Spring - 快速入门代码实现

• 1. Spring 的开发步骤
• 2. 代码实现

1. 导入坐标
2. 创建 Bean
3. 创建 applicationContext.xml
4. 在配置文件中进行配置
5. 创建 ApplicationContext 对象 getBean

目录结构：

pom.xml 文件：

    4.0.0
    war

    com.itheima
    itheima_spring_ioc
    1.0-SNAPSHOT

    
        
            org.springframework
            spring-context
            5.0.5.RELEASE
        
    

    
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                3.6.1
                
                    13
                    13
                
            
        
    

UserDao：

package com.itheima.dao;

public interface UserDao {
    public void save();
}

UserDaoImpl：

package com.itheima.dao.impl;

import com.itheima.dao.UserDao;

public class UserDaoImpl implements UserDao {
    public void save() {
        System.out.println("save running...");
    }
}

applicationContext.xml：

UserDaoDemo：

package com.itheima.damo;

import com.itheima.dao.UserDao;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UserDaoDemo {
    public static void main(String[] args){
        ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserDao userDao = (UserDao) app.getBean("userDao");
        userDao.save();
    }
}