最新Spring整合MyBatis详细步骤

1.创建maven工程

项目总体部署

2.部署MyBatis框架

2.1 添加mybatis依赖

<!-- MyBatis依赖 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.27</version>
</dependency>

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.7</version>
</dependency>

2.2 新建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>

</configuration>

2.3 添加Lombok、junit依赖

<dependency>
<groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.22</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.1</version>
    <scope>test</scope>
</dependency>

3.部署Spring框架

3.1添加依赖

<!-- Spring依赖 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.18</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>5.3.18</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.18</version>
        </dependency>

3.2 创建applicationContext.xml配置文件

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
        https://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/aop 
         https://www.springframework.org/schema/aop/spring-aop.xsd
         http://www.springframework.org/schema/context
         https://www.springframework.org/schema/context/spring-context.xsd">

</beans>

4.添加Spring整合MyBatis的依赖*

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

5.配置数据源（Druid）

5.1 添加druid依赖

<!-- druid依赖 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.8</version>
</dependency>

5.2 创建druid.properties文件

druid.driver=com.mysql.cj.jdbc.Driver
druid.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
druid.username=root
druid.password=root

## 连接池参数
druid.pool.init=1
druid.pool.minIdle=3
druid.pool.maxActive=20
druid.pool.maxWait=30000

5.3 在Spring配置文件中配置DruidDataSource

 <!--加载druid.properties文件-->
 <context:property-placeholder location="classpath:druid.properties"/>
 <!--数据源DataSource的创建-->
 <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
     <property name="driverClassName" value="${druid.driver}"/>
     <property name="url" value="${druid.url}"/>
     <property name="username" value="${druid.username}"/>
     <property name="password" value="${druid.password}"/>

     <property name="initialSize" value="${druid.pool.init}"/>
     <property name="minIdle" value="${druid.pool.minIdle}"/>
     <property name="maxActive" value="${druid.pool.maxActive}"/>
     <property name="maxWait" value="${druid.pool.maxWait}"/>
 </bean>

6.创建SqlSessionFactory

<!--MyBatis的SqlSessionFactory对象的创建-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!--配置数据源-->
    <property name="dataSource" ref="dataSource"/>
    <!--配置Mapper文件路径-->
    <property name="mapperLocations" value="classpath:mappers/*Mapper.xml"/>
    <!--配置需要定义别名的实体类的包-->
    <property name="typeAliasesPackage" value="com.gyh.pojo"/>
    <!--配置MyBatis的配置文件-->
    <property name="configLocation" value="classpath:mybatis-config.xml"/>
</bean>

7. 创建Mapper

<!--加载dao包中的所有接口，通过sqlSessionFactory获取sqlSession对象，然后创建所有的dao接口并存储在Spring容器中-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.gyh.dao"/>
    </bean>

8.使用示例

8.1创建一个user表并插入几条数据

id设置为自动递增

8.2 创建一个User类

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {

    private int userId;
    private String userName;
    private String userPwd; 

}

8.3 创建一个接口

在该接口中声明一个查询user的方法

public interface UserDao {

    public List<User> selectUser();
}

8.4 创建UserMapper.xml文件

namespace绑定UserDao接口，编写sql语句时id要与接口中的方法名一致。
当namespace绑定接口后，就可以不用写接口实现类，Mybatis就会通过该绑定自动找到对应要执行的SQL语句。

<?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.gyh.dao.UserDao">

    <resultMap id="userMap" type="User">
        <id column="id" property="userId"/>
        <result column="username" property="userName"/>
        <result column="password" property="userPwd"/>

    </resultMap>

    <select id="selectUser" resultMap="userMap">
        select * from user
    </select>
</mapper>

8.5 编写测试类

@Test
public void selectUsersTest(){
    ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    //UserDao userDao = context.getBean("userDao", UserDao.class);
    UserDao userDao = (UserDao) context.getBean("userDao");
    List<User> users = userDao.selectUser();
    for (User user:users) {
        System.out.println(user);
    }
}