Java框架spring Boot学习笔记：bean管理（注解和配置文件混合使用）

Posted 2020-10-13 pyqb

配置文件和注解混合使用

• 创建对象操作使用配置文件方式实现
• 注入属性的操作使用注解方式实现

 

编写BookDao.java和OrderDao.java文件

BookDao.java

1 package com.example.spring;
2 
3 public class BookDao {
4     public void book(){
5         System.out.println("Book Dao.");
6     }
7 }

OrderDao.java

1 package com.example.spring;
2 
3 public class OrderDao {
4     public void order(){
5         System.out.println("Order Dao.");
6     }
7 }

 

创建对象操作使用配置文件方式实现

编写配置文件Beans.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4        xmlns:context="http://www.springframework.org/schema/context"
 5        xsi:schemaLocation="http://www.springframework.org/schema/beans
 6     http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
 7     http://www.springframework.org/schema/context
 8     http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 9 
10     <!--开启注解扫描，到包里面扫描类、方法、属性上面是否有注解-->
11     <context:component-scan base-package="com.example.spring"></context:component-scan>
12 
13     <!-- 在配置文件中创建对象 -->
14     <bean id="bookService" class="com.example.spring.BookService"></bean>
15     <bean id="bookDao" class="com.example.spring.BookDao"></bean>
16     <bean id="orderDao" class="com.example.spring.OrderDao"></bean>
17 
18 </beans>

 

注入属性的操作使用注解方式实现

编写BookService.java

 1 package com.example.spring;
 2 
 3 import javax.annotation.Resource;
 4 
 5 public class BookService {
 6     //注解方式注入属性，得到对象
 7     @Resource(name = "bookDao")
 8     private BookDao bookDao;
 9 
10     @Resource(name = "orderDao")
11     private OrderDao orderDao;
12 
13     public void service(){
14         System.out.println("Book Service.");
15         //调用方法
16         bookDao.book();
17         orderDao.order();
18     }
19 }

 

编写Application.java

 1 package com.example.spring;
 2 
 3 import org.springframework.context.support.AbstractApplicationContext;
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 public class Application {
 7     public static void main(String[] args) {
 8         //bean配置文件所在位置 D:\\IdeaProjects\\spring\\src\\Beans.xml
 9         //使用AbstractApplicationContext容器
10         AbstractApplicationContext context = new ClassPathXmlApplicationContext("file:D:\\IdeaProjects\\spring\\src\\Beans.xml");
11         //得到配置创建的对象
12         BookService bookService = (BookService) context.getBean("bookService");
13         bookService.service();
14     }
15 }

运行输出

Book Service.
Book Dao.
Order Dao.