SpringIOC扫描器

spring.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"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">


<!--        扫描器：bean对象统一管理
                1.设置扫描范围
                2.在需要实例化的JavaBean添加注解
                        dao：@Repository
                        service：@service
                        controller：@controller
                        其他：@Component
                3.需要注入时用注解@Resource/@Autowired
                -->
        <context:component-scan base-package="com.xxx"></context:component-scan>
</beans>

需要实例化的类UserService

package com.xxx.service;

import com.xxx.dao.Dao1;

import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
public class UserService {

    @Resource
    private Dao1 dao1;

    public void test(){
        System.out.println("US.test");

        dao1.test();
    }
}

public static void main( String[] args ) {
        ApplicationContext ac=new ClassPathXmlApplicationContext("spring.xml");
        /**
         * 要用小写首字母
         */
//        Dao1 dao1=(Dao1) ac.getBean("dao1");
//        dao1.test();

        UserService us=(UserService) ac.getBean("userService");
        us.test();



    }