spring--整合mybatis

步骤

1.导入相关jar包

• junit
• mybatis
• mysql
• spring相关
• aop
• spring-mybatis
• spring-jdbc

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.21</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.6</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.16</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <!--spring操作数据库需要导入springjdbc包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.16</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.8</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>

• 编写数据源配置

    <!--DataSource:使用spring的数据源替代Mybatis的配置c3p0 dbcp druid-->
    <!--我们这里使用Spring提供的JDBC：org.springframework.jdbc.datasource.DriverManagerDataSource-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf8&amp;useSSL=false&amp;serverTimezone=UTC&amp;rewriteBatchedStatements=true"/>
        <property name="username" value="root"/>
        <property name="password" value="qq2420582566"/>
    </bean>

• sqlSessionFactory

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

• sqlSessionTemplate

<!--SqlSessionTemplate:就是我们使用的sqlSession-->
    <bean id="SqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入的方法，因为它没有set方法-->
        <constructor-arg ref="sqlSessionFactory"/>
    </bean>

• 给接口加实现类

public class UserMapperImpl implements UserMapper {

    //我们所有的操作，都是使用SQLSession来执行，现在都使用SQLSessionTemplate来执行；
    private SqlSessionTemplate sqlSessionTemplate;

    public UserMapperImpl(SqlSessionTemplate sqlSessionTemplate) {
        this.sqlSessionTemplate = sqlSessionTemplate;
    }

    @Override
    public List<User> selectUser() {
        UserMapper mapper = sqlSessionTemplate.getMapper(UserMapper.class);
        List<User> users = mapper.selectUser();
        return users;
    }
}

<bean id="userMapperImpl" class="com.yf.mapper.UserMapperImpl">
        <constructor-arg ref="SqlSessionTemplate"/>
    </bean>

• 将自己写的实现类注入到spring中，测试使用

    @Test
    public void test01()  {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapperImpl = context.getBean("userMapperImpl", UserMapper.class);
        List<User> users = userMapperImpl.selectUser();
        for (User user : users) {
            System.out.println(user);
        }
    }

注意

1. 不可以在两个地方同时注册mapper
   mybatis-config.xml里面和spring-bean.xml里面的
2. 我们通常将spring配置文件分来
   在spring-dao中编写sqlsession的配置，在applicationContext中配置bean
   在applicationContext中导入spring-dao就好了，作为总的文件。

实现方式二使用sqlSessionDaoSupport

• 编写接口实现类

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

• 注册bean

    <bean id="userMapperImpl2" class="com.yf.mapper.UserMapperImpl2">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>