MyBatis-Spring(一):整合Mybatis与Spring方式一:SqlSessionTemplate

MyBatis-Spring 会帮助你将 MyBatis 代码无缝地整合到 Spring 中。它将允许 MyBatis 参与到 Spring 的事务管理之中，创建映射器 mapper 和 SqlSession 并注入到 bean 中，以及将 Mybatis 的异常转换为 Spring 的 DataAccessException。

1. 准备工作,实体类，mapper接口，mybatis配置文件

public class User {
    private int id;
    private String username;
    private String password;
}

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

<mapper namespace="com.spring.mapper.UserMapper">
    <select id="selectUser" resultType="user">select * from databasename.user;</select>
</mapper>

<!--mybatis-config.xml配置文件-->
<configuration>
    <typeAliases>
        <package name="com.spring.pojo"/>
    </typeAliases>
</configuration>

2. 编写数据源配置

    <!--DataSource：使用Spring的数据源替换Mybatis的配置 c3p0 dbcp druid
    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 name="url" value="jdbc:mysql://localhost:3306/databasename?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value=""/>
    </bean>
    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--绑定Mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/spring/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，因为他没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

4. sqlSessionFactory

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

5. sqlSessionTemplate

<!--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，因为他没有set方法-->
    <constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

6. 需要给接口加实现类

public class UserMapperImpl implements UserMapper { 

    private SqlSessionTemplate sqlSession;	
    public void setSqlSession(SqlSessionTemplate sqlSession) {
		this.sqlSession = sqlSession;
	}
	public List<User> selectUser() {
		UserMapper mapper = sqlSession.getMapper(UserMapper.class);
		return mapper.selectUser();
	}
}

7. 将自己写的实现类，注入到Spring中

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

8. 测试

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }
    }
}

9. 项目依赖

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.48</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.4.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.4</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
    </dependencies>

来源：oschina

链接：https://my.oschina.net/u/4087795/blog/3213829