Spring IoC 入门案例步骤

步骤

1. 导入 Spring 坐标

   <!-- pom.xml文件，配置maven环境 -->
   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-context</artifactId>
       <version>5.2.10.RELEASE</version>
   </dependency>
   

2. 定义 Spring 管理的类（接口）

   public interface BookService {
       public void save();
   }
   

   public class BookServiceImpl implements BookService {
       private BookDao bookDao = new BookDaoImpl();
   
       @Override
       public void save() {
           System.out.println("book service save...");
           bookDao.save();
       }
   }
   

3. 创建 Spring 配置文件，配置对应类作为 Spring 管理的 bean

   <!-- 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">
   
       <bean id="bookDao" class="com.bellongyan.dao.impl.BookDaoImpl"/>
       <bean id="bookService" class="com.bellongyan.service.impl.BookServiceImpl"/>
   
   </beans>
   

4. 初始化 IoC 容器（Spring核心容器/Spring容器），通过容器获取 bean

   public class App2 {
       public static void main(String[] args) {
   //        获取IOC容器
           ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
   
   //        获取bean
           BookDao bookDao = (BookDao) ctx.getBean("bookDao");
           bookDao.save();
   
           BookService bookService = (BookService) ctx.getBean("bookService");
           bookService.save();
   
       }
   }