pom.xml:
            
            
              XML
              
              
            
          
          <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>6.0.12</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.19</version>
        </dependency>
    </dependencies>applicationContext.xml:
            
            
              XML
              
              
            
          
          <?xml version="1.0" encoding="UTF-8"?>
<!--1、注意:要导入schema约束-->
<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
                           http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
    <!--扫描哪个包下的文件-->
    <context:component-scan base-package="com.by"></context:component-scan>
    <!--加载config.properties-->
    <context:property-placeholder location="config.properties"></context:property-placeholder>
</beans>log4j.properties:
            
            
              XML
              
              
            
          
          # Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%nconfig.porperties:
            
            
              XML
              
              
            
          
          name=小王
age=18UserDaoImpl:
            
            
              java
              
              
            
          
          package com.by.dao;
import org.springframework.stereotype.Repository;
/**
 * 持久层实现类
 */
//@Repository("userDao")
@Repository //不配置默认为类名首字母小写
public class UserDaoImpl implements UserDao {
    @Override
    public void addUser() {
        System.out.println("insert into tb_user......");
    }
}UserServiceImpl:
            
            
              java
              
              
            
          
          package com.by.service;
import com.by.dao.UserDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.ImportResource;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
/**
 * 业务层实现类
 */
//@Service("userService")
@Service //不配置默认为类名首字母小写
//@Component
@Scope("prototype")
public class UserServiceImpl implements UserService {
    @Autowired //注入属性
    private UserDao userDao;
    @Value("${name}")
    private String name;
    @Value("${age}")
    private Integer age;
    @Override
    public void addUser() {
        System.out.println(userDao + "--" + name + "__" + age);
        userDao.addUser();
    }
}总结:
IOC:
1.@Service:用于service层,@Service("userService")指定配置的id,@Service //不配置默认为类名首字母小写。
2.@Repository:用于dao层,@Repository("userDao")指定配置的id,@Repository //不配置默认为类名首字母小写。
3.@Component:用于配置与三层架构之外的类,也可用于其它几层,使用方法同上。
4.@Scope:用于配置bean的作用域范围,使用方法:@Scope("prototype")
DI:
1.@Autowired:用于注入属性,
@Autowired //注入属性
private UserDao userDao;
2.@Resource(name="userDao"),主要用于自定义类型
@Autowired //注入属性
private UserDao userDao;3.@value("${}"),主要用于基本数据类型和String类型,需要在config.properties文件中声明属性,在applicationContext.xml文件中加载config.properties文件
@Value("${name}")
private String name;