集成Mybatis

 本文根据个人喜好记录“腾讯课堂”的《Java项目之Maven+SpringMVC+Spring+Mybatis+MySql消费查询系统》视频教程关键步骤信息，视频地址：https://ke.qq.com/course/193395

1. pom文件中添加依赖

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-tx</artifactId>
  <version>${spring.version}</version>
</dependency>

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-jdbc</artifactId>
  <version>${spring.version}</version>
</dependency>

<!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
<dependency>
  <groupId>com.mchange</groupId>
  <artifactId>c3p0</artifactId>
  <version>0.9.5.2</version>
</dependency>

<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>6.0.6</version>
</dependency>

<!-- mybatis核心包 -->
<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>${mybatis.version}</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis-spring</artifactId>
  <version>1.3.1</version>
</dependency>

  其中spring和mybatis的版本号如下：

<spring.version>4.3.11.RELEASE</spring.version>
<mybatis.version>3.4.5</mybatis.version>

2. 配置spring-context

<context:property-placeholder location="classpath:db.properties"/>
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="user" value="${jdbc.user}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager"/>

    <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sessionFactory"/>
        <property name="basePackage" value="com.pawn.vip.dao"/>
    </bean>

 其中 db.properties如下：

jdbc.url=jdbc:mysql://localhost:3306/vip?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.user=root
jdbc.password=root

 3. 类路径下创建mybatis-config.xml

<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

</configuration>

4. 编写测试

   4.1 数据库中添加测试表tbl_test_hello

   4.2 编写mapper class

public interface HelloMapper {

    public String select() ;
}

  4.3 编写mapper xml

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.pawn.vip.dao.HelloMapper">
    
    <select id="select" resultType="string">
        select text from tbl_test_hello limit 1
    </select>
    
</mapper>

  4.4 业务层进行引用

@Service
public class HelloService {

    @Autowired
    HelloMapper helloMapper ;

    public String getHelloString(){
        return helloMapper.select() ;
    }
}

    4.5 测试结果