Spring框架集成Mybatis

本例演示转账操作

• 准备数据库表t_act(账户表)
  
• 创建maven模块,引入依赖

  <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>6.1.8</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.29</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.16</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>3.0.3</version>
        <!--Mybatis-spring如果使用2.*版本会报错.-->
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.17</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>6.1.7</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.7</version>
        </dependency>
    </dependencies>

• pojo实体类

package com.powernode.bank.pojo;

public class Account {

    private String actno;
    private Double balance;

    /*public Account() {
    }*/

    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;
    }



    public Account(String actno, Double balance) {
        this.actno = actno;
        this.balance = balance;
    }

    @Override
    public String toString() {
        return "Account{" +
                "actno='" + actno + '\'' +
                ", balance=" + balance +
                '}';
    }
}

• 编写mapper接口

package com.powernode.bank.mapper;

import com.powernode.bank.pojo.Account;

import java.util.List;

public interface AccountMapper {
    //这就是Dao
    int insert(Account account);
    int deleteByActno(String  actno);
    int update(Account account);
    Account selectByActno(String actno);
    List<Account> selectAll();
}

• 编写Mapper配置文件,该配置文件需要和Mapper接口在同一个目录或在resource目录下创建和Mapper接口相同目录结构

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace绑定一个对应的Dao/Mapper接口-->
<mapper namespace="com.powernode.bank.mapper.AccountMapper">
    <insert id="insert">
        insert into t_act values(#{actno}, #{balance})
    </insert>


    <delete id="deleteByActno">
        delete from t_act where actno = #{actno}
    </delete>

    <update id="update">
        update t_act set balance = #{balance} where actno = #{actno}
    </update>

    <select id="selectByActno" resultType="com.powernode.bank.pojo.Account">
        select * from t_act where actno = #{actno}
    </select>
    <select id="selectAll" resultType="com.powernode.bank.pojo.Account">
        select * from t_act
    </select>
</mapper>

• 编写service接口和service接口实现类

package com.powernode.bank.service;

import com.powernode.bank.pojo.Account;

import java.util.List;

public interface AccountService {
    //开户
    int save(Account act);
    //销户
    int deleteByActno(String actno);
    //修改账户
    int modify(Account account);
    //查询账户
    Account getByActno(String actno);
    //获取所有账户
    List<Account> getAll();
    //转账
    void transfer(String fromActno, String toActno, double money);
}

package com.powernode.bank.service.impl;

import com.powernode.bank.mapper.AccountMapper;
import com.powernode.bank.pojo.Account;
import com.powernode.bank.service.AccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Transactional
@Service
public class AccountServiceImpl implements AccountService {

    @Autowired
    private AccountMapper accountMapper;

    @Override
    public int save(Account act) {
        return accountMapper.insert(act);
    }

    @Override
    public int deleteByActno(String actno) {
        return accountMapper.deleteByActno(actno);
    }

    @Override
    public int modify(Account account) {
        return accountMapper.update(account);
    }

    @Override
    public Account getByActno(String actno) {
        return accountMapper.selectByActno(actno);
    }

    @Override
    public List<Account> getAll() {
        return accountMapper.selectAll();
    }

    @Override
    public void transfer(String fromActno, String toActno, double money) {
        Account fromAccount = accountMapper.selectByActno(fromActno);
        if (fromAccount.getBalance()< money){
            throw new RuntimeException("余额不足");
        };
        Account toAct = accountMapper.selectByActno(toActno);
        fromAccount.setBalance(fromAccount.getBalance()-money);
        toAct.setBalance(toAct.getBalance()+money);
        int count = accountMapper.update(fromAccount);
        count += accountMapper.update(toAct);
        if (count != 2){
            throw new RuntimeException("转账失败");
        }
    }
}

• 编写jdbc.properties配置文件

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://192.168.1.41:3306/test
jdbc.username=root
jdbc.password=*********

• 编写mybatis-config.xml配置文件

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

• 编写spring.xml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.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!--组件扫描-->
    <context:component-scan base-package="com.powernode.bank"/>

    <!--引入外部数据源-->
    <context:property-placeholder location="jdbc.properties"/>

    <!--数据源-->
    <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="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--SqlSessionFactoryBean-->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--注入数据源-->
        <property name="dataSource" ref="dataSource"/>
        <!--指定mybatis核心配置文件-->
        <property name="configLocation" value="mybatis-config.xml"/>
        <!--指定别名-->
        <property name="typeAliasesPackage" value="com.powernode.bank.pojo"/>
    </bean>

    <!--Mapper扫描配置器,主要扫描Mapper接口,生成代理类-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.powernode.bank.mapper"/>
    </bean>

    <!--事务管理器-->
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--启用事务注解-->
    <tx:annotation-driven transaction-manager="txManager"/>
</beans>

• 测试

public class SMTest {
    @Test
    public void testSM(){
        ClassPathXmlApplicationContext classPathXmlApplicationContext = new ClassPathXmlApplicationContext("spring.xml");
        AccountService accountServiceImpl = classPathXmlApplicationContext.getBean("accountServiceImpl", AccountService.class);
        try{
            accountServiceImpl.transfer("act-001","act-002", 10000);
            System.out.println("转账成功");
        }catch(Exception e){
            e.printStackTrace();
        }

    }