实现步骤

一，引入依赖

<!--仓库--><repositories><!--spring里程碑版本的仓库--><repository><id>repository.spring.milestone</id><name>Spring Milestone Repository</name><url>https://repo.spring.io/milestone</url></repository></repositories><dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>6.0.0-M2</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>6.0.0-M2</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.8</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.11</version></dependency><!--        这里版本不能随意选，选2.0.7这个不会出问题--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.7</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.2.13</version></dependency><!--        spring对Junit的支持--><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>6.0.0-M2</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.2</version><scope>test</scope></dependency>
<!--        使用Resource需要的依赖--><dependency><groupId>jakarta.annotation</groupId><artifactId>jakarta.annotation-api</artifactId><version>2.1.1</version></dependency></dependencies>

二，基于三层架构，准备所有的包和类

bean层（Account类）

package com.hkd.spring6.bean;public class Account {private String actno;private Double balance;public Account() {}public Account(String actno, Double balance) {this.actno = actno;this.balance = balance;}public String getActno() {return actno;}public void setActno(String actno) {this.actno = actno;}public Double getBalance() {return balance;}public void setBalance(Double balance) {this.balance = balance;}@Overridepublic String toString() {return "Account{" +"actno='" + actno + '\'' +", balance=" + balance +'}';}
}

service层

接口

package com.hkd.spring6.service;public interface ActService {void transfer(String fromAct, String toAct, double money);
}

实现类

package com.hkd.spring6.service.impl;import com.hkd.spring6.bean.Account;
import com.hkd.spring6.mapper.ActMapper;
import com.hkd.spring6.service.ActService;
import jakarta.annotation.Resource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;@Service("actService")
@Transactional
public class ActServiceImpl implements ActService {//    @Autowired
//    private ActMapper actMapper;//    MyBatis为mapper接口自动生成的实现类类名是mapper类首字母小写@Resource(name = "actMapper")private ActMapper actMapper;@Overridepublic void transfer(String fromAct, String toAct, double money) {Account select1 = actMapper.select(fromAct);if (select1.getBalance() < money) {throw new RuntimeException("余额不足");}Account select2 = actMapper.select(toAct);select1.setBalance(select1.getBalance() -money);select2.setBalance(select2.getBalance() + money);int update = actMapper.update(select1);update += actMapper.update(select2);if (update != 2) {throw new RuntimeException("转账失败");}}
}

mapper层

接口

package com.hkd.spring6.mapper;import com.hkd.spring6.bean.Account;public interface ActMapper {Account select(String actno);int update(Account account);
}

sql映射文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.hkd.spring6.mapper.ActMapper"><select id="select" resultType="Account">select * from t_bank where actno = #{actno}</select><update id="update">update t_bank set balance = #{balance} where actno = #{actno}</update>
</mapper>

三，配置文件的完成

1.jdbc.properties（数据库相关配置文件）

jdbc.driver = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://localhost:3306/mybatis
jdbc.user = root
jdbc.password = hsp

2.MyBatis核心配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><settings>
<!--        开启日志打印--><setting name="logImpl" value="STDOUT_LOGGING"/></settings>
</configuration>

3.Spring配置文件

<?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"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"><context:component-scan base-package="com.hkd.spring6"/><context:property-placeholder location="jdbc.properties"/><bean id="datasource" class="com.alibaba.druid.pool.DruidDataSource"><property name="driverClassName" value="${jdbc.driver}"/><property name="url" value="${jdbc.url}"/><property name="username" value="${jdbc.user}"/><property name="password" value="${jdbc.password}"/></bean><bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="datasource"/></bean><tx:annotation-driven transaction-manager="transactionManager"/><bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"><property name="dataSource" ref="datasource"/></bean><bean class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="datasource"/><property name="typeAliasesPackage" value="com.hkd.spring6.bean"/><property name="configLocation" value="mybatis-config.xml"/></bean><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.hkd.spring6.mapper"/></bean></beans>

四，测试代码

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring.xml")
public class TestSm {@Autowiredprivate ActService actService;@Testpublic void testSm(){try {actService.transfer("act-001","act-002",1);System.out.println("转账成功");} catch (Exception e){System.out.println("转账失败");e.printStackTrace();}}
}