Mybatis和Mybatis Plus学习之旅(2022-12-04)

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wx6383079ed5367 2022-12-04 20:51:13 ©著作权

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MyBatis和Spring的结合

配置文件

applicationContext.xml（spring的配置文件）

<?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:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.2.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring.xsd">
    
    <!--    启用注解扫描，并设置扫描的路径-->
    <context:component-scan base-package="com.demo.mybatis"/>
    
    <!--    引入数据库配置-->
    <context:property-placeholder location="classpath:dbConfig.properties"/>
    
    <!--    配置数据库连接池-->
    <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>
    
    <!--    使用spring管理数据库的事务-->
    <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="datasource"/>
    </bean>
    
    <!--设置事务管理器-->
    <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>
    <!--数据库会话工厂类，创建数据库会话-->
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--        数据库连接池-->
        <property name="dataSource" ref="datasource"/>
        <!--        mybatis配置文件的路径-->
        <property name="configLocation" value="classpath:myBatis-config.xml"/>
        <!--        myBatis映射文件的路径-->
        <property name="mapperLocations" value="classpath:mybatis/mapper/*.xml"/>
    </bean>
    
    <!--    数据库会话模板，由工厂类创建-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
        <constructor-arg name="executorType" value="BATCH"></constructor-arg>
    </bean>
   
    <!--    Mapper接口扫描-->
    <mybatis-spring:scan base-package="com.demo.mybatis.dao"/>
</beans>

dbConfig.properties(数据库的配置文件)

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://192.168.56.10:3306/my_test?allowMultiQueries=true
jdbc.user=root
jdbc.password=root

myBatis-config.xml（mybatis的配置文件）

<?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>
<!--    <environments default="development">-->
<!--        <environment id="development">-->
<!--            <transactionManager type="JDBC"/>-->
<!--            <dataSource type="POOLED">-->
<!--                <property name="driver" value="${driver}"/>-->
<!--                <property name="url" value="${url}"/>-->
<!--                <property name="username" value="${username}"/>-->
<!--                <property name="password" value="${password}"/>-->
<!--            </dataSource>-->
<!--        </environment>-->
<!--    </environments>-->
<!--    <mappers>-->
<!--        <mapper resource="org/mybatis/example/BlogMapper.xml"/>-->
<!--    </mappers>-->
</configuration>

EmployeeMapper.xml（业务SQL编写的配置）

<?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">
<!--对应的service-->
<mapper namespace="com.demo.mybatis.dao.EmployeeMapper">
<!--    对应service里面的方法-->
    <select id="getEmpById" resultType="com.demo.mybatis.bean.Employee">
        select * from tbl_employee where id=#{id};
    </select>
</mapper>

POM文件

<?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>org.example</groupId>
    <artifactId>MybatisAndMybatisPlus</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>3.1.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.23</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.4</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.10</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.7</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.18</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.6</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
    </dependencies>

</project>

目录结构

Mybatis和Mybatis Plus学习之旅(2022-12-04)_spring

单元测试注意点

普通的单元测试无法获取Spring容器中的bean，有两种方式

import com.demo.mybatis.bean.Employee;
import com.demo.mybatis.service.EmployeeService;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cglib.core.Local;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

//方式一
@ContextConfiguration(locations={"classpath:applicationContext.xml"})
@RunWith(SpringJUnit4ClassRunner.class)
public class EmployeeTest {
    @Autowired
    private EmployeeService employeeService;
    public void testGetEmp(){
//        方式二
//        ApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
//        employeeService = (EmployeeService)context.getBean(EmployeeService.class);
        Employee emp = this.employeeService.getEmp(1);
        System.out.println(emp.toString());

    }
}