spring-整合mybatis

1 引入依赖

1.1 junit (非必须)

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>

1.2 lombok (非必须)

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.20</version>
</dependency>

1.3 mysql (必须)

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.47</version>
</dependency>

1.4 mybatis (必须)

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.2</version>
</dependency>

1.5 spring相关的 (必须)

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>5.2.0.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.1.9.RELEASE</version>
</dependency>

1.6 aspectJ AOP (必须)

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

1.7 mybatis-spring 整合包 (必须)

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.2</version>
</dependency>

1.8 配置Maven静态资源过滤问题

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

2 编写pojo实体类

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

3 编写UserMapper接口

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

3 编写对应的 UserMapper.xml 文件

<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.lv.mapper.UserMapper">
    <select id="selectUser" resultType="user">
        select * from user
    </select>
</mapper>

4 编写mybatis的配置文件

<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases>
        <package name="com.lv.pojo"/>
    </typeAliases>
</configuration>

5 编写spring配置文件 (重点)

<?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的数据源替换Mybatis的配置 c3p0 dbcp druid
    我们这里使用Spring提供的JDBC:org.springframework.jdbc.datasource
    -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?createDatabaseIfNotExist=true&amp;useSSL=false"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>
    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--绑定mybatis配置文件,mybatis配置文件中的东西,都可以在这里配置-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/lv/mapper/*.xml"/>
    </bean>
    <!--SqlSessionTemplate:就是我们使用的SqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入sqlSessionFactory,因为它没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>
</beans>

6 编写UserMapper接口的实现类

public class UserMapperImpl implements UserMapper{
    //我们所有的操作,都使用sqlSession来执行,在原来,我们都使用SqlSessionTemplate;
    private SqlSessionTemplate sqlSession;
    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }
    @Override
    public List<User> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

7 编写最终的spring配置文件 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-dao.xml"/>
 
    <bean id="userMapper" class="com.lv.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>
</beans>

8 测试

@Test
public void test() {
    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);
    }
}

9 执行结果

10 第二种方式

10.1 修改UserMapper实现类

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
    @Override
    public List<User> selectUser() {
        return getSqlSession().getMapper(UserMapper.class).selectUser();
    }
}

10.2 在applicationContext.xml 中修改Bean的配置

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

10.3 测试

测试代码和执行结果不变