添加依赖，解决配置文件约束报红

<dependencies>  
    <!--IOC相关依赖-->  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-context</artifactId>  
        <version>5.0.6.RELEASE</version>  
    </dependency>  
</dependencies>  

3.3 通过spring的IOC来创建对象

<!--  
    1. spring会通过反射的方式创建对象，并将该对象以key和value的方式存入到IOC容器中。  
    2. bean标签的id就是key，value就是类的全路径  
    3. 通过bean标签将对象创建并存入到IOC容器的方式，我们可以称之为装配bean  
    4. 只要可以正常new出来的对象，都可以通过这种方式装配到IOC容器中  
-->  
  
<!--将service实现类装配到IOC容器中-->  
<bean id="accountService" class="com.yuank.service.impl.AccountServiceImpl"/>  
  
<!-- 将dao实现类装配到IOC容器中 -->  
<bean id="accountDao" class="com.yuank.dao.impl.AccountDaoImpl"/> 

3.4 加载applicationContext.xml配置文件&从spring的IOC容器中获取对象

package com.yuank.web;  
  
import com.yuank.dao.IAccountDao;  
import com.yuank.service.IAccountService;  
import org.springframework.context.ApplicationContext;  
import org.springframework.context.support.ClassPathXmlApplicationContext;  
  
/**  
 * @author PC-Black  
 * @version v1.0  
 * @date 2019/7/21 21:39  
 * @description TODO  
 **/  
public class Client {  
    public static void main(String[] args) {  
//        IAccountService accountService = new AccountServiceImpl();  
  
        //1. 加载配置文件  
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");  
        //2. 从容器中获取service  
        IAccountService accountService = (IAccountService) ac.getBean("accountService");  
        //2.1 打印accountService对象  
        System.out.println(accountService);  
        //3. 从容器中获取dao  
        IAccountDao accountDao = (IAccountDao) ac.getBean("accountDao");  
        //3.1 打印accountDao对象  
        System.out.println(accountDao);  
  
        accountService.saveAccount();  
  
  
    }  
} 

3.5 运行main方法

查看控制台，我们发现对象创建成功