环境搭建

pom.xml

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.18.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.1.18.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.6</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.5</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
    </dependencies>

    <build>
        <resources>
            <resource>
                <directory>src/main/resource</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

实体类

@Data
public class User {
    private int id;
    private String name;
    private String pwd;
}

mapper

public interface UserMapper {
    List<User> selectUser();
}

<?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.starry.mapper.UserMapper">
    <select id="selectUser" resultType="user">
        select * from mybatis.user
    </select>
</mapper>

mybatis-config.xml

<?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>


    <typeAliases>
        <package name="com.starry.pojo"></package>
    </typeAliases>


</configuration>

spring-mybatis.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
">


    <!--dataSource 使用spring的配置来替换mybatis的配置
    使用spring提供的jdbc
    -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncode=UTF-8"></property>
        <property name="username" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <!--可以绑定mybatis的配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"></property>
        <property name="mapperLocations" value="classpath:com/starry/mapper/*.xml"></property>
    </bean>

    <!--sqlSessionTemplate 就是之前使用的sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--使用构造器注入sqlSessionFactory-->
        <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"></constructor-arg>
    </bean>

</beans>

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
">


    <import resource="spring-mybatis.xml"></import>


    <bean id="userMapper" class="com.starry.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"></property>
    </bean>
</beans>

实现一

userMapperImpl

public class UserMapperImpl implements UserMapper {

    //SqlSessionTemplate相当于mybatis的SqlSession
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

    public List<User> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

测试

@Test
public void test() throws IOException {
    ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
    List<User> userList = userMapper.selectUser();
    for (User user : userList) {
        System.out.println(user);
    }

}

1. 编写数据源
2. sqlSessionFactoryBean
3. sqlSessionTemplate
4. 创建实现类
5. 测试

实现二

UserMapperImpl2

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {


    public List<User> selectUser() {
        SqlSession sqlSession = getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

applicationContext.xml

<bean id="userMapper2" class="com.starry.mapper.UserMapperImpl2">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>

测试

@Test
public void test() throws IOException {
    ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    UserMapper userMapper = context.getBean("userMapper2", UserMapper.class);
    List<User> userList = userMapper.selectUser();
    for (User user : userList) {
        System.out.println(user);
    }

}

使用SqlSessionDaoSupport可以不用在bean中配置sqlSessionTemplate,但是需要在实现类中注入sqlSessionFactory

1. 编写数据源
2. sqlSessionFactoryBean
3. 创建实现类
4. 测试