整合 Mybatis-Spring方式二（SqlSessionDaoSupport方式）

SqlSession

在 MyBatis 中，你可以使用 SqlSessionFactory 来创建 SqlSession。一旦你获得一个 session 之后，你可
以使用它来执行映射了的语句，提交或回滚连接，最后，当不再需要它的时候，你可以关闭 session。使
用 MyBatis-Spring 之后，你不再需要直接使用 SqlSessionFactory 了，因为你的 bean 可以被注入一个线
程安全的 SqlSession，它能基于 Spring 的事务配置来自动提交、回滚、关闭 session。

SqlSessionDaoSupport

SqlSessionDaoSupport 是一个抽象的支持类，用来为你提供 SqlSession。调用 getSqlSession() 方法你会
得到一个 SqlSessionTemplate，之后可以用于执行 SQL 方法。

案例

导包

<dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
    </dependency>
    <!--连接数据库-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.17</version>
    </dependency>
    <!--使用mybatis框架-->
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.2</version>
    </dependency>
    <!-- 直接导入spring-webmvc会自动帮我们导入spring-aop，spring-beans，
            spring-context，spring-core，spring-expression，spring-web的依赖jar包 -->
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.3.3.RELEASE</version>
    </dependency>
    <!-- 配置声明式事务 -->
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.3.3.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.10</version>
    </dependency>
    <!-- spring-mybatis -->
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring Spring整合Mybatis需要的整合包 -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.2</version>
    </dependency>
	<dependency>
		<groupId>org.projectlombok</groupId>
		<artifactId>lombok</artifactId>
		<version>1.16.20</version>
		<scope>provided</scope>
	</dependency>

1.User

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

}

2.UserMapper

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

3.UserMapper.xml

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

4.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.tt.pojo"/>
    </typeAliases>

</configuration>

5.spring-dao.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"
       xmlns:aop="http://www.springframework.org/schema/aop" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
       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/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd">

    <!--DataSource:使用Spring的数据源替换Mybatis的配置c3pe 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?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf-8&amp;autoReconnect=true"/>
        <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Mabatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/tt/mapper/*.xml"/>
    </bean>
</beans>

6.UserMapperImpl2

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

7.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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       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">

    <import resource="spring-dao.xml"/>
    <!---->
    <bean id="userMapper" class="com.tt.mapper.UserMapperImpl" >
        <property name="sqlSessionFactory" ref= "sqlSessionFactory" />
    </bean>

</beans>

8.MyTest

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