【Spring6】| Spring6 integrates MyBatis3.5

Table of contents

One: Spring6 integrates MyBatis3.5

Step 1: Prepare the database table

Step 2: Create a module in IDEA and introduce dependencies

Step 3: Realize based on the three-tier architecture, so create all packages in advance

Step 4: Write pojo

Step 5: Write mapper interface

Step 6: Write mapper configuration file

Step 7: Write service interface and service interface implementation class

Step 8: Write the jdbc.properties configuration file

Step 9: Write the mybatis-config.xml configuration file

Step 10: Write the spring.xml configuration file

Step 11: Write a test program, add transactions, and test 

Supplement: import of Spring configuration file

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One: Spring6 integrates MyBatis3.5

Step 1: Prepare the database table

• Use the t_act table (account table)

 

Step 2: Create a module in IDEA and introduce dependencies

• spring-context
• spring-jdbc
• mysql driver
• my shoe
• mybatis-spring: The dependency provided by mybatis to integrate with the spring framework
• druid connection pool
• junit

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.bjpowernode</groupId>
    <artifactId>spring6-015-sm</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <!--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>
        <!--spring context依赖-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>6.0.0-M2</version>
        </dependency>
        <!--spring-jdbc依赖-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>6.0.0-M2</version>
        </dependency>
        <!--mysql驱动依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.30</version>
        </dependency>
        <!--mybatis依赖-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.10</version>
        </dependency>
        <!--mybatis提供的与spring框架集成的依赖-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.1</version>
        </dependency>
        <!--druid连接池依赖-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.13</version>
        </dependency>
        <!--junit依赖-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>

</project>

Step 3: Realize based on the three-tier architecture, so create all packages in advance

• com.powernode.bank.mapper
• com.powernode.bank.service
• com.powernode.bank.service.impl
• com.powernode.bank.pojo

Step 4: Write pojo

• Account, property privatization, provides public setter getter and toString.

package com.powernode.bank.pojo;

public class Account {
    private String actno;
    private Double balance;

    public Account() {
    }

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

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

Step 5: Write mapper interface

AccountMapper interface, define method

package com.powernode.bank.mapper;

import com.powernode.bank.pojo.Account;

import java.util.List;

// 连接接口的实现类不需要写，采用Mybatis动态代理机制生成实现类
public interface AccountMapper {
    // 增
    int insert(Account account);
    // 删
    int deleteByActno(String actno);
    // 改
    int update(Account account);
    // 查一个
    Account selectByActno(String actno);
    // 查所有
    List<Account> selectAll();

}

Step 6: Write mapper configuration file

Configure the namespace and the sql corresponding to each method in the configuration file.

Note 1: Create this directory according to the prompt in the figure below. Note that the slash is not a dot; create a new one under the resources directory, and it must correspond to the Mapper interface package.

Note 2: If the interface is called AccountMapper, the configuration file must be AccountMapper.xml; and the name of the namespace namespace must be the fully qualified name of the interface AccountMapper

<?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">
<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="Account">
        select * from t_act where actno = #{actno}
    </select>
    <select id="selectAll" resultType="Account">
        select * from t_act
    </select>
</mapper>

Step 7: Write service interface and service interface implementation class

AccountService interface class

package com.powernode.bank.service;

import com.powernode.bank.pojo.Account;

import java.util.List;

public interface AccountService {
    // 开户
    int save(Account act);
    // 根据账号销户
    int deleteByActno(String actno);
    // 修改账户
    int update(Account act);
    // 根据账号获取账户
    Account getByActno(String actno);
    // 获取所有账户
    List<Account> getAll();
    // 转账
    void transfer(String fromActno, String toActno, double money);
}

AccountServiceImpl implementation class, injected into AccountMapper, and incorporated into Spring container management

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 // 添加事务管理
@Service("accountService") // 纳入Spring容器管理
public class AccountServiceImpl implements AccountService {

    @Autowired// 注入AccountMapper
    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 update(Account act) {
        return accountMapper.update(act);
    }

    @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) {
        // 先查询第一个账户的余额
        Account fromAccount = accountMapper.selectByActno(fromActno);
        if (fromAccount.getBalance() < money){
            throw new RuntimeException("余额不足！");
        }
        // 余额充足
        Account toAccount = accountMapper.selectByActno(toActno);
        // 修改内存中的余额
        fromAccount.setBalance(fromAccount.getBalance()-money);
        toAccount.setBalance(toAccount.getBalance()+money);
        // 修改数据库中的数据
        int count = accountMapper.update(fromAccount);
        count += accountMapper.update(toAccount);
        // 判断转账是否成功
        if (count != 2) {
            throw new RuntimeException("转账失败！");
        }


    }
}

Step 8: Write the jdbc.properties configuration file

Database connection pool related information

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring
jdbc.username=root
jdbc.password=123

Step 9: Write the mybatis-config.xml configuration file

This file can be omitted, and most of the configuration can be transferred to the spring configuration file!

If you encounter system-level configuration related to mybatis, you still need this file, and only log information is configured here!

<?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>
    <!--打印mybatis的日志信息、sql语句等信息-->
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
</configuration>

Step 10: Write the spring.xml configuration file

• component scan
• import external properties file
• data source
• SqlSessionFactoryBean configuration
  • Inject mybatis core configuration file path
  • Inject data source
  • Specify an alias package
• Mapper scan configurator
  • Packages to scan
• Transaction Manager DataSourceTransactionManager
  • Inject data source
• Enable transaction annotations
  • inject transaction manager

Note: When you directly write tag content in the spring.xml file, IDEA will automatically add a namespace for you

<?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"/>

    <!--引入外部的属性配置文件-->
    <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>

    <!--配置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>

Step 11: Write a test program, add transactions, and test 

package com.powernode.bank.test;

import com.powernode.bank.service.AccountService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SMTest {
    @Test
    public void testSM(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");
        AccountService accountService = applicationContext.getBean("accountService", AccountService.class);
        try {
            accountService.transfer("act-001","act-002",1000);
            System.out.println("转账成功");
        }catch (Exception e){
            e.printStackTrace();
        }

    }
}

Supplement: import of Spring configuration file

There are multiple spring configuration files, and import can be used in the spring core configuration file. We can define component scanning separately in a configuration file, as follows:

common.xml: Write a separate configuration file, which defines the information scanned by the component

<?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 http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

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

</beans>

Introduced in the core configuration file spring.xm:

<?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">

    <!--引入其他的spring配置文件-->
    <import resource="common.xml"/>

</beans>

Note: In actual development, service is configured separately in a file, dao is configured separately in a file, and then introduced in the core configuration file, so develop a good habit!